Hi,
Here are few questions?

1. What is FTP & UDP?
2. What is the difference between switch & router?
3. As i know that DHCP works under a protocol in the name of "DORA". Can
anyone explain me about "DORA"?
4. Please explain me about the concept of "Kerboros" protocol & when i
works?

DHCP clients use DORA(Discover,offer,request,and Acknowledgements) to obtain a DHCP ip address lease,to see the acitve DHCP leases, use the DHCP administrative tool,

FTP is a file transfer protocol that works on port 21. Most famous FTP software is Cuteftp

UDP stands for User Data gram protocol is one of the two main protocols used in IP Networks, Unreliable protocol , Yu cant detect any error , It works on Transport layer.

give me some tips about networking

Normally, networking is means connect the difference network into a big one. difference network is refer to the LAN in difference part of the branch of a big company, etc.

switch and router is two difference type device, switch is used for layer 2 switch mainly, but right now, switch can work as a router in layer 3 mode, but the mainly difference is performance. switch's layer 2 works better than router.

router work's in layer 3, and only have limited layer 2 funtions, it's used for routing, and have much high performance in routing than switch.

FTP-File transfer protocol is a network protocol used to transfer data from one computer to another through a network, such as over the Internet.
UDP-User Datagram Protocol .Using UDP, programs on networked computers can send short messages sometimes known as datagrams

DORA is the process that DHCP goes through to assign IP addresses to computers, printers, etc throughout a network. The letters in DORA stand for DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, and DHCPACK. Kerberos is more in depth to explain, basically to say it in a few words, it's used for authentication for IPSec using secret-key cryptography.

Also, with FTP and UDP, FTP is better for downloading stuff like pictures and music, because it traces each packet that is sent and makes sure nothing is missing. UDP, on the other hand, isn't very reliable because it doesn't trace packets, so it's ok to use when you're streaming videos because it's not like you're going to miss a millisecond clip in a video...

WHAT is the difference between EIGRP and O.P.S.F.??

1-- ftp is file transfer protocol. ftp is a application that works in application
layer of osi model.

one good reason to use ftp is to download files. ftp is much fater than
standard http downloads

2--UDP is nothing but user datagram protocol this protocol works at
transport layer of osi model.
udp is un reliable ,connectionless datagram protocol " unreliable" merely
means that the protocol has no technique for verifying that the data
reached the other end of network correctly
3--swithes are network device .
to improve network performance switches were developed.it keeps the
table mac address per port to make switching decision

4--router is network device to send packets between different network routers are used

what is main diffrence between DR and BDR

FTP Works with Appication Layer port no 21

UDP Means User Data gram Potocol Port no 17 this is connection less Oriented Protocls , example : Odinary Post it swork with tranport Layer

EIGRP this is Hybrid protocols ( Distance Vector protocol and Link State protocol )
1 ) Administrative Distance Internal 90 and External 170
2 )it can be Support VLSM
3 ) Meric ( Bandwith + Dealy + Reliablity+ MTU
4)

hi,
i've cts interview..
pls goe me some commonly asked basic interview questions..

Kerberos uses as its basis the Needham-Schroeder protocol. It makes use of a trusted third party, termed a key distribution center (KDC), which consists of two logically separate parts: an Authentication Server (AS) and a Ticket Granting Server (TGS). Kerberos works on the basis of "tickets" which serve to prove the identity of users.

The KDC maintains a database of secret keys; each entity on the network — whether a client or a server — shares a secret key known only to itself and to the KDC. Knowledge of this key serves to prove an entity's identity. For communication between two entities, the KDC generates a session key which they can use to secure their interactions

FTP - File Transfer Protocol.
Used to transfer files from one point to the other.
Port no - 20-Control,21-Data.
Works on layer 3,4,6,7

Switch is a layer 2 device , works with mac address , faster than router , broadcasts the packets with in the network.when a switch is connected to a lan say 20 pcs first of all, it broadcasts the packets to all the 20 systems , learns the mac address of the pcs from their response builds up the mac address table.

So when a packet has to sent again to a particular pc say pc1,it wont broadcast to all the systems just it ll unicast ie, send the packet directly to the pc1.More over we can effectively maintain the VLANs , sorting them etc

Router is a layer 3 device capable of broadcasting packets out of a particular network.using a router we can wave a path for packets for a network, get it filtered using access list etc....