ROUTING IN CISCO.

Router


It is a device used to communication between two

different networks.
􀂇 Routing

It is process of sending the data packets through the

best path to reach the destination.


􀂇 Default Gateway

It gives the exit point (or) entry point to reach the destination.
 
Use of Routing and Remote Access Service in


Windows Server 2003

􀂇 Routing and Remote Access is a service that

performs routing as one of its multiple processes.
 
What is Network Address Translation ?


􀂇 Provides access to the Internet from a

protected private address range

􀂇 Translates Private IP􀂶s to Public IP􀂶s & vice-versa for

outgoing and incoming traffic

􀂇 Hides private IP address range from the Internet

􀂇 Can be used with DHCP or can be configured to assign IP to Client
 
5


IP = 10.0.0.3

IP = 10.0.0.4

IP = 10.0.0.5

1. The client sends the packet to the computer running NAT

4. The computer running NAT determines the destination,

changes the packett header, and sends the packett tto the client

2. The computer running NAT changes the packet header and

sends the packet over the Internett tto the Web server

3. The Web server sends a reply to the computer running NAT

Web Server

IP = 66.11.10.12

Computer Running NAT

Internal IP = 10.0.0.1

External IP = 202.153.32.1

Clientt Computers Internet
 
What Is a DHCP Relay Agent?


􀂇 A DHCP Relay agent is a computer or router

that listens for DHCP Broadcasts from DHCP

clients and then relays those messages to DHCP Servers.
 
1-Client 1 broadcasts a DHCPDISCOVER ppaacckkeett


2-Dhcp Reelay agent forwards the DHCPDISCOVER message to the DHCP server

33 Server sends a DHCPOFFER message to the DHCP rellay agent

44 Rellay agent broadcasts the DHCPOFER Packet

55 Cllient1 broadcasts a DHCPREQUEST packet

66 Rellay agent forwards the DHCPREQUEST message to the DHCP serer
77 Server sends a DHCPACK message to the DHCP rellay agent

88 Rellay agent roadcasts the DHCPACK packet