Question:
What is the output of this program?
   #include<stdio.h>   #include<stdlib.h>   #include<netinet/in.h>   #include<sys/types.h>   #include<sys/socket.h>    int main()   {       int fd_server, fd_client, len, len_client;       struct sockaddr_in add_server;       fd_server = socket(AF_INET,SOCK_STREAM,0);       close(fd_server);           perror("accept");       if(listen(fd_server,5) != 0)           perror("listen");       fd_client = accept(fd_server,(struct sockaddr*)&add_server,&len);           if(fd_client == -1)       return 0;   }

Choices:
- syntax error
- error at the time of compilation
- segmentation fault
- none of the mentioned


Question:
On which system call, this program (process) waits until the server responds?
   #include<stdio.h>   #include<netinet/in.h>   #include<sys/types.h>   #include<sys/socket.h>    int main()   {       int fd_client,fd, len;       struct sockaddr_in add_server;       fd_client = socket(AF_INET,SOCK_STREAM,0);       if (fd_client == -1){           perror("fd_sock");           exit(1);   }   add_server.sin_family = AF_INET;   add_server.sin_port = ntohs(4001);   add_server.sin_addr.s_addr = inet_addr("127.0.0.1");   len = sizeof(add_server);   fd  = connect(fd_client,(struct sockaddr*)&add_server,len);   if(fd == -1)       perror("connect");       write(fd,"Hello\n",6);       return 0;   }

Choices:
- socket()
- connect()
- both socket() and connect()
- none of the mentioned


Question:
What is the the response of this server for this client if both programs are running on the same system?
   /*This is server.c*/    #include<stdio.h>   #include<stdlib.h>   #include<netinet/in.h>   #include<sys/types.h>   #include<sys/socket.h>    int main()   {       int fd_server, fd_client, len, len_client;       struct sockaddr_in add_server, add_client;       char buff[10];       fd_server = socket(AF_INET,SOCK_STREAM,0);       if (fd_server == -1)       {           perror("fd_sock");           exit(1);       }      add_server.sin_family = AF_INET;      add_server.sin_port = htons(4001);      add_server.sin_addr.s_addr = inet_addr("127.0.0.1");      len = sizeof(add_server);      len = sizeof(add_client);      if( bind(fd_server,(struct sockaddr*)&add_server,len) != 0)       perror("bind");       if(listen(fd_server,5) != 0)           perror("listen");       fd_client = accept(fd_server,(struct sockaddr*)&add_client,&len_client);       if(fd_client == -1)           perror("accept");       read(fd_client,buff,10);       return 0;   }   /*This is the client.c*/   #include<stdio.h>   #include<netinet/in.h>   #include<sys/types.h>   #include<sys/socket.h>    int main()   {       int fd_client,fd, len;       struct sockaddr_in add_server;       fd_client = socket(AF_INET,SOCK_STREAM,0);       if (fd_client == -1)       {           perror("fd_sock");           exit(1);       }       add_server.sin_family = AF_INET;       add_server.sin_port = ntohs(4001);       add_server.sin_addr.s_addr = inet_addr("127.0.0.1");       len = sizeof(add_server);       fd  = connect(fd_client,(struct sockaddr*)&add_server,len);       if(fd == -1)       perror("connect");       write(fd,"Hello\n",6);       return 0;   }

Choices:
- the server will write back to the client whatever the clinet will write to the server
- the client server communication will not work
- the response can not be determined
- none of the mentioned


Question:
In this example, the user has increased the text size in the browser. However not all text in this product spesification is increased. The heading and the button Copy URL is big, but not the details.
What is the reason that the text in the table is still small?

Choices:
- The font-size is set with em.
- The table width is fixed.
- The font-size is set with px.
- The font-size is not set for the table.


Question:
This example has a input field for zip code, with the autocomplete attribute:
<input type="tel" inputmode="numeric" pattern="[0-9]*" id="txtZip" name="sessionVO.zip" autocomplete="off">
Is this a correct way of using autocomplete?```
<input type="tel" inputmode="numeric" pattern="[0-9]*" id="txtZip" name="sessionVO.zip" autocomplete="off">
```

Choices:
- No, it should be autocomplete="postal-code"
- No, it should be autocomplete="false" instead of autfocomplete="off"
- Yes
- No, it should be autocomplete="zip-code"


Question: When was version 1.0 of the Web Content Accessibility Guidelines (WCAG) released?

Choices:
- 1995
- 2005
- 2008
- 1999


Question: What is Wave?

Choices:
- A screen reader
- An accessibility testing tool
- An initiative by W3C
- An organization of accessibility experts


Question: What is NVDA?

Choices:
- An accessibility testing tool
- An organization of accessibility experts
- A screen reader
- An initiative by W3C


Question: According to World Health Organization, how many people live with a disability?

Choices:
- About 5% or 400 000 000 people
- About 25 % or 2 000 000 000 people
- About 15% or 1 000 000 000 people


Question: At the top of the Lyft website, there is a logo, a search field, three navigation items and a profile icon. Which landmark should be used for this section?

Choices:
- <top>
- <nav>
- <head>
- <header>


Question: Still at the top, we have three navigation items and a profile icon. Which landmark should be used for this section?

Choices:
- <navigation>
- <section>
- <nav>
- None is needed, it is part of the <header>


Question: Under the top section is a banner about Covid. It is only visible on the front page of the site.Which landmark should be used on the banner?

Choices:
- It should be inside <header>
- <banner>
- It should be inside <main>
- No landmark needed. It is a temporary message that can be closed.


Question:
Clicking the logo takes on a web site, takes you to the front page of that site. Should this be a <button> or an <a>?```
<button>
``````
<a>
```

Choices:
- <a>
- <button>


Question:
Clicking the menu icon, the "hamburger", opens a full screen menu overlay.
Should the menu icon be a <button> or a <a>?```
<button>
``````
<a>
```

Choices:
- <a>
- <button>


Question:
You write this code for the button "Sign up to ride":Sign up to rideIs this code considered accessible?```
<a href="https://account.lyft.com" class="basebutton">Sign up to ride</a>
```

Choices:
- No, it looks like a button, so it should be coded as a <button>.
- No, the class name basebutton indicates that this sould be a <button>
- Yes, all good!


Question: Audio and video captions will mostly benefit?

Choices:
- People with hearing loss
- People with a broken arm
- People with a heavy accent


Question: In this example, we see white text on an image background.How should you measure this contrast?

Choices:
- Find the average color of the image, to measure against.
- Find the lightest part of the picture that might lie next to
- Not possible. Text on images is not accessible.


Question:
In this example from a chat window, the "Type your question" textarea is coded like this:
<textarea id="textarea" tabindex="0" placeholder="Type your question" aria-invalid="false"></textarea>
Is this textarea accessible?```
<textarea id="textarea" tabindex="0" placeholder="Type your question" aria-invalid="false"></textarea>
```

Choices:
- No, it is missing a valid label. Placeholder is not a valid label.
- No, it has tabindex="0" that disable keyboard access
- Yes


Choices:
-
<button aria-label="Select phone number country code" aria-expanded="false" aria-controls="core-ui-id-5005823451-popover">
  <img src="gb.svg">
  <svg width="16" height="16" viewBox="0 0 16 16" style="fill: var(--core-ui-theme-icon-secondary,rgba(12,11,49,0.7));">
    <path d="…"></path>
  </svg>
</button>
-
<button aria-label="Select phone number country code" aria-expanded="false" aria-controls="core-ui-id-5005823451-popover">
  <img src="gb.svg">
  <svg width="16" height="16" viewBox="0 0 16 16" style="fill: var(--core-ui-theme-icon-secondary,rgba(12,11,49,0.7));">
    <path d="…"></path>
  </svg>
</button>


Question: In this example from Booking, the link to Italy is focused. They have relied on the browser default styling. However, the outline is only on the left and right side of the linked section. What might be a reason that there is no outline at the top and bottom?

Choices:
- outline-top: 0; and outline-bottom: 0;
- overflow: hidden;


Question:
This screenshot from India Today shows three news articles. The structure is:

News

What is wrong with...

Mithun Chakraborty set to join....

Rome Ranking series: Vinesh Phogat wins 2nd gold medal
Is this a good outline?```
<h1>News
``````
<h2>What is wrong with...
``````
<h3>Mithun Chakraborty set to join....
``````
<h3>Rome Ranking series: Vinesh Phogat wins 2nd gold medal
```

Choices:
- Yes. The <h2> is the most important one.
-
No, the two
s are not subheadings of the
. They are not related at all. They should be
s.


Question: This screenshot is from The Salvation Army. The text "founded in 1865 by William Booth" is a link. This is a good link text because it indicates that the link takes us to the history of the army.

Choices:
- False
- True


Question:
Opening the Honda web site, a screen reader will read the first interactive element as something like:
link, image, aitch tee tee pee ess colon slash slash double-u double-u double-u dot honda dot com slash (link, image, https://www.honda.com/)
Why do we hear this?

Choices:
- A screen reader will always read the destination of a link.
- The site has not implemented aria attributes to support screen readers.
- The image is missing alternative text.


Question:
The navigation link "Mission" is showed in a hover state.(Ignore the fact that hover states are not common on phones)The background is #dc2c30. What are possible problems with this hover state?```
#dc2c30
```

Choices:
- Text size is too small
- It uses color alone to tell the state
- The contrast is insufficient
- No problems


Question: This screenshot from AliExpress shows an icon of a magnifying glass at the top.What would be the best descriptive text?

Choices:
- Open search
- Search
- "Black icon of a magnifying glass"
- None. It should be empty. The user understands that this is search.


Question: This screenshot shows AliExpress with a logo, a search field and category icons.Is the logo a meaningful image?

Choices:
- Yes, the logo tells the users which site it is and offers a link to the front page.
- No, the logo is decorative. The user already knows that this is AliExpress from the title and the address.


Question: This table shows the status of Facebook messages.The status "sent" is written in green. Is that accessible?

Choices:
- No, color as meaning is not accessible for color blind users.
- Yes, color is not used alone. The text sent is sufficient.


Question: Which database is ideal for large organizations and enterprises?

Choices:
- MySQL
- PostgreSQL
- Amazon Aurora


Question: Can all accounts of an AWS Organization be billed with a single bill?

Choices:
- Yes
- No


Question: Which AWS service helps you build text chatbots?

Choices:
- Amazon Transcribe
- Amazon Lex
- Amazon Polly
- Amazon Comprehend


Question: AWS Artifact is a service that provides access to AWS security and complicance reports.

Choices:
- True
- False


Question: Who is responsible of managing storage and database in AWS Cloud?

Choices:
- AWS
- Customers


Question: Economies of scale continually reduce AWS Cloud pricing.

Choices:
- True
- False


Question: If an instance store reboots, does the data in the instance persist?

Choices:
- No
- Yes


Question: Which pillar of the AWS Well-Architected Framework focuses on recovering from service or infrastructure disruptions?

Choices:
- Reliability
- Operational excellence
- Performance efficiency


Question: Which perspective of the AWS Cloud Adoption Framework focuses on minimizing the business risks?

Choices:
- Governance Perspective
- Operations Perspective
- People Perspective
- Business Perspective


Question: Which of the following is AWS Migration Strategy?

Choices:
- Replatforming
- Auditability
- Governance


Question: What is the purpose of AWS Organizations service?

Choices:
- AWS Organizations helps you manage multiple AWS Accounts
- AWS Organizations groups your applications and manages them
- AWS Organizations organizes your services and makes service usage reports
- AWS Organizations optimizes your system performance


Question: Denial-of-Service (DoS) attack comes from different sources.

Choices:
- True
- False


Question: Which service sends and receives messages between application components?

Choices:
- AWS Simple Queue Service (AWS SQS)
- AWS Snowmbile
- AWS Lambda
- AWS CloudTrail


Question: Which sentence best describes AWS CloudWatch?

Choices:
- CloudWatch is a monitoring service that monitors your resources, and configures automatic alarms.
- CloudWatch monitors your account and recommends you cost optimization and performance improvement actions.
- CloudWatch is a service tha logs your AWS environment Actions. It is used to create events that describe how your application is being used.


Question: Which AWS database service proviced historical data of your application changes?

Choices:
- AWS ElastiCache
- AWS DocumentDB
- AWS Neptune
- AWS Quantum Ledger Database


Question: Based on application's network requests, AWS Web Application Firewall can block network traffic.

Choices:
- False
- True


Question: With AWS EC2 you only pay for the compute time that you use.

Choices:
- True
- False


Question: Containers are an essential concept in microservice architectures.

Choices:
- False
- True


Question: What does AWS Marketplace allows you to do?

Choices:
- AWS Marketplace lets you list and sell software
- AWS Marketplace lets you see the cost analysis of all AWS Cloud Services
- AWS Marketplace lets you list all AWS Cloud Services


Question: Which AWS service do you need to use to get complete history of user activity?

Choices:
- AWS CloudTrail
- AWS CloudWatch
- AWS TrustedAdvisor


Question: What is AWS DynamoDB Accelerator capable of?

Choices:
- Improves read times of non-relational data
- Improves write times of documents
- Improves read times of relational data
- Improves visualisation times of graphs


Question: What are Edge Locations?

Choices:
- Data centers that deliver data fast to the users
- Physical hard drives
- Data centers that store petabytes of data
- AWS Regions


Question: What does AWS Shield protects from?

Choices:
- Infrastructure threats
- Software vulnerabilities
- Dos and DDoS attacks


Question: Who is responsible of managing platform and custmer data in the AWS Cloud?

Choices:
- AWS
- Customers


Question: How is called a service that lets you run code without needing to think about servers?

Choices:
- AWS ECS
- AWS Serverless
- AWS EC2 Auto Scaling
- AWS Lambda


Question: What is an IAM Policy?

Choices:
- IAM Policy is an entity that interacts with AWS resources or services
- IAM Policy is a temporary access to AWS services or resources
- IAM Policy is a document that customizes user permissions for AWS services and resources


Question: Which tool lets you visualise and manage your AWS costs?

Choices:
- AWS Price Calculator
- AWS Budgets
- AWS Cost Explorer


Question: Which AWS storage service is designed to transfer petabytes of data in and out of the cloud

Choices:
- AWS S3
- AWS Redshift
- AWS Snowmobile


Question: AWS Elastic Block Store Snapshot is:

Choices:
- Full data backup
- Differential data backup
- Incremental data backup


Question: Which AWS service manages encryption and decryption of data?

Choices:
- AWS GuardDuty
- AWS WAF
- AWS Key Management Service (AWS KMS)
- AWS Inspector


Question: DNS stands for "Data Name System".

Choices:
- False
- True


Question: What is AWS EFS?

Choices:
- AWS Elastic File System
- AWS Enterprise File System
- AWS Efficient File System


Question: Which AWS service helps you create users and provide them security access?

Choices:
- AWS Redshift
- AWS CloudFormation
- AWS Direct Connect
- AWS Identity and Access Management (IAM)


Question: AWS Regions is part of the AWS Global Infrastructure.

Choices:
- True.
- False.


Question: What is AWS EC2?

Choices:
- AWS EC2 is a virtual server in the AWS Cloud
- AWS EC2 is a serverless compute service
- AWS EC2 is a resource monitoring service
- AWS EC2 is a data center


Question: What kind of database is AWS DynamoDB?

Choices:
- NoSQL database
- Relational database
- Document database


Question: Which AWS service reduces network latency?

Choices:
- Amazon CloudFront
- Elastic Load Balancing
- AWS Transit Gateway
- AWS Direct Connect


Question: Which Amazon S3 storage class has the lowest cost?

Choices:
- S3 Inteligent-Tiering
- S3 Glacier Deep Archive
- S3 Standard


Question: AWS Elastic Beanstalk is a service that manages web infrastructure.

Choices:
- False
- True


Question: Leapfrog migration strategy allows faster development of new features with less risk that the Strangler strategy.

Choices:
- True
- False


Question: What are CloudWatch metrics used for?

Choices:
- They are used to analyze Lambda failures
- They are used to monitor network trafic
- They are used by developers to monitor service health
- They are used to automate responses to possible security risks


Question: One of the best practices for securing serverless architecture is to secure data at transit and the rest.

Choices:
- False
- True


Question: One of the best practices for securing serverless architecture is to secure data at transit and the rest.

Choices:
- True
- False


Question: Which sentence is true for Amazon Kinesis?

Choices:
- Amazon Kinesis provides distributed tracing for every Lambda function or API stage in API Gateway
- Amazon Kinesis is a streaming service that allows you to process a large amount of data in real time
- Amazon Kinesis is a serverless computing solution that is greatly suited to your workload


Question: Which statement is true for the AWS Step Functions?

Choices:
- All three statements are true
- AWS Step functions are functions that work in steps
- Each step is monitored and logged
- It has built-in automatic retries should a step fail


Question: Which service can be used for application authenthication?

Choices:
- Amazon S3
- AWS AppSync
- Amazon Cognito
- AWS X-Ray


Question: What does Amazon SQS stand for?

Choices:
- Amazon Simple Queue Service
- Amazon Standard Quote Service
- Amazon Simple Query Service


Question: Asynchronous code does not need to wait for the execution of other code blocks.

Choices:
- True
- False


Question: What are WebSockets?

Choices:
- Automated responses that inform about possible security risks
- Methods for visualizing and coordinating your workflow
- An open standard for persistent client-server connections


Question: Which slogan is a core of testing for peak load?

Choices:
- Analyze, test, build, migrate
- Build, measure, learn, repeat
- Test, validate, deploy


Question: Which one is considered a best practice for a serverless scaling?

Choices:
- Separate database and application
- Refactor your application as less as possible
- Use local infrastructure
- Implement error handling


Question: What is Concurrency?

Choices:
- It is a storage service
- It is a data decryption service
- It is the number of simultaneous Lambda invocations


Question: With Step Functions you can see the execution history of a function.

Choices:
- False
- True


Question: What is Client Polling?

Choices:
- It is a technique to improve on the polling strategy
- It is a standard method for obtaining status information on a long-running transaction
- It is a two-way connection between the server and the client
- It is a fast data processing service


Question: Which one is better for larger processes or deployment bundles?

Choices:
- AWS Fargate
- AWS Lambda


Question: Should you keep sensitive data in your code?

Choices:
- Yes
- No


Question: What does AWS DMS stand for?

Choices:
- AWS Database Management Service
- AWS Database Migration Service
- AWS Deployment Management Service


Question: What is AWS SAM?

Choices:
- It is a serverless application deployment module for AWS CloudFormation
- It is a service that handles massive amounts of data
- It is a service that helps you watch your serverless apps


Question: Which phase is the first phase of a CI/CD pipeline?

Choices:
- Test phase
- Source phase
- Production phase
- Build phase


Question: A CI/CD pipeline automates software deployment procedures and standardizes quality checks.

Choices:
- True
- False


Question: Which sentence is true for AWS CloudTrail?

Choices:
- AWS CloudTrail keeps track of your account's user API activity
- AWS CloudTrail helps you find errors in your Lambda executions
- AWS CloudTrail helps you return your code to previous version
- AWS CloudTrail defines desired configuration settings


Question: What AWS Key Management Service used for?

Choices:
- To help you with application deployment
- To manage Lambda function execution
- To encrypt the data


Question: Are there Lambda built-in retries in error handling for synchronous events?

Choices:
- No
- Yes


Question: Which operator is used to multiply numbers?

Choices:
- x


Question: Array indexes start with:

Choices:
- 0
- 1


Question: What is the name of the 'special' class that represents a group of constants?

Choices:
- special
- const
- void
- enum


Question: In C#, it is possible to inherit fields and methods from one class to another.

Choices:
- True
- False


Question: What is the correct way to create an object called myObj of MyClass?

Choices:
- class myObj = new MyClass();
- MyClass myObj = new MyClass();
- new myObj = MyClass();
- class MyClass = new myObj();


Question: Which keyword is used to create a class in C#?

Choices:
- MyClass
- class
- class()
- className


Question: How do you call a method in C#?

Choices:
- MyMethod();
- MyMethod;
- (MyMethod);
- myMethod[];


Question: How do you create a method in C#?

Choices:
- MyMethod.
- myMethod[]
- MyMethod()
- (MyMethod)


Question: To declare an array in C#, define the variable type with:


Question: Which property can be used to find the length of a string?

Choices:
- getLength()
- length
- length()
- Length


Question: C# is an alias of C++

Choices:
- False
- True


Question: Type casting is when you assign a value of one data type to another type.

Choices:
- True
- False


Question: The value of a string variable can be surrounded by single quotes.

Choices:
- True
- False


Question: Which operator is used to add together two values?

Choices:
- The & sign
- The * sign
- The + sign


Question: How do you create a variable with the floating number 2.8?

Choices:
- int x = 2.8;
- byte x = 2.8
- double x = 2.8D;
- int x = 2.8D;


Question: How do you create a variable with the numeric value 5?

Choices:
- double x = 5;
- x = 5;
- num x = 5
- int x = 5;


Question: Which data type is used to create a variable that should store text?

Choices:
- myString
- Txt
- str
- string


Question: How do you insert COMMENTS in C# code?

Choices:
- # This is a comment
- // This is a comment
- /* This is a comment


Question: Which access modifier makes the code only accessible within the same class?

Choices:
- public
- final
- abstract
- private


Question: Which operator can be used to compare two values?


Question: How do you start writing an if statement in C#?

Choices:
- if x > y then:
- if (x > y)
- if x > y:


Question: What is a correct syntax to output "Hello World" in C#?

Choices:
- Console.WriteLine("Hello World");
- print ("Hello World");
- cout << "Hello World";
- System.out.println("Hello World");


Question: Which keyword is used to return a value inside a method?

Choices:
- break
- get
- return
- void


Question: How do you start writing a while loop in C#?

Choices:
- while x > y:
- while x > y {
- x > y while {
- while (x > y)


Question: SIEM is commonly used to

Choices:
- Do a real-time analysis of security alerts generated by applications, hosts and network hardware
- Secure the servers that are hosted in the cloud
- Preventively block attacks against networks


Question: Which 3 levels in OSI Model are usually implemented in the software within the operating system?

Choices:
- Application, Presentation, Session
- Data Link, Transport, Application
- Transport, Session, Presentation


Question: Which of these protocols reside in Layer 3 - Network in the OSI Model?

Choices:
- IP and TCP
- IP and IPSec
- TCP and IPSec


Question: A netmask can be represented by which two ways?

Choices:
- Decimal Numbers (Netmask: 255.255.255.0) and Slash Notation (80.212.212.50/32)
- Pound Notation (80.2012.212.50#24) and Decimal Numbers (Netmask: 255.255.255.0)
- Slash Notation (80.212.212.50/32) and Pound Notation (80.2012.212.50#24)


Question: Which is the broadcast address in this network: 172.16.24.0/24

Choices:
- 172.16.24.255
- 172.16.24.0
- 172.16.24.1


Question: Which one of these is a RFC 1918 ip address?

Choices:
- 172.17.1.30
- 172.16.1.30
- 9.0.0.1


Question: Shortening an IPv6 address means:

Choices:
- Removing unused groups of hexadecimal numbers
- Converting 8 groups of 4 hexadecimal numbers into a valid IPv4 address
- Removing a group of only 0's


Question: What is spoofing?

Choices:
- Falsifying data, making something appear different than they really are
- A way of terminating a 3-way handshake connection
- A way server hides from attacks, a defensive mechanics


Question: You need an IDS (Intrusion Detection System) in addition to IPS (Intrusion Prevention System) to be able to both detect and prevent access

Choices:
- False. IPS is also able to detect if positioned correctly in the network
- True. IDS and IPS are two separate product or devices, with designed roles on different parts of the network. IDS tells the IPS to block/prevent.
- Neither of the other options are correct


Question: To be able to detect and block specific file types/documents to be blocked from downloading from the internet, with a firewall, you need:

Choices:
- A Next-Generation Firewall with phaser features
- A Next-Generation Firewall with layer 6 features
- A Next-Generation Firewall with layer 7 features


Question: A cookie can not be used to control a users session/state

Choices:
- True, only supercookies have this feature
- False. Cookies are often used for tracking sessions


Question: Which types of packets can be used to determine if a system is alive on the network?

Choices:
- ICMP handshake Request, TCP ACK, NMAP
- ICMP Echo Request, ICMP Timestamp Request, TCP SYN, TCP ACK
- ICMP Echo Request, TCP SYN, SW-1TCH, ICMP Timestamp Request


Question: ARP Scanning can only be used to identify hosts/systems on the LAN

Choices:
- False
- True


Question: NMAP Timing options (-T) can be used to to avoid detection by

Choices:
- Limit speed on how fast hosts are scanned
- Choose when to scan. E.g. only scan during the night
- Timing option is used to time a scan to CPU clocks, so they are in sync, for more efficient scanning


Question: What is a strobe of data?

Choices:
- Small amount of traffic trying to hide from detecting
- A sudden increase of traffic in the network


Question: What is IDOR?

Choices:
- Insecure Door or Room
- Invalid Data or Reference
- Insecure Direct Object Reference


Question: What is SQL injection?

Choices:
- It is used to inject malicious code to a database server, through a query
- It is used in Buffer Overflow attacks to overwrite memory
- It is used to spoof or inject false headers in a HTTP request


Question: What is best practice in defending against SQL injection?

Choices:
- Blocking specific ports that SQL injections are usually attacked via
- Programmers will not make web applications that allow user input
- Sanitizing users input in a web application


Question: What is CSP - Content Security Policy?

Choices:
- A strict way of sanitizing user input on a website
- A strict way of controlling where javascript is allowed to be executed from
- TLS encryption between server and client


Question: Which order of security protocols is correct, going from least to most secure?

Choices:
- WPA, WEP, WPA2, WPA3
- WEP, WPA, WPA2, WPA3
- WPA, WPA2, WPA3, WEP


Question: The 6 stages of PICERL are:

Choices:
- Preparation, Identification, Containment, Eradication, Recovery, Vacation
- Preparation, Identification, Containment, Eradication, Recovery, Payment
- Preparation, Identification, Containment, Eradication, Recovery, Lessons Learned


Question: Classifications of incidents should generally be according to

Choices:
- Category, sensitivity, criticality, SLA, contact channel
- Category, sensitivity, criticality
- Category, sensitivity, criticality, SLA


Question: Using the same strong password, with high entropy, on multiple sites is good practice

Choices:
- True. Storing passwords in clear text in database is no longer practiced and are now only using strong encryption
- False. If one site is breached/hacked and stores passwords in clear text, your password is now in hackers hands


Question: What is Zero-Trust architecture?

Choices:
- A network where only some resources/devices are trusted
- A network where all systems/resources need explicit access to be able to communicate
- A network where we do not trust public network(internet), but we trust local network


Question: Which one of the following algorithm is not used in asymmetric key cryptography?

Choices:
- RSA Algorithm
- Diffie-Hellman Algorithm
- Electronic Code Book Algorithm
- None of the above


Question: Every host in an IPv4 network has a 1-second resolution real-time clock with battery backup. Each host needs to generate up to 1000 unique identifiers per second. Assume that each host has a globally unique IPv4 address. Design a 50-bit globally unique ID for this purpose. After what period (in seconds) will the identifiers generated by a host wrap around?

Choices:
- 128
- 64
- 256
- 512


Question: An IP router with a Maximum Transmission Unit (MTU) of 1500 bytes has received an IP packet of size 4404 bytes with an IP header of length 20 bytes. The values of the relevant fields in the header of the third IP fragment generated by the router for this packet are

Choices:
- MF bit: 0, Datagram Length: 1444; Offset: 370
- MF bit: 1, Datagram Length: 1424; Offset: 185
- MF bit: 1, Datagram Length: 1500; Offset: 37
- MF bit: 0, Datagram Length: 1424; Offset: 2960


Question: Station A needs to send a message consisting of 9 packets to Station B using a sliding window (window size 3) and go-back-n error control strategy. All packets are ready and immediately available for transmission. If every 5th packet that A transmits gets lost (but no acks from B ever get lost), then what is the number of packets that A will transmit for sending the message to B?

Choices:
- 12
- 14
- 16
- 18


Question: The address resolution protocol (ARP) is used for

Choices:
- Finding the IP address from the DNS
- Finding the IP address of the default gateway
- Finding the IP address that corresponds to a MAC address
- Finding the MAC address that corresponds to an IP address


Question: In a packet switching network, packets are routed from source to destination along a single path having two intermediate nodes. If the message size is 24 bytes and each packet contains a header of 3 bytes, then the optimum packet size is:

Choices:
- 4
- 6
- 7
- 9


Question: Consider the given network implementation scenario. For the given classful NID 199.10.20.0/24, the requirement is to create 13 subnets. With given details, find the range of first and last valid IP in 15th subnet.

Choices:
- 199.10.20.208 to 199.10.20.222
- 199.10.20.225 to 199.10.20.238
- 199.10.20.193 to 199.10.20.206
- Not of these


Question:
The routing table of a router is shown below:
 Destination     Sub net mask 	     Interface
 128.75.43.0 	 255.255.255.0 	        Eth0
 128.75.43.0 	 255.255.255.128 	Eth1
 192.12.17.5 	 255.255.255.255 	Eth3
 default 	  	                Eth2
On which interfaces will the router forward packets addressed to destinations 128.75.43.16 and 192.12.17.10 respectively?

Choices:
- Eth1 and Eth2
- Eth0 and Eth2
- Eth0 and Eth3
- Eth1 and Eth3


Question:
Consider three IP networks A, B and C. Host HA in network A sends messages each containing 180 bytes of application data to a host HC in network C. The TCP layer prefixes a 20 byte header to the message. This passes through an intermediate network B. The maximum packet size, including 20 byte IP header, in each network is
A : 1000 bytes
B : 100 bytes
C : 1000 bytes
The network A and B are connected through a 1 Mbps link, while B and C are connected by a 512 Kbps link (bps = bits per second).

Assuming that the packets are correctly delivered, how many bytes, including headers, are delivered to the IP layer at the destination for one application message, in the best case ? Consider only data packets.

Choices:
- 200
- 220
- 240
- 260


Question:
Consider three IP networks A, B and C. Host HA in network A sends messages each containing 180 bytes of application data to a host HC in network C. The TCP layer prefixes a 20 byte header to the message. This passes through an intermediate network B. The maximum packet size, including 20 byte IP header, in each network is
A : 1000 bytes
B : 100 bytes
C : 1000 bytes
The network A and B are connected through a 1 Mbps link, while B and C are connected by a 512 Kbps link (bps = bits per second).

What is the rate at which application data is transferred to host HC? Ignore errors, acknowledgements, and other overheads.

Choices:
- 325.5 Kbps
- 354.5 Kbps
- 409.6 Kbps
- 512.0 Kbps


Question: Packets of the same session may be routed through different paths in

Choices:
- TCP, but not UDP
- TCP and UDP
- UDP, but not TCP
- Neither TCP, nor UDP


Question: The maximum window size for data transmission using the selective reject protocol with n-bit frame sequence numbers is:

Choices:
- 2^n
- 2^(n-1)
- 2^n – 1
- 2^(n-2)


Question: Which of the following functionalities must be implemented by a transport protocol over and above the network protocol ?

Choices:
- Recovery from packet losses
- Detection of duplicate packets
- Packet delivery in the correct order
- End to end connectivity


Question: Which of the following is NOT true about User Datagram Protocol in transport layer?

Choices:
- Works well in unidirectional communication, suitable for broadcast information.
- It does three way handshake before sending datagrams
- It provides datagrams, suitable for modeling other protocols such as in IP tunneling or Remote Procedure Call and the Network File System
- The lack of retransmission delays makes it suitable for real-time applications


Question:
Suppose two hosts use a TCP connection to transfer a large file. Which of the following statements is/are False with respect to the TCP connection?
1. If the sequence number of a segment is m, then the sequence
   number of the subsequent segment is always m+1.
2. If the estimated round trip time at any given point of time
   is t sec, the value of the retransmission timeout is always
   set to greater than or equal to t sec.
3. The size of the advertised window never changes during the
   course of the TCP connection.
4. The number of unacknowledged bytes at the sender is always
   less than or equal to the advertised window

Choices:
- 3 only
- 1 and 3 only
- 1 and 4 only
- 2 and 4 only


Question: A link has a transmission speed of 106 bits/sec. It uses data packets of size 1000 bytes each. Assume that the acknowledgment has negligible transmission delay, and that its propagation delay is the same as the data propagation delay. Also assume that the processing delays at nodes are negligible. The efficiency of the stop-and-wait protocol in this setup is exactly 25%. The value of the one-way propagation delay (in milliseconds) is ___________.

Choices:
- 4
- 8
- 12
- 16


Question: Identify the correct order in which a server process must invoke the function calls accept, bind, listen, and recv according to UNIX socket API.

Choices:
- listen, accept, bind recv
- bind, listen, accept, recv
- bind, accept, listen, recv
- accept, listen, bind, recv


Question: Assume that the bandwidth for a TCP connection is 1048560 bits/sec. Let α be the value of RTT in milliseconds (rounded off to the nearest integer) after which the TCP window scale option is needed. Let β be the maximum possible window size with window scale option. Then the values of α and β are.

Choices:
- 63 milliseconds 65535 × 214
- 63 milliseconds 65535 × 216
- 500 milliseconds 65535 × 214
- 500 milliseconds 65535 × 216


Question:
Consider the following statements.
I. TCP connections are full duplex.
II. TCP has no option for selective acknowledgment
III. TCP connections are message streams.

Choices:
- Only I is correct
- Only I and II are correct
- Only II and III are correct
- All of I, II and III are correct


Question: Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is 500 × 106 bits per second. The propagation speed of the media is 4 × 106 meters per second. It is needed to design a Go-Back-N sliding window protocol for this network. The average packet size is 107 bits. The network is to be used to its full capacity. Assume that processing delays at nodes are negligible. Then, the minimum size in bits of he sequence number field has to be ________.

Choices:
- 2
- 4
- 8
- 16


Question: In networking terminology UTP means

Choices:
- Ubiquitous teflon port
- Uniformly terminating port
- Unshielded twisted pair
- Unshielded T-connector port


Question: If there are n devices (nodes) in a network, what is the number of cable links required for a fully connected mesh and a star topology respectively

Choices:
- n(n −1) / 2, n
- n, n −1
- n −1, n
- n −1, n(n −1) / 2


Question: What is WPA?

Choices:
- wired protected access
- wi-fi protected access
- wired process access
- wi-fi process access


Question: SATA is the abbreviation of

Choices:
- Serial Advanced Technology Attachment
- Serial Advanced Technology Architecture
- Serial Advanced Technology Adapter
- Serial Advanced Technology Array


Question:
Host A (on TCP/IP v4 network A) sends an IP datagram D to host B (also on TCP/IP v4 network B). Assume that no error occurred during the transmission of D. When D reaches B, which of the following IP header field(s) may be different from that of the original datagram D?
(i) TTL
(ii) Checksum
(iii) Fragment Offset

Choices:
- (i) only
- (i) and (ii) only
- (ii) and (iii) only
- (i), (ii) and (iii)


Question: Using p = 3, q = 13, d = 7 and e = 3 in the RSA algorithm, what is the value of ciphertext for a plain text 5 ?

Choices:
- 8
- 16
- 26
- 33


Question: Which of the following encryption algorithms is based on the Fiestal structure?

Choices:
- Advanced Encryption Standard
- RSA public key cryptographic algorithm
- Data Encryption Standard
- RC4


Question:
Encrypt the plain text Message “EXTRANET” using Transposition cipher technique with the following key:

Using ‘Z’ as bogus character.

Choices:
- TAXERTZENZ
- EXTRANETZZ
- EZXZTRZANZET
- EXTZRANZETZ


Question: Which of the following control fields in TCP header is used to specify whether the sender has no more data to transmit?

Choices:
- FIN
- RST
- SYN
- PSH


Question: Silly Window Syndrome is related to

Choices:
- Error during transmission
- File transfer protocol
- Degrade in TCP performance
- Interface problem


Question: SSL is not responsible for

Choices:
- Mutual authentication of client & server
- Secret communication
- Data Integrity protection
- Error detection and correction


Question:
A TCP server application is programmed to listen on port number P on host S. A TCP client is connected to the TCP server over the network.

Consider that while the TCP connection was active, the server machine S crashed and rebooted. Assume that the client does not use the TCP keepalive timer. Which of the following behaviors is/are possible?

Choices:
- If the client was waiting to receive a packet, it may wait indefinitely
- The TCP server application on S can listen on P after reboot
- If the client sends a packet after the server reboot, it will receive a RST segment
- If the client sends a packet after the server reboot, it will receive a FIN segment


Question: Match the following:

Choices:
- (1)
- (2)
- (3)
- (4)


Question: What is the maximum size of data that the application layer can pass on to the TCP layer below?

Choices:
- A
- B
- C
- D


Question: The protocol data unit (PDU) for the application layer in the Internet stack is

Choices:
- Segment
- Datagram
- Message
- Frame


Question: What is one advantage of setting up a DMZ(Demilitarized Zone) with two firewalls?

Choices:
- You can control where traffic goes in the three networks
- You can do stateful packet filtering
- You can do load balancing
- Improve network performance


Question:
Consider the set of activities related to e-mail

A : Send an e-mail from a mail client to mail server
B : Download e-mail headers from mail box and retrieve mails from server to a cache
C : Checking e-mail through a web browser

The application level protocol used for each activity in the same sequence is

Choices:
- SMTP, HTTPS, IMAP
- SMTP, POP, IMAP
- SMTP, IMAP, HTTPS
- SMTP, IMAP, POP


Question: A packet filtering firewall can

Choices:
- deny certain users from accessing a service
- block worms and viruses from entering the network
- disallow some files from being accessed through FTP
- block some hosts from accessing the network


Question: What is the size of the ‘total length’ field in IPv4 datagram?

Choices:
- 4 bit
- 8 bit
- 16 bit
- 32 bit


Question: Bit stuffing refers to

Choices:
- inserting a \'0\' in user stream to differentiate it with a flag
- inserting a \'0\' in flag stream to avoid ambiguity
- appending a nibble to the flag sequence
- appending a nibble to the use data stream


Question: Which of the following protocols is an application layer protocol that establishes, manages and terminates multimedia sessions ?

Choices:
- Session Maintenance Protocol
- Real - time Streaming Protocol
- Real - time Transport Control Protocol
- Session Initiation Protocol


Question: Assume that Source S and Destination D are connected through an intermediate router R. How many times a packet has to visit the network layer and data link layer during a transmission from S to D?

Choices:
- Network layer – 4 times, Data link layer – 4 times
- Network layer – 4 times, Data link layer – 6 times
- Network layer – 2 times, Data link layer – 4 times
- Network layer – 3 times, Data link layer – 4 times


Question: Consider a link with packet loss probability of 0.2. What is the expected number of transmissions it would take to transfer 200 packets given that the stop and wait protocol is used?

Choices:
- 125
- 250
- 225
- 150


Question: Consider the cyclic redundancy check (CRC) based error detecting scheme having the generator polynomial X3+X+1. Suppose the message m4m3m2m1m0 = 11000 is to be transmitted. Check bits c2c1c0 are appended at the end of the message by the transmitter using the above CRC scheme. The transmitted bit string is denoted by m4m3m2m1m0c2c1c0. The value of the checkbit sequence c2c1c0 is

Choices:
- 101
- 110
- 100
- 111


Question: Consider a network using the pure ALOHA medium access control protocol, where each frame is of length 1,000 bits. The channel transmission rate is 1 Mbps (=106 bits per second). The aggregate number of transmissions across all the nodes (including new frame transmissions and retransmitted frames due to collisions) is modelled as a Poisson process with a rate of 1,000 frames per second. Throughput is defined as the average number of frames successfully transmitted per second. The throughput of the network (rounded to the nearest integer) is ______________ .

Choices:
- 130 to 140
- 140 to 150
- 120 to 130
- 100 to 110


Question: In a RSA cryptosystem, a participant A uses two prime numbers p=13 and q=11 to generate his public and private keys. If the public key of A is 37, then the private key of A is _____.

Choices:
- 18
- 23
- 11
- 13


Question:
Which of the following are used to generate a message digest by the network security protocols?
(P) SHA-256
(Q) AES
(R) DES
(S) MD5

Choices:
- P and S only
- P and Q only
- R and S only
- P and R only


Question: MD5 is a widely used hash function for producing hash value of

Choices:
- 64 bits
- 128 bits
- 512 bits
- 1024 bits


Question: Pretty Good Privacy (PGP) is used in

Choices:
- Browser security
- FTP security
- Email security
- None of the above


Question: An attacker sits between the sender and receiver and captures the information and retransmits to the receiver after some time without altering the information. This attack is called as _____.

Choices:
- Denial of service attack
- Masquarade attack
- Simple attack
- Complex attack


Question: In a system an RSA algorithm with p=5 and q=11, is implemented for data security. What is the value of the decryption key if the value of the encryption key is 27?

Choices:
- 3
- 7
- 27
- 40


Question: An attacker sits between customer and Banker, and captures the information from thecustomer and retransmits to the banker by altering the information. This attack is called as ______.

Choices:
- Masquerade Attack
- Replay Attack
- Passive Attack
- Denial of Service Attack


Question: An Ethernet frame that is less than the IEEE 802.3 minimum length of 64 octets is called

Choices:
- Short frame
- Small frame
- Mini frame
- Runt frame


Question: Four channels are multiplexed using TDM. If each channel sends 100 bytes/second and we multiplex 1 byte per channel, then the bit rate for the link is __________.

Choices:
- 400 bps
- 800 bps
- 1600 bps
- 3200 bps


Question: What frequency range is used for microwave communications, satellite and radar?

Choices:
- Low frequency: 30 kHz to 300 kHz
- Medium frequency: 300 kHz to 3 MHz
- Super high frequency: 3000 MHz to 30000 MHz
- Extremely high frequency: 30000 kHz


Question: What is compression ratio in a typical mp3 audio files?

Choices:
- 4:1
- 6:1
- 8:1
- 10:1


Question: Which of the following objects can be used in expressions and scriplets in JSP (Java Server Pages) without explicitly declaring them?

Choices:
- session and request only
- request and response only
- response and session only
- session, request and response


Question: In the TCP/IP protocol suite, which one of the following is NOT part of the IP header?

Choices:
- Fragment Offset
- Source IP address
- Destination IP address
- Destination port number


Question: On a TCP connection, current congestion window size is Congestion Window = 4 KB. The window size advertised by the receiver is Advertise Window = 6 KB. The last byte sent by the sender is LastByteSent = 10240 and the last byte acknowledged by the receiver is LastByteAcked = 8192. The current window size at the sender is

Choices:
- 2048 bytes
- 4096 bytes
- 6144 bytes
- 8192 bytes


Question: For a host machine that uses the token bucket algorithm for congestion control, the token bucket has a capacity of 1 megabyte and the maximum output rate is 20 megabytes per second.  Tokens arrive at a rate to sustain output at a rate of 10 megabytes per second. The token bucket is currently full and the machine needs to send 12 megabytes of data. The minimum time required to transmit the data is _________________ seconds.

Choices:
- 1.1
- 0.1
- 2.1
- 2.0


Question:
Consider the following statements about the timeout value used in TCP.
i. The timeout value is set to the RTT (Round Trip Time) measured during TCP connection establishment for the entire duration of the connection.
ii. Appropriate RTT estimation algorithm is used to set the timeout value of a TCP connection.
iii. Timeout value is set to twice the propagation delay from the sender to the receiver.
Which of the following choices hold?

Choices:
- (i) is false, but (ii) and (iii) are true
- (i) and (iii) are false, but (ii) is title
- (i) and (ii) are false, but (iii) is true
- (i), (ii) and (iii) are false


Question:
Consider a TCP connection in a state where there are no outstanding ACKs. The sender sends two segments back to back. The sequence numbers of the first and second segments are 230 and 290 respectively. The first segment was lost, but the second segment was received correctly by the receiver. Let X be the amount of data carried in the first segment (in bytes), and Y be the ACK number sent by the receiver.
The values of X and Y (in that order) are

Choices:
- 60 and 290
- 230 and 291
- 60 and 231
- 60 and 230


Question:
Which of the following statements are TRUE?

(S1)  TCP handles both congestion and flow control
(S2)  UDP handles congestion but not flow control
(S3)  Fast retransmit deals with congestion but not flow control
(S4)  Slow start mechanism deals with both congestion and flow control

Choices:
- S1, S2 and S3 only
- S1 and S3 only
- S3 and S4 only
- S1, S3 and S4 only


Question: The three way handshake for TCP connection establishment is shown below.  Which of the following statements are TRUE?(S1) Loss of SYN + ACK from the server will not establish a connection(S2) Loss of ACK from the client cannot establish the connection(S3) The server moves LISTEN → SYN_RCVD → SYN_SENT → ESTABLISHED in the state machine on no packet loss (S4) The server moves LISTEN → SYN_RCVD → ESTABLISHED in the state machine on no packet loss.

Choices:
- S2 and S3 only
- S1 and S4
- S1 and S3
- S2 and S4


Question:
Consider the following statements regarding the slow start phase of the TCP congestion control algorithm. Note that cwnd stands for the TCP congestion window and MSS denotes the Maximum Segment Size.
  The cwnd increase by 2 MSS on every successful acknowledgement.  The cwnd approximately doubles on every successful acknowledgedment.  The cwnd increase by 1 MSS every round trip time.  The cwnd approximately doubles every round trip time.
Which one of the following is correct?

Choices:
- Only (ii) and (iii) are true
- Only (i) and (iii) are true
- Only (iv) is true
- Only (i) and (iv) are true


Question:
Consider a long-lived TCP session with an end-to-end bandwidth of 1 Gbps (= 109 bits-per-second). The session starts with a sequence number of 1234. The minimum time (in seconds, rounded to the closest integer) before this sequence number can be used again is _______ .

Note - This was Numerical Type question.

Choices:
- 34
- 4.30
- 43
- None of these


Question: Match the following:

Choices:
- P-III, Q-IV, R-II, S-I
- P-II, Q-I, R-IV, S-III
- P-IV, Q-I, R-II, S-III
- P-IV, Q-I, R-III, S-II


Question: Which of the following layer of OSI Reference model is also called end-to-end layer ?

Choices:
- Network layer
- Data layer
- Session layer
- transport layer


Question: What is the maximum number of characters (7 bits + parity ) that can be transmitted in a second on a 19.2 kbps line. This asynchronous transmission requires 1 start bit and 1 stop bit.

Choices:
- 192
- 240
- 1920
- 1966


Question: Which of the following is not provided as a service in cloud computing?

Choices:
- Infrastructure as a service
- Architecture as a service
- Software as a service
- Platform as a service


Question: The encoding technique used to transmit the signal in giga ethernet technology over fiber optic medium is

Choices:
- Differential Manchester encoding
- Non return to zero
- 4B/5B  encoding
- 8B/10B encoding


Question: The network protocol which is used to get MAC address of a node by providing IP address is

Choices:
- SMTP
- ARP
- RIP
- BOOTP


Question: In which layer of network architecture, the secured socket layer (SSL) is used?

Choices:
- physical layer
- session layer
- application layer
- presentation layer


Question: The hamming distance between the octets of 0xAA and 0x55 is

Choices:
- 7
- 5
- 8
- 6


Question: Lightweight Directory Access protocol is used for

Choices:
- Routing the packets
- Authentication
- obtaining IP address
- domain name resolving


Question: Which of these is not a feature of WAP 2.0

Choices:
- Push and Pull Model
- Interface to a storage device
- Multimedia messaging
- Hashing


Question: Which one of the following is used to compute cyclomatic complexity?

Choices:
- The number of regions – 1
- E – N + 1, where E is the number of flow graph edges and N is the number of flow graph nodes.
- P – 1, where P is the number of predicate nodes in the flow graph G.
- P + 1, where P is the number of predicate nodes in the flow graph G.


Question:
Consider the following statements S1 and S2:
S1 : A hard handover is one in which the channel in the source cell is retained and used for a while in parallel with the channel in the target cell.
S2 : A soft handover is one in which the channel in the source cell is released and only then the channel in the target cell is engaged.

Choices:
- S1 is true and S2 is not true.
- S1 is not true and S2 is true.
- Both S1 and S2 are true.
- Both S1 and S2 are not true.


Question: Encrypt the Message “HELLO MY DEARZ” using Transposition Cipher with

Choices:
- HLLEO YM AEDRZ
- EHOLL ZYM RAED
- ELHL MDOY AZER
- ELHL DOMY ZAER


Question: In TCP, a unique sequence number is assigned to each

Choices:
- byte
- word
- segment
- message


Question: A host is connected to a Department network which is part of a University network. The University network, in turn, is part of the Internet. The largest network in which the Ethernet address of the host is unique is:

Choices:
- the subnet to which the host belongs
- the Department network
- the University network
- the Internet


Question: A subnet has been assigned a subnet mask of 255.255.255.192. What is the maximum number of hosts that can belong to this subnet?

Choices:
- 14
- 30
- 62
- 126


Question: In the network 200.10.11.144/27, the fourth octet (in decimal) of the last IP address of the network which can be assigned to a host is ________

Choices:
- 158
- 255
- 222
- 223


Question: A computing architecture, which allows the user to use computers from multiple administrative domains to reach a common goal is called as

Choices:
- Grid Computing
- Neutral Networks
- Parallel Processing
- Cluster Computing


Question: If the frame buffer has 8 bits per pixel and 8 bits are allocated for each of the R, G, B components, what would be the size of the lookup table?

Choices:
- 24 bytes
- 1024 bytes
- 768 bytes
- 256 bytes


Question:
Which of the following statements are true ?
(a) The fragmentation fields in the base header section of IPv4 have moved to the fragmentation extension header in IPv6.
(b) The authentication extension header is new in IPv6.
(c) The record route option is not implemented in IPv6.

Choices:
- (a) and (b) Only
- (b) and (c) Only
- (a) and (c) Only
- (a), (b) and (c)


Question: Range of IP Address from 224.0.0.0 to 239.255.255.255 are

Choices:
- Reserved for loopback
- Reserved for broadcast
- Used for multicast packets
- Reserved for future addressing


Question: The network 198.78.41.0 is a

Choices:
- Class A network
- Class B network
- Class C network
- Class D network


Question: What percentage(%) of the IPv4, IP address space do all class C addresses consume?

Choices:
- 12.5%
- 25%
- 37.5%
- 50%


Question: The default subnet mask for a class B network can be

Choices:
- 255.255.255.0
- 255.0.0.0
- 255.255.192.0
- 255.255.0.0


Question:
Consider the following routing table at an IP router  For each IP address in Group-I identify the correct choice of the next hop from Group-II using the entries from the routing table above.   List-I               List-II
A. 128.96.171.92     1. Interface 0
B. 128.96.167.151    2. Interface 1
C. 128.96.163.121    3. R2
D. 128.96.165.121    4. R3
                     5. R4
Codes:
     A B C D
(a)  1 3 5 4
(b)  1 4 2 5
(c)  2 3 4 5
(d)  2 3 5 4

Choices:
- a
- b
- c
- d


Question: In class B if subnet mask is 255.192.0.0 Total Number of networks than can be joined

Choices:
- 32
- 64
- 16
- None of the Above


Question: If block contains 32 IP address which of the following is first address of the block ?

Choices:
- 10.0.0.5
- 10.0.0.16
- 10.0.0.68
- 10.0.0.160


Question: Which of the following IP address can be used in WAN?

Choices:
- 10.0.0.1
- 172.16.0.10
- 15.1.5.6
- None


Question: Consider an uncompressed stereo audio signal of CD quality which is sampled at 44.1 kHz and quantized using 16 bits. What is required storage space if a compression ratio of 0.5 is achieved for 10 seconds of this audio?

Choices:
- 172 KB
- 430 KB
- 860 KB
- 1720 KB


Question: An example of poly-alphabetic substitution is

Choices:
- P-box
- S-box
- Caesar cipher
- Vigenere cipher


Question: A public key encryption system

Choices:
- allows anyone to decode the transmissions
- allows only the correct sender to decode the data
- allows only the correct receiver to decode the data
- does not encode the data before transmitting it


Question: A message "COMPUTERNETWORK" encrypted (ignore quotes) using columnar transposition cipher with a key "LAYER". The encrypted message is :

Choices:
- CTTOEWMROPNRUEK
- MROUEKCTTPNROEW
- OEWPNRCTTUEKMRO
- UEKPNRMROOEWCTT


Question: The standard for certificates used on internet is

Choices:
- X.25
- X.301
- X.409
- X.509


Question: Hashed message is signed by a sender using

Choices:
- his public key
- his private key
- receiver’s public key
- receiver’s private key


Question: How many distinct stages are there in DES algorithm, which is parameterized by a 56-bit key?

Choices:
- 16
- 17
- 18
- 19


Question: Which one of the following is true for asymmetric-key cryptography?

Choices:
- Private key is kept by the receiver and public key is announced to the public.
- Public key is kept by the receiver and private key is announced to the public.
- Both private key and public key are kept by the receiver.
- Both private key and public key are announced to the public.


Question: Avalanche effect in cryptography

Choices:
- Is desirable property of cryptographic algorithm
- Is undesirable property of cryptographic algorithm
- Has no effect on encryption algorithm
- None of the above


Question: Which of the following assertions is FALSE about the Internet Protocol (IP) ?

Choices:
- It is possible for a computer to have multiple IP addresses
- IP packets from the same source to the same destination can take different routes in the network
- IP ensures that a packet is discarded if it is unable to reach its destination within a given number of hops
- The packet source cannot set the route of an outgoing packets; the route is determined only by the routing tables in the routers on the way


Question: Routers forward a packet using forwarding table entries.  The network address of incoming packet may match multiple entries.  How routers resolve this?

Choices:
- Forward it the router whose entry matches with the longest prefix of incoming packet
- Forward the packet to all routers whose network addresses match.
- Discard the packet.
- Forward it the router whose entry matches with the longest suffix of incoming packet


Question:
Consider the following routing table of a router.PrefixNext Hop192.24.0.0/18D192.24.12.0/22B
Consider the following three IP addresses.Prefix192.24.0.0/18192.24.12.0/22192.24.54.0
How are the packets with above three destination IP addresses are forwarded?

Choices:
- 1->D, 2->B, 3->B
- 1->D, 2->B, 3->D
- 1->B, 2->D, 3->D
- 1->D, 2->D, 3->D


Question: Which one of the following fields of an IP header is NOT modified by a typical IP router?

Choices:
- Checksum
- Source address
- Time to Live (TTL)
- Length


Question: Advanced Encryption Standard (AES) is based on

Choices:
- Asymmetric key algorithm
- Symmetric key algorithm
- Public key algorithm
- Key exchange


Question: Optical fiber uses reflection to guide light through a channel, in which angle of incidence is ________ the critical angle.

Choices:
- equal to
- less than
- greater than
- less than or equal to


Question: Assume that source S and destination D are connected through two intermediate routers labeled R. Determine how many times each packet has to visit the network layer and the data link layer during a transmission from S to D.

Choices:
- Network layer – 4 times and Data link layer – 4 times
- Network layer – 4 times and Data link layer – 3 times
- Network layer – 4 times and Data link layer – 6 times
- Network layer – 2 times and Data link layer – 6 times


Question: Consider a source computer(S) transmitting a file of size 106 bits to a destination computer(D)over a network of two routers (R1 and R2) and three links(L1, L2, and L3). L1connects S to R1; L2 connects R1 to R2; and L3 connects R2 to D.Let each link be of length 100 km. Assume signals travel over each link at a speed of 108 meters per second.Assume that the link bandwidth on each link is 1Mbps. Let the file be broken down into 1000 packets each of size 1000 bits. Find the total sum of transmission and propagation delays in transmitting the file from S to D?

Choices:
- 1005 ms
- 1010 ms
- 3000 ms
- 3003 ms


Question:
An IP machine Q has a path to another IP machine H via three IP routers R1, R2, and R3.
Q—R1—R2—R3—H
H acts as an HTTP server, and Q connects to H via HTTP and downloads a file. Session layer encryption is used, with DES as the shared key encryption protocol. Consider the following four pieces of information:
[I1] The URL of the file downloaded by Q
[I2] The TCP port numbers at Q and H
[I3] The IP addresses of Q and H
[I4] The link layer addresses of Q and H
Which of I1, I2, I3, and I4 can an intruder learn through sniffing at R2 alone?

Choices:
- Only I1 and I2
- Only I1
- Only I2 and I3
- Only I3 and I4


Question: Which one of the following is TRUE about interior Gateway routing protocols - Routing Information Protocol (RIP) and Open Shortest Path First (OSPF)

Choices:
- RIP uses distance vector routing and OSPF uses link state routing
- OSPF uses distance vector routing and RIP uses link state routing
- Both RIP and OSPF use link state routing
- Both RIP and OSPF use distance vector routing


Question:
Consider the following three statements about link state and distance vector routing protocols, for a large network with 500 network nodes and 4000 links.
[S1] The computational overhead in link state protocols
     is higher than in distance vector protocols.
[S2] A distance vector protocol (with split horizon)
     avoids persistent routing loops, but not a link
     state protocol.
[S3] After a topology change, a link state protocol
     will converge faster than a distance vector
     protocol.
Which one of the following is correct about S1, S2, and S3 ?

Choices:
- S1, S2, and S3 are all true.
- S1, S2, and S3 are all false.
- S1 and S2 are true, but S3 is false
- S1 and S3 are true, but S2 is false


Question: For which one of the following reasons does Internet Protocol (IP) use the timeto- live (TTL) field in the IP datagram header

Choices:
- Ensure packets reach destination within that time
- Discard packets that reach later than that time
- Prevent packets from looping indefinitely
- Limit the time for which a packet gets queued in intermediate routers.


Question: Consider a network with 6 routers R1 to R6 connected with links having weights as shown in the following diagram:    All the routers use the distance vector based routing algorithm to update their routing tables. Each router starts with its routing table initialized to contain an entry for each neighbour with the weight of the respective connecting link. After all the routing tables stabilize, how many links in the network will never be used for carrying any data?

Choices:
- 4
- 3
- 2
- 1


Question: One of the header fields in an IP datagram is the Time to Live(TTL)field.Which of the following statements best explains the need for this field?

Choices:
- It can be used to prioritize packets
- It can be used to reduce delays
- It can be used to optimize throughput
- It can be used to prevent packet looping


Question:
Consider the same data as given in previous question.

After the update in the previous question, the link N1-N2 goes down. N2 will reflect this change immediately in its distance vector as cost, infinite. After the NEXT ROUND of update, what will be cost to N1 in the distance vector of N3?

Choices:
- 3
- 9
- 10
- Infinite


Question: In an IPv4 datagram, the M bit is 0, the value of HLEN is 10, the value of total length is 400 and the fragment offset value is 300. The position of the datagram, the sequence numbers of the first and the last bytes of the payload, respectively are

Choices:
- Last fragment, 2400 and 2789
- First fragment, 2400 and 2759
- Last fragment, 2400 and 2759
- Middle fragment, 300 and 689


Question: In class C , if subnet mask is 255.255.255.224 then calculates number of subnet?

Choices:
- 6
- 8
- 4
- None of the Above


Question: If a Company require 60 hosts then What is the best possible subnet mask?

Choices:
- 255.255.255.0
- 255.255.255.192
- 255.255.225.224
- 225.225.255.240


Question: A serial transmission Ti uses 8 information bits, 2 start bits, 1 stop bit and 1 parity bit for each character. A synchronous transmission T2 uses 3 eight bit sync characters followed by 30 eight bit information characters. If the bit rate is 1200 bits/second in both cases, what are the transfer rates of Ti and T2?

Choices:
- 100 characters/sec, 153 characters/sec
- 80 characters/sec, 136 characters/sec
- 100 characters/sec, 136 characters/sec
- 80 characters/sec, 153 characters/sec


Question: Which one of the following statements is FALSE?

Choices:
- HTTP runs over TCP
- HTTP describes the structure of web pages
- HTTP allows information to be stored in a URL
- HTTP can be used to test the validity of a hypertext link


Question: Which one of the following statements is FALSE?

Choices:
- TCP guarantees a minimum communication rate
- TCP ensures in-order delivery
- TCP reacts to congestion by reducing sender window size
- TCP employs retransmission to compensate for packet loss


Question:
Since it is a network that uses switch, every packet goes through two links, one from source to switch and other from switch to destination.

Since there are 10000 bits and packet size is 5000, two packets are sent.  Transmission time for each packet is 5000 / 107 microseconds.

Two hosts are connected via a packet switch with 107 bits per second links. Each link has a propagation delay of 20 microseconds. The switch begins forwarding a packet 35 microseconds after it receives the same. If 10000 bits of data are to be transmitted between the two hosts using a packet size of 5000 bits, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in microseconds is _________.

Choices:
- 1075
- 1575
- 2220
- 2200


Question: Host A sends a UDP datagram containing 8880 bytes of user data to host B over an Ethernet LAN. Ethernet frames may carry data up to 1500 bytes (i.e. MTU = 1500 bytes). Size of UDP header is 8 bytes and size of IP header is 20 bytes. There is no option field in IP header. How may total number of IP fragments will be transmitted and what will be the contents of offset field in the last fragment?

Choices:
- 6 and 925
- 6 and 7400
- 7 and 1110
- 7 and 8880


Question: Which of the following is NOT true with respect to a transparent bridge and a router?

Choices:
- Both bridge and router selectively forward data packets
- A bridge uses IP addresses while a router uses MAC addresses
- A bridge builds up its routing table by inspecting incoming packets
- A router can connect between a LAN and a WAN


Question:
Choose the best matching between Group 1 and Group 2.
   Group-1   	  	  Group-2
 P. Data link          1. Ensures reliable transport of data
                           over a physical point-to-point link
 Q. Network layer      2. Encoder/decodes data for physical
                          transmission
 R. Transport layer    3. Allows end-to-end communication
                          between two processes
                       4. Routes data from one network
                          node to the next

Choices:
- P-1, Q-4, R-3
- P-2, Q-4, R-1
- P-2, Q-3, R-1
- P-1, Q-3, R-2


Question: In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is

Choices:
- Network layer and Routing
- Data Link Layer and Bit synchronization
- Transport layer and End-to-end process communication
- Medium Access Control sub-layer and Channel sharing


Question:
Match the following:

(P) SMTP     (1) Application layer
(Q) BGP      (2) Transport layer
(R) TCP      (3) Data link layer
(S) PPP      (4) Network layer
             (5) Physical layer

Choices:
- P – 2 Q – 1 R – 3 S – 5
- P – 1 Q – 4 R – 2 S – 3
- P – 1 Q – 4 R – 2 S – 5
- P – 2 Q – 4 R – 1 S – 3


Question: Which one of the following is not a client server application?

Choices:
- Internet chat
- Web browsing
- E-mail
- ping


Question: In a RSA cryptosystem, a participant A uses two prime numbers p=13 and q=11 to generate his public and private keys. If the public key of A is 37, then the private key of A is _____.

Choices:
- 13
- 35
- 17
- 11


Question:
S1- MD5 is vulnerable to the Birthday attack.
S2- traceroute uses the "Destination port unreachable" ICMP error message.
S3- 3DES is a type of Public Key Encryption Algorithm.
S4- IPv6 has a 40-byte fixed header size(without Options fields).

How many of the above statements are true?

Choices:
- 2
- 3
- 4
- None of these


Question: The total number of keys required for a set of n individuals to be able to communicate with each other using secret key and public key crypto-systems, respectively are:

Choices:
- n(n-1) and 2n
- 2n and ((n(n - 1))/2)
- ((n(n - 1))/2) and 2n
- ((n(n - 1))/2) and n


Question: The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are:

Choices:
- TCP, UDP, UDP and TCP
- UDP, TCP, TCP and UDP
- UDP, TCP, UDP and TCP
- TCP, UDP, TCP and UDP


Question: Which of the following transport layer protocols is used to support electronic mail?

Choices:
- SMTP
- IP
- TCP
- UDP


Question: Consider an instance of TCP’s Additive Increase Multiplicative Decrease (AIMD) algorithm where the window size at the start of the slow start phase is 2 MSS and the threshold at the start of the first transmission is 8 MSS. Assume that a timeout occurs during the fifth transmission. Find the congestion window size at the end of the tenth transmission.

Choices:
- 8 MSS
- 14 MSS
- 7 MSS
- 12 MSS


Question: A layer-4 firewall (a device that can look at all protocol headers up to the transport layer) CANNOT

Choices:
- block entire HTTP traffic during 9:00PM and 5 :0OAM
- block all ICMP traffic
- stop incoming traffic from a specific IP address but allow outgoing traffic to the same IP address
- block TCP traffic from a specific user on a multi-user system during 9:00PM and 5:00AM


Question: In serial communications employing 8 data bits, a parity bit and 2 stop bits, the minimum band rate required to sustain a transfer rate of 300 characters per second is

Choices:
- 2400 band
- 19200 band
- 4800 band
- 1200 band


Question: What will be the total minimum bandwidth of the channel required for 7 channels of 400 kHz bandwidth multiplexed together with each guard band of 20 kHz?

Choices:
- 2800 khz
- 2600 khz
- 3600 khz
- 2920 khz


Question: In Go–back 3 flow control protocol every 6th packet is lost. If we have to send 11 packets. How many transmissions will be needed ?

Choices:
- 10
- 17
- 12
- 9


Question: Which protocol will be used to automate the IP configuration mechanism which includes IP address, subnet mask, default gateway, and DNS information?

Choices:
- SMTP
- DHCP
- ARP
- TCP/IP


Question: Provide the best matching between the entries in the two columns given in the table below:

Choices:
- I-a, II-d, III-c, IV-b
- I-b, II-d, III-c, IV-a
- I-a, II-c, III-d, IV-b
- I-b, II-c, III-d, IV-a


Question: Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.

Choices:
- HTTP GET request, DNS query, TCP SYN
- DNS query, HTTP GET request, TCP SYN
- DNS query, TCP SYN, HTTP GET request
- TCP SYN, DNS query, HTTP GET request


Question: Which one of the following protocols is NOT used to resolve one form of address to another one?

Choices:
- DNS
- ARP
- DHCP
- RARP


Question: In a sliding window ARQ scheme, the transmitter\'s window size is N and the receiver\'s window size is M. The minimum number of distinct sequence numbers required to ensure correct operation of the ARQ scheme is

Choices:
- min (M, N)
- max (M, N)
- M + N
- MN


Question:
An organization requires a range of IP address to assign one to each of its 1500 computers. The organization has approached an Internet Service Provider (ISP) for this task. The ISP uses CIDR and serves the requests from the available IP address space 202.61.0.0/17. The ISP wants to assign an address space to the organization which will minimize the number of routing entries in the ISP’s router using route aggregation. Which of the following address spaces are potential candidates from which the ISP can allot any one of the organization ?

I. 202.61.84.0 / 21
II. 202.61.104.0 / 21
III. 202.61.64.0 / 21
IV. 202.61.144.0 / 21

Choices:
- I and II only
- II and III only
- III and IV only
- I and IV only


Question:
Consider the following statements about the functionality of an IP based router.

 I. A router does not modify the IP packets during forwarding.
 II. It is not necessary for a router to implement any routing protocol.
 III. A router should reassemble IP fragments if the MTU of the outgoing link is larger than the size of the incoming IP packet.

Which of the above statements is/are TRUE ?

Choices:
- I and II only
- I only
- II and III only
- II only


Question: In a classful addressing, first four bits in Class A IP address is

Choices:
- 1010
- 1100
- 1011
- 1110
- (A) , (B), (C) and (D) are wrong.


Question: Exponentiation is a heavily used operation in public key cryptography. Which of the following options is the tightest upper bound on the number of multiplications required to compute bn mod m,0≤b,n≤m ?

Choices:
- O(logn)
- O(√n)
- O(n/logn)
- O(n)


Question: Which are the two modes of IP security?

Choices:
- Transport and certificate
- Transport and tunnel
- Certificate and tunnel
- Preshared and transport


Question: The subnet mask for a particular network is 255.255.31.0. Which of the following pairs of IP addresses could belong to this network?

Choices:
- 172.57.88.62 and 172.56.87.23
- 10.35.28.2 and 10.35.29.4
- 191.203.31.87 and 191.234.31.88
- 128.8.129.43 and 128.8.161.55


Question: The broadcast address for IP network 172.16.0.0 with subnet mask 255.255.0.0 is

Choices:
- 172.16.0.255
- 172.16.255.255
- 255.255.255.255
- 172.255.255.255


Question: Which of the following is/are restriction(s) in classless addressing?

Choices:
- The number of addresses needs to be a power of 2.
- The mask needs to be included in the address to define the block.
- The starting address must be divisible by the number of addresses in the block.
- All of the above


Question: In a classful addressing, the IP addresses with 0 (zero) as network number :

Choices:
- refers to the current network
- refers to broadcast on the local network
- refers to broadcast on a distant network
- refers to loopback testing


Question:
In a class B subnet, we know the IP address of one host and the mask as given below:

IP address: 125.134.112.66
Mask: 255.255.224.0

What is the first address(Network address)?

Choices:
- 125.134.96.0
- 125.134.112.0
- 125.134.112.66
- 125.134.0.0


Question: Which one of the following socket API functions converts an unconnected active TCP socket into a passive socket.

Choices:
- connect
- bind
- listen
- accept


Question: Let the size of congestion window of a TCP connection be 32 KB when a timeout occurs. The round trip time of the connection is 100 msec and the maximum segment size used is 2 KB. The time taken (in msec) by the TCP connection to get back to 32 KB congestion window is _________.

Choices:
- 1100 to 1300
- 800 to 1000
- 1400 to 1600
- 1500 to 1700


Question: Which one of the following uses UDP as the transport protocol?

Choices:
- HTTP
- Telnet
- DNS
- SMTP


Question: In the slow start phase of the TCP congestion control algorithm, the size of the congestion window

Choices:
- does not increase
- increases linearly
- increases quadratically
- increases exponentially


Question: Which of the following system calls results in the sending of SYN packets?

Choices:
- socket
- bind
- listen
- connect


Question:
While opening a TCP connection, the initial sequence number is to be derived using a time-of-day(ToD) clock that keeps running even when the host is down. The low order 32 bits of the counter of the ToD clock is to be used for the initial sequence numbers. The clock counter increments once per millisecond. The maximum packet lifetime is given to be 64s.
Which one of the choices given below is closest to the minimum permissible rate at which sequence numbers used for packets of a connection can increase?

Choices:
- 0.015/s
- 0.064/s
- 0.135/s
- 0.327/s


Question: The subnet mask 255.255.255.192

Choices:
- extends the network portion to 16 bits
- extends the network portion to 26 bits
- extends the network portion to 36 bits
- has no effect on the network portion of an IP address


Question:
Consider the following two statements:
i. A hash function (these are often used for computing digital signatures) is an injective function.
A. encryption technique such as DES performs a permutation on the elements of its input alphabet.
Which one of the following options is valid for the above two statements?

Choices:
- Both are false
- Statement (i) is true and the other is false
- Statement (ii) is true and the other is false
- Both are true


Question: Consider that B wants to send a message m that is digitally signed to A. Let the pair of private and public keys for A and B be denoted  represent the operation of encrypting m with a key Kx and H(m) represent the message digest. Which one of the following indicates the CORRECT way of sending the message m along with the digital signature to A?

Choices:
- A
- B
- C
- D


Question: A sender is employing public key cryptography to send a secret message to a receiver. Which one of the following statements is TRUE?

Choices:
- Sender encrypts using receiver’s public key
- Sender encrypts using his own public key
- Receiver decrypts using sender’s public key
- Receiver decrypts using his own public key


Question: What percentage(%) of the IPv4, IP address space do all class C addresses consume?

Choices:
- 12.5%
- 25%
- 37.5%
- 50%


Question: The network 198.78.41.0 is a

Choices:
- Class A network
- Class B network
- Class C network
- Class D network


Question: Range of IP Address from 224.0.0.0 to 239.255.255.255 are

Choices:
- Reserved for loopback
- Reserved for broadcast
- Used for multicast packets
- Reserved for future addressing


Question:
Match the security protocols with the layers they are used in and choose the correct code - [Tex]\begin{array}{ll}
List-1 & List-2\\
A. TLS & 1. Physical Layer\\
B. WEP & 2. Link Layer\\
C. PGP & 3. Network Layer\\
D. IPsec & 4. Transport Layer\\
& 5. Application Layer\\
\end{array}[/Tex]Codes- [Tex] \begin{array}{lllll}
& A & B & C & D\\
(a) & 2 & 5 & 1 & 3\\
(b) & 5 & 2 & 3 & 2\\
(c) & 4 & 2 & 5 & 3\\
(d) & 5 & 2 & 4 & 3\\
\end{array}[/Tex]

Choices:
- (d)
- (c)
- (b)
- (a)


Question: A T-switch is used to

Choices:
- Control how messages are passed between computers
- Echo every character that is received
- Transmit characters one at a time
- Rearrange the connections between computing equipments


Question: The IEEE standard for WiMax technology is

Choices:
- IEEE 802.16
- IEEE 802.36
- IEEE 812.16
- IEEE 806.16


Question: Data is transmitted continuously at 2.048 Mbps rate for 10 hours and received 512 bits errors. What is the bit error rate?

Choices:
- 6.9 e-9
- 6.9 e-6
- 69 e-9
- 4 e-9


Question: In networking, UTP stands for

Choices:
- Unshielded T-connector port
- Unshielded twisted pair
- Unshielded terminating pair
- Unshielded transmission process


Question: Phase transition for each bit are used in

Choices:
- Amplitude modulation
- Carrier modulation
- Manchester encoding
- NRZ encoding


Question: An email contains a textual birthday greeting, a picture of a cake and a song. The order is not important. What is the content-type?

Choices:
- Multipart/mixed
- Multipart/parallel
- Multipart/digest
- Multipart/alternative


Question: A firewall is to be configured to allow hosts in a private network to freely open TCP connections and send packets on open connections. However, it will only allow external hosts to send packets on existing open TCP connections or connections that are being opened (by internal hosts) but not allow them to open TCP connections to hosts in the private network. To achieve this the minimum capability of the firewall should be that of

Choices:
- A combinational circuit
- A finite automaton
- A pushdown automaton with one stack
- A pushdown automaton with two stacks


Question: The default subnet mask for a class B network can be

Choices:
- 255.255.255.0
- 255.0.0.0
- 255.255.192.0
- 255.255.0.0


Question: How many bytes of data can be sent in 15 seconds over a serial link with baud rate of 9600 in asynchronous mode with odd parity and two stop bits in the frame?

Choices:
- 10,000 bytes
- 12,000 bytes
- 15,000 bytes
- 27,000 bytes


Question: Anarkali digitally signs a message and sends it to Salim. Verification of the signature by Salim requires

Choices:
- Anarkali’s public key.
- Salim’s public key.
- Salim’s private key.
- Anarkali’s private key.


Question: Using public key cryptography, X adds a digital signature σ to a message M, encrypts (M,σ) and sends it to Y, where it is decrypted. Which one of the following sequence of keys is used for operations?

Choices:
- Encryption : X’s private key followed by Y’s private key. Decryption : X’s public key followed by Y’s public key.
- Encryption : X’s private key followed by Y’s public key; Decryption : X’s public key followed by Y’s private key
- Encryption : X’s private key followed by Y’s public key; Decryption : Y’s private key followed by X’s public key.
- Encryption : X’s public key followed by Y’s private key; Decryption : Y’s public key followed by X’s private key.


Question: If there are N people in the world and are using secret key encryption/decryption for privacy purpose, then number of secret keys required will be:

Choices:
- N
- (N - 1)
- N (N - 1) / 2
- N (N + 1) / 2


Question: SHA-1 is a

Choices:
- encryption algorithm
- decryption algorithm
- key exchange algorithm
- message digest function


Question: The minimum positive integer p such that 3p modulo 17 = 1 is

Choices:
- 5
- 8
- 12
- 16


Question:
In cryptography, the following uses transposition ciphers and the keyword is LAYER. Encrypt the following message. (Spaces are omitted during encryption)
WELCOME TO NETWORK SECURITY !

Choices:
- WMEKREETSILTWETCOOCYONRU!
- EETSICOOCYWMEKRONRU!LTWET
- LTWETONRU!WMEKRCOOCYEETSI
- ONRU!COOCYLTWETEETSIWMEKR


Question: A Trojan horse is

Choices:
- A program that performs a legitimate function that is known to an operating system or its user and also has a hidden component that can be used for nefarious purposes like attacks on message security or impersonation.
- A piece of code that can attach itself to other programs in the system and spread to   other systems when programs are copied or transferred.
- A program that spreads to other computer systems by exploiting security holes like weaknesses in facilities for creation of remote processes
- All of the above


Question: Two computers C1 and C2 are configured as follows. C1 has IP address 203.197.2.53 and netmask 255.255.128.0. C2 has IP address 203.197.75.201 and netmask 255.255.192.0. which one of the following statements is true?

Choices:
- C1 and C2 both assume they are on the same network
- C2 assumes C1 is on same network, but C1 assumes C2 is on a different network
- C1 assumes C2 is on same network, but C2 assumes C1 is on a different network
- C1 and C2 both assume they are on different networks.


Question:
Classless Inter-domain Routing (CIDR) receives a packet with address 131.23.151.76. The router’s routing table has the following entries:
Prefix           Output Interface Identifier
131.16.0.0/12              3
131.28.0.0/14              5
131.19.0.0/16              2
131.22.0.0/15              1
The identifier of the output interface on which this packet will be forwarded is ______.

Choices:
- 1
- 2
- 3
- 5


Question: Consider the data given in above question. Suppose the weights of all unused links in the previous question are changed to 2 and the distance vector algorithm is used again until all routing tables stabilize. How many links will now remain unused?

Choices:
- 0
- 1
- 2
- 3


Question:
Consider a network with five nodes, N1 to N5, as shown below.

The network uses a Distance Vector Routing protocol. Once the routes have stabilized, the distance vectors at different nodes are as following.

N1: (0, 1, 7, 8, 4)
N2: (1, 0, 6, 7, 3)
N3: (7, 6, 0, 2, 6)
N4: (8, 7, 2, 0, 4)
N5: (4, 3, 6, 4, 0)

Each distance vector is the distance of the best known path at the instance to nodes, N1 to N5, where the distance to itself is 0. Also, all links are symmetric and the cost is identical in both directions. In each round, all nodes exchange their distance vectors with their respective neighbors. Then all nodes update their distance vectors. In between two rounds, any change in cost of a link will cause the two incident nodes to change only that entry in their distance vectors. 52. The cost of link N2-N3 reduces to 2(in both directions). After the next round of updates, what will be the new distance vector at node, N3.

Choices:
- (3, 2, 0, 2, 5)
- (3, 2, 0, 2, 6)
- (7, 2, 0, 2, 5)
- (7, 2, 0, 2, 6)


Question: Suppose that everyone in a group of N people wants to communicate secretly with the N–1 others using symmetric key cryptographic system. The communication between any two persons should not be decodable by the others in the group. The number of keys required in the system as a whole to satisfy the confidentiality requirement is

Choices:
- 2N
- N(N – 1)
- N(N – 1)/2
- (N – 1)2


Question: A Trojan horse is

Choices:
- A program that performs a legitimate function that is known to an operating system or its user and also has a hidden component that can be used for nefarious purposes like attacks on message security or impersonation.
- A piece of code that can attach itself to other programs in the system and spread to   other systems when programs are copied or transferred.
- A program that spreads to other computer systems by exploiting security holes like weaknesses in facilities for creation of remote processes
- All of the above


Question:
Consider the following routing table at an IP router  For each IP address in Group-I identify the correct choice of the next hop from Group-II using the entries from the routing table above.   List-I               List-II
A. 128.96.171.92     1. Interface 0
B. 128.96.167.151    2. Interface 1
C. 128.96.163.121    3. R2
D. 128.96.165.121    4. R3
                     5. R4
Codes:
     A B C D
(a)  1 3 5 4
(b)  1 4 2 5
(c)  2 3 4 5
(d)  2 3 5 4

Choices:
- a
- b
- c
- d


Question: If block contains 32 IP address which of the following is first address of the block ?

Choices:
- 10.0.0.5
- 10.0.0.16
- 10.0.0.68
- 10.0.0.160


Question:
Which of the following are used to generate a message digest by the network security protocols?
(P) RSA
(Q) SHA-1
(R) DES
(S) MD5

Choices:
- P and R only
- Q and R only
- Q and S only
- R and S only


Question:
In the RSA public key cryptosystem, the private and public keys are (e, n) and (d, n) respectively, where n = p*q and p and q are large primes. Besides, n is public and p and q are private. Let M be an integer such that 0 < M < n and f(n) = (p- 1)(q-1). Now consider the following equations.
I.  M’= Me mod n
    M = (M’)d mod n

II.  ed ≡ 1 mod n

III. ed ≡ 1 mod f(n)

IV. M’= Me mod f(n)
    M = (M’)d mod f(n)

Which of the above equations correctly represent RSA cryptosystem?

Choices:
- I and II
- I and III
- II and IV
- III and IV


Question: Using public key cryptography, X adds a digital signature [Tex]\\sigma[/Tex] to message M, encrypts < M, [Tex]\\sigma[/Tex] >, and sends it to Y, where it is decrypted. Which one of the following sequences of keys is used for the operations?

Choices:
- Encryption: X’s private key followed by Y’s private key; Decryption: X’s public key followed by Y’s public key
- Encryption: X’s private key followed by Y’s public key; Decryption: X’s public key followed by Y’s private key
- Encryption: X’s public key followed by Y’s private key; Decryption: Y’s public key followed by X’s private key
- Encryption: X’s private key followed by Y’s public key; Decryption: Y’s private key followed by X’s public key


Question: How many bits internet address is assigned to each host on a TCP/IP internet which is used in all communication with the host?

Choices:
- 16 bits
- 32 bits
- 48 bits
- 64 bits


Question: The DNS maps the IP address to

Choices:
- A binary address as strings
- An alphanumeric address
- A hierarchy of domain names
- A hexadecimal address


Question: The address of a class B host is to be split into subnets with a 6 - bit subnet number. What is the maximum number of subnets and maximum number of hosts in each subnet?

Choices:
- 62 subnets and 1022 hosts
- 64 subnets and 1024 hosts
- 62 subnets and 254 hosts
- 64 subnets and 256 hosts


Question: An Internet Service Provider (ISP) has the following chunk of CIDR-based IP addresses available with it: 245.248.128.0/20. The ISP wants to give half of this chunk of addresses to Organization A, and a quarter to Organization B, while retaining the remaining with itself. Which of the following is a valid allocation of addresses to A and B?

Choices:
- 245.248.136.0/21 and 245.248.128.0/22
- 245.248.128.0/21 and 245.248.128.0/22
- 245.248.132.0/22 and 245.248.132.0/21
- 245.248.136.0/24 and 245.248.132.0/21


Question: In the IPv4 addressing format, the number of networks allowed under Class C addresses is

Choices:
- 220
- 224
- 214
- 221


Question:
A packet addressed to 128.48.64.0 came to a router having routing table as follows.

Which interface will it be forwarded to ?

Choices:
- A
- B
- C
- D


Question:
Host X has IP address 192.168.1.97 and is connected through two routers R1 and R2 to another host Y with IP address 192.168.1.80. Router R1 has IP addresses 192.168.1.135 and 192.168.1.110. R2 has IP addresses 192.168.1.67 and 192.168.1.155. The netmask used in the network is 255.255.255.224.

Which IP address should X configure its gateway as?

Choices:
- 192.168.1.67
- 192.168.1.110
- 192.168.1.135
- 192.168.1.155


Question: Host X has IP address 192.168.1.97 and is connected through two routers R1 and R2 to another host Y with IP address 192.168.1.80. Router R1 has IP addresses 192.168.1.135 and 192.168.1.110. R2 has IP addresses 192.168.1.67 and 192.168.1.155. The netmask used in the network is 255.255.255.224. Given the information above, how many distinct subnets are guaranteed to already exist in the network?

Choices:
- 6
- 3
- 2
- 1


Question: In class B if subnet mask is 255.192.0.0 Total Number of networks than can be joined

Choices:
- 32
- 64
- 16
- None of the Above


Question: The subnet mask for a particular network is 255.255.31.0. Which of the following pairs of IP addresses could belong to this network?

Choices:
- 172.57.88.62 and 172.56.87.233
- 10.35.28.2 and 10.35.29.4
- 191.203.31.87 and 191.234.31.88
- 128.8.129.43 and 128.8.161.55


Question: If a class B network on the Internet has a subnet mask of 255.255.248.0, what is the maximum number of hosts per subnet?

Choices:
- 1022
- 1023
- 2046
- 2047


Question: Suppose computers A and B have IP addresses 10.105.1.113 and 10.105.1.91 respectively and they both use the same netmask N. Which of the values of N given below should not be used if A and B should belong to the same network?

Choices:
- 255.255.255.0
- 255.255.255.128
- 255.255.255.192
- 255.255.255.224


Question: An Internet Service Provider (ISP) has the following chunk of CIDR-based IP addresses available with it: 245.248.128.0/20. The ISP wants to give half of this chunk of addresses to Organization A, and a quarter to Organization B, while retaining the remaining with itself. Which of the following is a valid allocation of addresses to A and B?

Choices:
- 245.248.136.0/21 and 245.248.128.0/22
- 245.248.128.0/21 and 245.248.128.0/22
- 245.248.132.0/22 and 245.248.132.0/21
- 245.248.136.0/24 and 245.248.132.0/21


Question: An Internet Service Provider(ISP) has the following chunk of CIDR-based IP addresses available with it:245.248.128.0/20. The ISP wants to give half of this chunk of addresses to Organization A, and a quarter to Organization B, while retaining the remaining with itself. Which of the following is a valid allocation of addresses to A and B?

Choices:
- 245.248.136.0/21 and 245.248.128.0/22
- 245.248.128.0/21 and 245.248.128.0/22
- 245.248.132.0/22 and 245.248.132.0/21
- 245.248.136.0/22 and 245.248.132.0/21


Question: Which of the following is public IP address ?

Choices:
- 10.15.14.12
- 192.168.52.62
- 172.32.1.1
- None of the Above


Question: If subnet mask 255.255.255.224, which of the following will be Direct Broadcast address ?

Choices:
- 202.15.19.127
- 202.15.19.63
- Both a and b
- None of the Above


Question: If Direct Broadcast address is 201.15.16.31, which of the following can be subnet mask?

Choices:
- 255.255.255.240
- 255.255.255.248
- 255.255.255.252
- All of the Above


Question: If Direct Broadcast Address of subnet is 201.15.16.31. Which of the following will be subnet mask ?

Choices:
- 255.255.255.239
- 255.255.255.192
- 255.255.255.198
- None Of the Above


Question: Which of the following can be used as both Source and Destination IP?

Choices:
- 198.168.1.255
- 10.0.0.1
- 127.0.0.1
- 255.255.255.255


Question: In the IPv4 addressing format, the number of networks allowed under Class C addresses is

Choices:
- 2^14
- 2^7
- 2^21
- 2^24


Question: Which of the following IP address can be used in WAN?

Choices:
- 10.0.0.1
- 172.16.0.10
- 15.1.5.6
- None


Question: The address of a class B host is to be split into subnets with a 6-bit subnet number. What is the maximum number of subnets and the maximum number of hosts in each subnet?

Choices:
- 62 subnets and 262142 hosts.
- 64 subnets and 262142 hosts.
- 62 subnets and 1022 hosts.
- 64 subnets and 1024 hosts.


Question:
In cryptography, the following uses transposition ciphers and the keyword is LAYER. Encrypt the following message. (Spaces are omitted during encryption)
WELCOME TO NETWORK SECURITY !

Choices:
- WMEKREETSILTWETCOOCYONRU!
- EETSICOOCYWMEKRONRU!LTWET
- LTWETONRU!WMEKRCOOCYEETSI
- ONRU!COOCYLTWETEETSIWMEKR


Question: The minimum positive integer p such that 3p modulo 17 = 1 is

Choices:
- 5
- 8
- 12
- 16


Question: SHA-1 is a

Choices:
- encryption algorithm
- decryption algorithm
- key exchange algorithm
- message digest function


Question: A 1Mbps satellite link connects two ground stations. The altitude of the satellite is 36,504 km and speed of the signal is 3 × 108 m/s. What should be the packet size for a channel utilization of 25% for a satellite link using go-back-127 sliding window protocol? Assume that the acknowledgment packets are negligible in size and that there are no errors during communication.

Choices:
- 120 bytes
- 60 bytes
- 240 bytes
- 90 bytes


Question: The minimum frame size required for a CSMA/CD based computer network running at 1 Gbps on a 200m cable with a link speed of 2 × 108m/s is

Choices:
- 125 bytes
- 250 bytes
- 500 bytes
- None of these


Question:
Data transmitted on a link uses the following 2D parity scheme for error detection:
Each sequence of 28 bits is arranged in a 4×7 matrix (rows r0 through r3, and columns d7 through d1) and is padded with a column d0 and row r4 of parity bits computed using the Even parity scheme. Each bit of column d0 (respectively, row r4) gives the parity of the corresponding row (respectively, column). These 40 bits are transmitted over the data link.
The table shows data received by a receiver and has n corrupted bits. What is the minimum possible value of n?

Choices:
- 1
- 2
- 3
- 4


Question: Suppose that the one-way propagation delay for a 100 Mbps Ethernet having 48-bit jamming signal is 1.04 micro-seconds. The minimum frame size in bits is:

Choices:
- 112
- 160
- 208
- 256


Question: Which of the following statement is False about the efficiency of the given channel?

Choices:
- If we want to send big packets on the channel, then Stop and Wait is good choice.
- If length of packet increases, efficiency of channel also increases.
- Distance between sender and receiver is directly proportional to efficiency of channel.
- Efficient might be less if capacity of channel is high.


Question:
Consider a simple communication system where multiple nodes are connected by a shared broadcast medium (like Ethernet or wireless). The nodes in the system use the following carrier-sense the medium access protocol. A node that receives a packet to transmit will carrier-sense the medium for 5 units of time. If the node does not detect any other transmission in this duration, it starts transmitting its packet in the next time unit. If the node detects another transmission, it waits until this other transmission finishes, and then begins to carrier-sense for 5 time units again. Once they start to transmit, nodes do not perform any collision detection and continue transmission even if a collision occurs. All transmissions last for 20 units of time. Assume that the transmission signal travels at the speed of 10 meters per unit time in the medium.

Assume that the system has two nodes P and Q, located at a distance d meters from each other. P starts transmitting a packet at time t = 0 after successfully completing its carrier-sense phase. Node Q has a packet to transmit at time t = 0 and begins to carrier-sense the medium.

The maximum distance d (in meters, rounded to the closest integer) that allows Q to successfully avoid a collision between its proposed transmission and P’s on going transmission is _______ .

Note -This was Numerical Type question.

Choices:
- 50
- 150
- 20
- 60


Question: Which of the following devices takes data sent from one network device and forwards it to the destination node based on MAC address ?

Choices:
- Hub
- Modem
- Switch
- Gateway


Question: The number of bits used for addressing in Gigabit Ethernet is __________.

Choices:
- 32 bit
- 48 bit
- 64 bit
- 128 bit


Question: Suppose we want to download text documents at the rate of 100 pages per second. Assume that a page consists of an average of 24 lines with 80 characters in each line. What is the required bit rate of the channel?

Choices:
- 192 kbps
- 512 kbps
- 1.248 Mbps
- 1.536 Mbps