Network Engineer Interview Questions & Answers

Question 1. What Are The Types Of Lan Cables Used? What Is A Cross Cable?

Answer :

Types of LAN cables that are in use are "Cat 5" and "Cat 6". "Cat 5" can support 100 Mbps of speed and "CAT 6" can support 1Gbps of speed.

Cross cable: Its used to connect same type of devices without using a switch/hub so that they can communicate.

Question 2. What Is The Difference Between A Normal Lan Cable And Cross Cable? What Could Be The Maximum Length Of The Lan Cable?

Answer :

The way the paired wires are connected to the connector (RJ45) is different in cross cable and normal LAN cable.

The theoritical length is 100 meters but after 80 meters you may see drop in speed due to loss of signal.

Question 3. What Id Dhcp? Why It Is Used? What Are Scopes And Super Scopes?

Answer :

DHCP: Dynamic host configuration protocol. Its used to allocate IP addresses to large number of PCs in a network environment. This makes the IP management very easy.

Scope: Scope contains IP address like subnet mask, gateway IP, DNS server IP and exclusion range which a client can use to communicate with the other PCs in the network.

Superscope: When we combine two or more scopes together its called super scope.

Question 4. What Is Active Directory?

Answer :

A central component of the Windows platform, Active Directory directory service provides the means to manage the identities and relationships that make up network environments. For example we can create, manage and administor users, computers and printers in the network from active directory.

Question 5. What Is Dns? Why It Is Used? What Is "forward Lookup" And "reverse Lookup" In Dns? What Are A Records And Mx Records?

Answer :

DNS is domain naming service and is used for resolving names to IP address and IP addresses to names. The computer understands only numbers while we can easily remember names. So to make it easier for us what we do is we assign names to computers and websites. When we use these names (Like yahoo.com) the computer uses DNS to convert to IP address (number) and it executes our request.

Forward lookup: Converting names to IP address is called forward lookup.

Reverse lookup: Resolving IP address to names is called reverse lookup.

'A' record: Its called host record and it has the mapping of a name to IP address. This is the record in DNS with the help of which DNS can find out the IP address of a name.

'MX' Record: its called mail exchanger record. Its the record needed to locate the mail servers in the network. This record is also found in DNS.

Question 6. What Is Ipconfig Command? Why It Is Used?

Answer :

IPCONFIG command is used to display the IP information assigned to a computer. Fromthe output we can find out the IP address, DNS IP address, gateway IP address assigned to that computer.

Question 7. What Is Apipa Ip Address? Or What Ip Address Is Assigned To The Computer When The Dhcp Server Is Not Available?

Answer :

When DHCP server is not available the Windows client computer assignes an automatic IP address to itself so that it can communicate with the network cmputers. This ip address is called APIPA. ITs in the range of 169.254.X.X.

APIPA stands for Automatic private IP addressing. Its in the range of 169.254.X.X.

Question 8. What Is A Domain? What Is The Difference Between A Domain And A Workgroup?

Answer :

Domain is created when we install Active Directory. It's a security boundary which is used to manage computers inside the boundary. Domain can be used to centrally administor computers and we can govern them using common policies called group policies.

We can't do the same with workgroup.

Question 9. What Is A Pst File And What Is The Difference Between A Pst File And Ost File? What File Is Used By Outlook Express?

Answer :

PST file is used to store the mails locally when using outlook 2000 or 2003. OST file is used when we use outlook in cached exchanged mode. Outlook express useds odb file.

Question 10. What Is Bsod? What Do You Do When You Get Blue Screen In A Computer? How Do You Troubleshoot It?

Answer :

BSOD stands for blue screen of Death. when there is a hardware or OS fault due to which the windows OS can run it give a blue screen with a code. Best way to resolve it is to boot the computer is "LAst known good configuration". If this doesn't work than boot the computer in safe mode. If it boots up than the problemis with one of the devices or drivers.

Question 11. What Is Ris? What Is Imaging/ghosting?

Answer :

RIS stands for remote installation services. You save the installed image on a windows server and then we use RIS to install the configured on in the new hardware. We can use it to deploy both server and client OS. Imaging or ghosting also does the same job of capturing an installed image and then install it on a new hardware when there is a need. We go for RIS or iamging/ghosting because installing OS everytime using a CD can be a very time consuming task. So to save that time we can go for RIS/Ghosting/imaging.

Question 12. What Is Vpn And How To Configure It?

Answer :

VPN stands for Virtual private network. VPN is used to connect to the corporate network to access the resources like mail and files in the LAN. VPN can be configured using the stepsmentioned in the KB:

Question 13. Your System Is Infected With Virus? How To Recover The Data?

Answer :

Install another system. Insall the OS with the lates pathces, Antivirus with latest updates. Connect the infected HDD as secondary drive in the system. Once done scan and clean the secondary HDD. Once done copy the files to the new system.

Question 14. What Is The Difference Between A Switch And A Hub?

Answer :

Switch sends the traffic to the port to which its meant for. Hub sends the traffic to all the ports.

Question 15. What Is A Router? Why We Use It?

Answer :

Router is a switch which uses routing protocols to process and send the traffic. It also receives the traffic and sends it across but it uses the routing protocols to do so.

Question 16. What Are Manageable And Non Manageable Switches?

Answer :

Switches which can be administered are calledmanageable switches. For example we can create VLAN for on such switch. On no manageable swiches we can't do so.

Question 17. What Is Nic?

Answer :

A network card, network adapter or NIC (network interface controller) is a piece of computer hardware designed to allow computers to communicate over a computer network

Question 18. What Is Usb?

Answer :

Universal Serial Bus (USB) is a serial bus standard to interface devices. Devices like Modem, Mouse, Keyboard etc can be connected.

Question 19. What Is A ‘link’?

Answer :

A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other.

Question 20. What Are The Types Of Lan Cables Used?

Answer :

There are two types of LAN cables used – ‘Cat 5’ and ‘Cat 6.’ Cat 5 can support 100Mbps of speed while Cat 6 can support 1Gbps of speed.

Question 21. What Are ‘firewalls’?

Answer :

Firewalls serve to protect an internal network from external attacks.

Question 22. What Is Rip?

Answer :

RIP (Routing Information Protocol) is used by routers to send data from one network to another.

Question 23. How Many Layers Are There Under Tcp/ip?

Answer :

There are four layers: the Network Layer, Internet Layer, Transport Layer and Application Layer.

Question 24. What Is Ras?

Answer :

RAS (Remote Access Services) refers to any combination of hardware and software to enable remote access to tools or information that typically reside on a network of IT devices.

Question 25. What Is The Difference Between ‘standard’ And ‘extended’ Acl (access Control List)?

Answer :

Standard ACLs are source-based, whereas extended ACLs are source- and destination-based.

Question 26. Define ‘anonymous Ftp’?

Answer :

Anonymous FTP is a way of granting a user access to files in public servers.

Question 27. What Is A Router? What Are Its Basic Roles?

Answer :

A router is a layer 3 network device used to establish communication between different networks.

The roles of a router are –

• inter-network communication
• Best path selection
• Packet forwarding
• Packet filtering

Question 28. What Is A ‘backbone Network’?

Answer :

A backbone network is a centralised infrastructure that is designed to distribute different routes and data to various networks. It also handles management of bandwidth and various channels.

Question 29. Differentiate Between ‘forward Lookup’ And ‘reverse Lookup’ In Dns?

Answer :

Converting names to IP addresses is called forward lookup.

Resolving IP addresses to names is called reverse lookup.

Question 30. A Gateway Works In Which Layer Of The Osi Model?

Answer :

Transport layer.

Question 31. How Many Layers Are There In The Osi Reference Model? What Are They?

Answer :

There are 7 layers: physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer.