Importan WAN Interview Questions

Q – 1 What is a VLAN and what does VLAN provide?

Ans- A technology called VLAN (Virtual LAN broadcast domains logically segmented on an Ethernet switch) trunking that was once primarily the domain of network switches has now trickled down to the rest of the Data Center to address these issues. Now it is possible for these multi-homing devices to be multi-homing in function without the need for multiple physical network adapters and the additional infrastructure associated with them.

VLAN trunking allows a single network adapter to behave as ?n? number of virtual network adapters, where ?n? has a theoretical upper limit of 4096 but is typically limited to 1000 VLAN network segments. In the case where a single gigabit Ethernet adapter is trunked in place of using multiple FastEthernet adapters, higher performance at a lower cost while increasing flexibility can be achieved. This really is the best of all worlds. In this article, I will give you an overview of VLAN trunking, how it works what it is used for.

VLAN is a technology by which we can administratively assign different ports of the same layer2 switch to different subnetworks. This is particularly useful when different departments of a company have offices in different floors of the same office. The different departments can be connected via a layer2 switch , which is having configuration for other subnetwork also. So practically the same switch acts as if it is more than one.

Packets destined for the specific subnetwork are forwarded to those ports only. But the switch does not make any routing decisions. For interconnecting different subnetworks, routers are needed.
VLAN essentially provides segmentation between different subnetworks.

Q – 2 Explain Why should we care about the OSI Reference Model ?
What is the main purpose for creating this OSI model?
Why it is a layered model?

Ans- OSI refrence model proposed by ISO.
we care about OSI because
1. It filters all the network communication into the small and simple component.
2. It allows vendor development through the standard network components as well as various types of network hardware and software to communicate.
3 and the changes in one layer affecting to the another layer, so it does not hamper development.

Main purpose to create this model that it provides a framework to implement and developed the network components and internetworking scheme as well as all the vendors developed there produt under a single standard.

Q – 3 What is wide area networks?

Ans- Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries

WAN-Wide Area Network…..many MANS are joined to form a WAN.It carry voice,data &speech efficiently through very long distances…may be through out the country.The most Common & readily understandable example is INTERNET

Q – 4 What is MAC address?

Ans- The address for a device as it is identified at the Media Access Control (MAC) layer in the network architecture. MAC address is usually stored in ROM on the network adapter card and is unique.

MAC (Media Access Control) address is a unique address of a device and stored in ROM on the network adapter card. it is 48 bit long.

Q – 5 Explain If you are given the IP address can u tell how many computers can be connected?What do you look at?

Ans- Normally in IP address in fourth tab usually they will give the serial number of the using computer. in that case we can say how many computers are there. if not its impossiable to say.

This all depends on the type of IP address.That is the class it belongs to.All that is needed to be done is to subnet the given IP adress.

This is very simple open my network place and select work group in work group count no. of systems by name of computers.

Q – 6 Explain What is wide-mouth frog?

Ans- Wide-mouth frog is the simplest known key distribution center (KDC) authentication protocol.

When hierarchical routing is used, the routers are divided into what we call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.

Q – 7 What is region?

Ans- When hierarchical routing is used, the routers are divided into what we call regions, with each router knowing all the details about how to route packets to destinations within its own region, but knowing nothing about the internal structure of other regions.

Q – 8 Explain What is SIP? how does it work? what are the alternatives if any? current and future practice and application standards?

Ans- SIP is meant for Session Initiation Protocol. It works in application layer. It specially used for initiating, modifying and terminating a session. you can find all details in rfc3261.

Q – 9 Explain the difference between switch and Hub?

Ans- HUb:

limited port compare to switch.less speed compare to switch because more collision.

Switch:

To Avoid collision we use switch. In switch Each Port having own collision Domain.

HUB:

Hub is a layer-1 device,in this data transmission in the form of bits.

SWITCH:

Switch is a layer-2 device,in this data transmission in the form of frames.

Switches
Bi directional information.
It exchanges the data

Hubs
to connect the computers
It gives the acknowledgment for received data

Q – 10 Explain What are the types of Transmission media?

Ans- Signals are usually transmitted over some transmission media that are broadly classified in to two categories:-

Guided Media:

These are those that provide a conduit from one device to another that include twisted-pair, coaxial cable and fiber-optic cable. A signal traveling along any of these media is directed and is contained by the physical limits of the medium. Twisted-pair and coaxial cable use metallic that accept and transport signals in the form of electrical current. Optical fiber is a glass or plastic cable that accepts and transports signals in the form of light.

Unguided Media:

This is the wireless media that transport electromagnetic waves without using a physical conductor. Signals are broadcast either through air. This is done through radio communication, satellite communication and cellular telephony.

Q – 11 What is Difference between the communication and transmission?

Ans- Transmission is a physical movement of information and concern issues like bit polarity, synchronisation, clock etc.

Communication means the meaning full exchange of information between two communication media.

Transmission is a one way scheme while communication is two-way scheme communication bi-directional transmission unidirectional