# 1. Which class of addressing is used for small LAN and why?

Class C IP address is used for small LAN among class A, Class B and Class C.

Explanation: Among Class A, B and C Class B has Two bytes and class A has three bytes reserved for host address, while Class C use One byte for host address. So class C is ideal for small LAN as range of class C is 192-223 with 254 numbers of hosts.

#2. What are the techniques involved in transmitting the data from the server via router?

The first step involved in transmitting the data from the server is to check the router IP address. If the router IP address is correct then the next step is done by the router itself. The router recognizes the destination from the routing table and sends the packet of data. After this is done, similar process is executed by the next network.

#3. How does ARP works?

In networking, ARP (Address Resolution Protocol) associates the IP address to a network node of the physical hardware address. The ARP creates ARP CACHE/TABLE that maps the hardware address of the nodes with the IP address on the local network. Based on the IP address the ARP check’s whether the hardware address exists in its ARP TABLE. It matches found then the transmission to that IP address is done quickly as destination is known.

#4. What is Kerberos protocol?

Kerberos protocol is a network authentication protocol. To provide strong authentication for server – client applications it utilizes symmetric cryptography (secret key). Kerberos is specially designed for addressing the problem of authentication over internet and also uses dedicated authentication servers. The authentication server contains all secret keys for every user and servers in the network and avoids misuse of any information.

#5. Define RIP and discuss its use?

RIP whose full form is routing information protocol. RIP is a dynamic routing protocol which is used in local and wide area network. RIP uses distance vector routing algorithm and is classified as an interior gateway protocol.

Rip is used where there is less number of routers as the maximum hop count of RIP is 15. So it works on internal networks which have lesser network connected to the internet and helps router to adapt changes dynamically by gathering information about the networks each router can reach and the distance between those networks.

#6. What is TCP/IP?

TCP/IP is the set of communication protocols which is used for internet and other similar kind of networks. TCP/IP is the internet protocol suite in which TCP stands for Transmission control protocol and IP stands for Internet protocol. These were the first two networking protocols introduce in this category.

#7. Why cross cable is used to connect same devices?

In case of similar devices NIC (Network Interface card) of device 1, 2 are used for transmission and 3, 6 for receiving of data. While in case of hub/switch/dissimilar devices it uses NIC (Switch/Hub) 1, 2 for receiving and 3, 6 for transmission of data. That’s why straight cable is used for dissimilar host and cross cable for similar hosts. If cross cable is not used for similar devices then data can not be transferred.

#8. Discuss OSPF Protocol?

OSPF stands for Open Shortest Path First. OSPF is a link-state routing protocol which is used for sending link -state advertisements (LSAs) to all other routers within the network. Since OSPF routers collects link-state information that is why they use SPF (Shortest path First) algorithm to calculate the shortest path to each node. OSPF has two primary characteristics. Firstly, the protocol is open and secondly it is based on SPF algorithm.

#9. How SSO helps in authentication technologies?

SSO which generally stands for Single Sign – On, provides access control to a user. With the SSO property a user gets logs in information once and gain access to all the system without entering log in details again and again. With the help of this Single Sign – On Information a user is authenticated and is allowed to access system unless and until the users signs – off.

#10. What are Sockets?

A socket is simply an end point of bidirectional communication. Internet sockets are API available in an operating system which is used for inter – process communications. Three major operations that can be performed on a socket are:-

Control Operation: This operation include creating and accepting a connection on a socket, associating a socket with port number and lastly destroying a socket.

Data Transfer Operations: Writes data to application through sockets and even reading data from applications through it.

Status Operations: This operation helps to find the IP address associated with a socket.

#11. Can IP protect data in a network?

The data protection part is handled by the transport protocol. TCP and UDF have mechanisms which ensure that the data which is being delivered to an application is error free. However, IP try to protect the IP packet’s header which is the small part of each packet which controls the flow of packet through the network. This is done by calculating and associating a checksum in the IP packet’s header field before transmitting over the network and the receiver checks the IP packet’s header before procession the whole packet. A packet whose header does not match is discarded.

#12. What is UDP?

UDP generally stands for User datagram Protocol. An unreliable data transfer service is provided by UDP between two end points. UDP transfers packets over network being dependent on the IP. UDP assures integrity by adding a checksum to the data before transmission of the data over network but it never guarantees delivery of data to the destination and in the same order.

#13. How many layers are there in a network?

The seven layers in a network which works together to transfer/receive packets are:-

1. Application layer.

2. Presentation layer.

3. Session layer.

4. Transport layer.

5. Network layer.

6. Data link layer.

7. Physical layer.