Network Engineer Interview Questions and answers

In this post you will learn network administrator interview questions and answers. These questions from basic to advanced level interview questions.

1. What is Network?

A network is a set of devices connected by physical media links. It is used to share resources such as  data, printers,CD-ROM and exchanging files. The main purpose of the networking is to share information.

 2.What is firewall and how it is used?

A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by the filters, it is not allowed through. Firewall prevents a connection between two or multiple sources; it basically blocks any incoming or outgoing traffic.

3.  What type of authentication do you use for network access?

Knowledge of different types of authentication, an understanding of different security protocols

"Two-factor authentication is substantially more secure than single factor authentication. For sensitive information, I would definitely recommend an upgrade if you don't already use two-factor authentication. Biometrics are often the easiest for users, provided you already have the hardware. If not, a token is a great way to add security without spending a lot on hardware."

4. Difference Between workgroup and Domain?

With a Workgroup you have a collection of systems that are connected to the same network but have their own set of rules and permission set at local level. With a Domain you have a group of systems that are bound by the rules of centralized authentication server. In a Domain each system has to connect through the Domain server using provided credentials.

5. What is 255.255.255.255 used for?

A broadcast address is always relative to a given network, there is no broadcast per se; when you have a network, you can compute its broadcast address by replacing all the host bits with 1s; simply put, the broadcast address is the highest numbered address you can have on the network, while the network address is the lowest one (with all host bits set to 0s); this is why you can't use either of them as actual host addresses: they are reserved for this use.

                  If your network is 192.168.1.0/24, then your network address will be 192.168.1.0 and your broadcast address will be 192.168.1.255.

If your network is 192.168.0.0/16, then your network address will be 192.168.0.0 and your broadcast address will be 192.168.255.255.

And so on...

255.255.255.255 is a special broadcast address, which means "this network": it lets you send a broadcast packet to the network you're connected to, without actually caring about its address; in this, is similar to 127.0.0.1, which is a virtual address meaning "local host".

6 Can you name different types of network cables?

Cat-5 runs at 100Mb/s maximum, Cat-5e can run up to 1Gb/s, and Cat-6 can run up to 1OGb/s connection speed. All cables are limited to 100 meters distance in order to run at optimum speed

7 What is TCP/IP?

Transmission Control Protocol/Internet Protocol (TCP/IP) is a networking protocol that allows two computers to Communicate. TCP is used in conjunction with IP in order to maintain a connection between the sender and the target and to ensure packet order.

The Internet Protocol (IP) is the address system of the Internet and has the core function of delivering packets of information from a source device to a target device. IP is the primary way in which network connections are made, and it establishes the basis of the Internet. IP does not handle packet ordering or error checking. Such functionality requires another protocol, typically TCP

8. What is UDP? Use of UDP?

UDP is a communication protocol used across the Internet for especially time-sensitive transmissions such as video playback or DNS lookups. It speeds up communications by not requiring what’s known as a “handshake”, allowing data to be transferred before the receiving party agrees to the communication. This allows the protocol to operate very quickly, and also creates an opening for exploitation.

9. What is Proxy Server? Use of Proxy Server?

A proxy server is basically another computer which serves as a hub through which internet requests are processed. By connecting through one of these servers, your computer sends your requests to the server which then processes your request and returns what you were wanting. In this way it serves as an intermediary between your home machine and the rest of the computers on the internet.

If you want to surf the web anonymously then proxies can provide you with a means to hide your home IP address from the rest of the world. By connecting to the internet through proxies, the home IP address of your machine will not be shown but rather the IP of the proxy server will be shown. This can provide you with more privacy then if you were simply connecting directly to the internet

10. What is the maximum length of UTP cable allowed?

The maximum length of UTP is 90 to 100 meters for a single segment connection. If you have a switch or a repeater it can compensate for this limitation.

11. How can you tell a connection is passed between local host and server?

The tracert command is a Command Prompt command that's used to show several details about the path that a packet takes from the computer or device you're on to whatever destination you specify. It is used for troubleshooting dead connections as well.

12.  What is VPN Network? What is the use of it?

In very simple terms, a VPN connects your PC, smartphone, or tablet to another computer (called a server) somewhere on the internet, and allows you to browse the internet using that computer’s internet connection. So if that server is in a different country, it will appear as if you are coming from that country, and you can potentially access things that you couldn’t normally.

Bypass geographic restrictions on websites or streaming audio and video.

Watch streaming media like Netflix

Protect yourself from snooping on untrustworthy Wi-Fi hotspots.

Gain at least some anonymity online by hiding your true location.

Protect yourself from being logged while torrenting.

13. What is DHCP?

DHCP (Dynamic Host Configuration Protocol) is a network management protocol used to dynamically assign an Internet Protocol (IP) address to any device, or node, on a network so they can communicate using IP. DHCP automates and centrally manages these configurations rather than requiring network administrators to manually assign IP addresses to all network devices. DHCP can be implemented on small local networks, as well as large enterprise networks.

DHCP will assign new IP addresses in each location when devices are moved from place to place, which means network administrators do not have to manually configure each device with a valid IP address or reconfigure the device with a new IP address if it moves to a new location on the network.

14. What is FTP?

FTP stands for File transfer protocol.FTP is a standard internet protocol provided by TCP/IP used for transmitting the files from one host to another.It is mainly used for transferring the web page files from their creator to the computer that acts as a server for other computers on the internet.It is also used for downloading the files to computer from other servers.

15. What is Subnet?

A subnet is a logical partition of an IP network into multiple, smaller network segments