Routing Description

Routing

Forwarding of packets into different networks is called routing. As I have told you in the previous posts that assigning an IP in a router of a network will be the default gateway for all the devices connec ted in that network. It is necessary for a router to have different interface in its network. 

Routing Table 

A routing table is a data table in a router that shows all the routes to particular different networks.

The command to show routing table and the result for this command is shown below

Command

# show ip route

Result

C E0     10.0.0.0/8

C E1     20.0.0.0/8 

where C is for "Directly Connected"

How can a Node recognized that a packet which is being routed is a remote or a local. The answer is simple we take the source and destination IP address and perform the AND operation with the subnet we will get the default gateway. If the default gateway is the same for both than the packet is local or otherwise remote.

                              Source                                destination

    IP Address      10.0.0.1                                  10.0.0.2

    Subnet             255.0.0.0                               255.0.0.0

                           

Performing AND operation and we get

                              Source                                 destination

                            10.0.0.0                                    10.0.0.0

Same Default gateway means the packet is local not remote.

Those Id's which we are not connected with we must tell them manually through static routing. For Branch communication, Routing is very important.