Hi friends, how r u? As my promise, “I will come with Network Exam Question part-3″ – so here I’m presenting computer Network question answer (part 3).
Computer Network Question Answer – (Part 3)
1. What is ICMP?
Answer
ICMP is Internet Control Message Protocol, a network layer protocol of the TCP/IP suite used by hosts and gateways to send notification of datagram problems back to the sender. It uses the echo test / reply to test whether a destination is reachable and responding. It also handles both control and error messages.
2. What is Brouter?
Answer
Hybrid devices that combine the features of both bridges and routers.
3. What is frame relay, in which layer it comes?
Answer
Frame relay is a packet switching technology. It will operate in the data link layer.
4. What is External Data Representation?
Answer
External Data Representation is a method of encoding data within an RPC message, used to ensure that the data is not system-dependent.
5. What is Bandwidth?
Answer
Every line has an upper limit and a lower limit on the frequency of signals it can carry. This limited range is called the bandwidth.
6. What protocol is used by DNS name servers?
Answer
DNS uses UDP for communication between servers. It is a better choice than TCP because of the improved speed a connectionless protocol offers. Of course, transmission reliability suffers with UDP.
7. What is the range of addresses in the classes of internet addresses?
Answer
Class A 0.0.0.0 – 127.255.255.255
Class B 128.0.0.0 – 191.255.255.255
Class C 192.0.0.0 – 223.255.255.255
Class D 224.0.0.0 – 239.255.255.255
Class E 240.0.0.0 – 247.255.255.255.
8. What are the important topologies for networks?
Answer
BUS topology:
In this each computer is directly connected to primary network cable in a single line.
Advantages:
Inexpensive, easy to install, simple to understand, easy to extend.
STAR topology:
In this all computers are connected using a central hub.
Advantages:
Can be inexpensive, easy to install and reconfigure and easy to trouble shoot physical problems.
RING topology:
In this all computers are connected in loop.
Advantages:
All computers have equal access to network media, installation can be simple, and signal does not degrade as much as in other topologies because each computer regenerates it.
9. Difference between bit rate and baud rate?
Answer
Bit rate is the number of bits transmitted during one second whereas baud rate refers to the number of signal units per second that are required to represent those bits.
baud rate = bit rate / N
where N is no-of-bits represented by each signal shift.
10. What is anonymous FTP and why would you use it?
Answer
Anonymous FTP enables users to connect to a host without using a valid login and password. Usually, anonymous FTP uses a login called anonymous or guest, with the password usually requesting the user’s ID for tracking purposes only. Anonymous FTP is used to enable a large number of users to access files on the host without having to go to the trouble of setting up logins for them all. Anonymous FTP systems usually have strict controls over the areas an anonymous user can access.
11. What is the difference between an unspecified passive open and a fully specified passive open?
Answer
An unspecified passive open has the server waiting for a connection request from a client.
A fully specified passive open has the server waiting for a connection from a specific client.
12. What is virtual path?
Answer
Along any transmission path from a given source to a given destination, a group of virtual circuits can be grouped together into what is called path.
13. Explain the function of Transmission Control Block?
Answer
A TCB is a complex data structure that contains a considerable amount of information about each connection.
14. What is a DNS resource record?
Answer
A resource record is an entry in a name server’s database. There are several types of resource records used, including name-to-address resolution information. Resource records are maintained as ASCII files.
15. What is a pseudo tty?
Answer
A pseudo tty or false terminal enables external machines to connect through Telnet or rlogin. Without a pseudo tty, no connection can take place.
16. What is the Network Time Protocol?
Answer
A protocol that assures accurate local timekeeping with reference to radio and atomic clocks located on the Internet. This protocol is capable of synchronising distributed clocks within milliseconds over long time periods. It is defined in STD 12, RFC 1119.
17. What is mesh network?
Answer
A network in which there are multiple network links between computers to provide multiple paths for data to travel.
18. What is RAID?
Answer
A method for providing fault tolerance by using multiple hard disk drives.
19. What is a Management Information Base (MIB)?
Answer
A Management Information Base is part of every SNMP-managed device. Each SNMP agent has the MIB database that contains information about the device’s status, its performance, connections, and configuration. The MIB is queried by SNMP.
20. What is cladding?
Answer
A layer of a glass surrounding the center fiber of glass inside a fiber-optic cable.
21. What is subnet?
Answer
A generic term for section of a large networks usually separated by a bridge or router.
A gateway operates at the upper levels of the OSI model and translates information between two completely different network architectures or data formats.
22. What is point-to-point protocol?
Answer
A communications protocol used to connect computers to remote networking services including Internet service providers.
23. What are 10Base2, 10Base5 and 10BaseT Ethernet LANs ?
Answer
10Base2—An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with a contiguous cable segment length of 100 meters and a maximum of 2 segments
10Base5—An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling, with 5 continuous segments not exceeding 100 meters per segment.
10BaseT—An Ethernet term meaning a maximum transfer rate of 10 Megabits per second that uses baseband signaling and twisted pair cabling.
24. What are the possible ways of data exchange?
Answer
(i) Simplex
(ii) Half-duplex
(iii) Full-duplex.
25. What are the two types of transmission technology available?
Answer
(i) Broadcast
(ii) point-to-point.
26. How do I convert a numeric IP address like 192.18.97.39 into a hostname like java.sun.com?
Answer
String hostname = InetAddress.getByName(“192.18.97.39″).getHostName().
27. Where do you get updates on security?
Answer
This type of question is meant to see the interest of the candidate in keeping abreast in the field of network security. If the candidate puts up a blank face, it is time to call next candidate. One can specify “news alerts” or any website(s) s/he checks out for latest information about security.
28. If you need to encrypt and compress data for transmission, how would you achieve it?
Answer
The candidate may start explaining what is data encryption, how s/he would encrypt the data and then compress it for transmission. However, the actual answer would be to explain how to compress and then talk about encryption. Encrypting compressed data often leads to loss of data.
29. What factors would you consider before deploying a web intrusion detection system?
Answer
An open question, the interviewer is trying to assess the knowledge of candidate in different fields associated with web intrusion. These include: SSL; HTTP protocol; logging; alert mechanism; and signature update policies.
30. What is Cross site scripting?
Answer
Though the answer is straightforward, most candidates are unaware of the term. One of the most important security issues, cross scripting refers to phishing attempts by a website that employs a java script that leads to deploying a malware without the knowledge of user.
31. How does the HTTP handle state?
Answer
The answer is that HTTP cannot handle states. However, there is a hack. It employs use of cookies to handle the state.
32. In context of public key encryption, if you are using both signature and encryption features, what key will you use for encryption and which one will you use for signing?
Answer
Answer is simple. One would always sign using their key so the public key is used for encryption. Most of the candidates tend to name public key for both signing and encryption. They miss out the point that public key encryption also includes a private key.
33. What type of network do you use at home?
Answer
Again, this question is employed to assess the skills and networking background of candidates. “I don’t have a network at home but I have handled networks at so and so places” is better than saying “sorry, I don’t have a network at home”. The latter would send out a signal that the candidate never had exposure to networks.
34. What is Cross Site Request Forgery and how to defend against it?
Answer
The question can also be in two parts, in which case, candidates without knowledge of CSRF would get lost. If asked combined, candidates can guess that cross site request forgery is something that relates to malicious scripting with phishing intentions. The question may also be framed as “what is cross site request”. In this case, candidates cannot even guess that it is something malicious as the word ‘forgery’ is not there.
35. Name the port used by PING?
Answer
Always remember that PING does not use any port. As PING is based upon layer 3 protocol, it never uses any computer port. A simple variation of the question could be: Does PING use UDP? Or Does PING use TCP? Again remember that UDP and TCP are layer 4 protocols and PING has nothing to do with them.
36. Security Life Cycle?
Answer
It can be phrased in many ways: what comes first – vulnerability or threat? How do you design a system with some options given? The candidate needs to answer these questions using his/her own experience and opinions. The objective is how best the candidate can explain what you asked.
These are just some of the network security interview questions that are meant to give you an idea of how a security interview goes. If you wish to share your experience or wish to add anything, please feel free to share using comments box.
37. Define the meaning of an Authentication?
Answer
Well sir, an Authentication factor is a piece of information and process used to authenticate or verify the identity of a person or other entity requesting access under security constraints. In other word, it is a process of proving the identity of a computer or computer user. For users, it generally involves a user name and password. Computers usually pass a code that identifies that they are part of a network.
38. What is the sense of a fingerprint?
Answer
A fingerprint is an impression of the friction ridges on all parts of the finger. A friction ridge is a raised portion of the epidermis on the palmer (palm) or digits i.e. fingers and toes or plantar or sole skin, consisting of one or more connected ridge units of friction ridge skin. This is also known as Epidermal Ridges which is originated by the underlying interface between the dermal papillae of the dermis and the interpapillary (rete) pegs of the epidermis.
39. What a security mean in your sense?
Answer
A security is a fungible, negotiable instrument representing financial value. Securities are generally sorted out into debt securities such as banknotes, bonds and debentures and equity securities.
For example: common stocks and derivative contracts such as forwards, futures, options and swaps.
40. What is a Password?
Answer
A password is a secret word or string of characters that is used for authentication to prove identity or gain access to a resource. The password must be kept secret from those not allowed access.
For example: An access code is a type of password.
41. What is a Smart Card or Chip Card or Integrated Circuit Card (ICC)?
Answer
A Smart Card or Chip Card or Integrated Circuit Card (ICC) is any pocket-sized card with embedded integrated circuits which can process data. This implies that it can receive input which is processed by the way of the ICC applications and delivered as an output.
42. Finally, who is a hacker?
Answer
A hacker is a person who breaks into computers usually by gaining access to administrative controls. He uses to access the user id and password without taking the permission. As a result of this article, you will definitely going to show best performance in the interview.
43. What is ACID property in client server environment?
Answer
ACID is a term coined by Andrew Reuter in 1983, which stands for Atomicity, Consistence, Isolation and Durability.
ACID property is the basic property for transaction processing.
A – atomicity
C – consistency
I – isolation
D – durability.
44. What is meant by 2-Tier architecture in client server environment?
Answer
In 2-tier Client/Server systems, the application logic is either burried inside the user interface on the client or within the database on the server.
Example: File servers and Database servers with stored procedures.
45. What is meant by Transparency in client server environment?
Answer
Transparency really means hiding the network and its servers from the users and even the application programmers.
46. What is a Web server in client server environment?
Answer
This new model of Client/Server consists of thin, protable, “universal” clients that talk to superfat servers. In the simplet form, a web server returns documents when clients ask for them by name. The clients and server communicate using an RPC-like protocol called HTTP
47. What is a Database Server in client server environment?
Answer
With a database server, the client passes SQL requests as messages to the database server. The results of each SQL command are returned over the network. The server uses its own processing power to find the request data instead of passing all the records back to the client and then getting it find its own data. The result is a much more efficient use of distributed processing power. It is also known as SQL engine.
48. What are Super servers in client server environment?
Answer
These are fully-loaded machines which includes multiprocessors, high-speed disk arrays for intervive I/O and fault tolerant features.
49. What is Message Oriented Middleware (MOM) in client server environment?
Answer
MOM allows general purpose messages to be exchanged in a Client/Server system using message queues. Applications communicate over networks by simply putting messages in the queues and getting messages from queues. It typically provides a very simple high level APIs to its services.
MOM’s messaging and queuing allow clients and servers to communicate across a network without being linked by a private, dedicated, logical connection. The clients and server can run at different times. It is a post-office like metaphor.
50. What are the two types of OLTP in client server environment?
Answer
TP lite, based on stored procedures,
TP heavy, based on the TP monitors.
