To configure EIGRP, we have to use the command "router eigrp " on the global configuration mode of the router.
The routers which we want to form the neighborships should be configured with the same "ASN" number.
The second statement is to add the "network " command. The router checks the network id mentioned in the network command and enables eigrp on the interfaces matched by the network command.
we have the option to add the wildcard mask to the network id in the network command. If we don't mention wildcard mask, then the eigrp assumes the network id mentioned as the classful network.If the wildcard mask is mentioned then it considers it as the subnet and enables eigrp only on the subnet which are indicated by the network id and the wildcard mask combination.
When eigrp is enabled on the required interfaces, the router starts sending hello messages on the eigrp enabled interfaces. These hello messages are sent on the multicast address. Router also advertises the connected subnets to the eigrp neighbors.
When eigrp is enabled on the required interfaces, the router starts sending hello messages on the eigrp enabled interfaces. These hello messages are sent on the multicast address. Router also advertises the connected subnets to the eigrp neighbors.
EIGRP works with three tables.
1)EIGRP neighbor table.
2)EIGRP topology table
3)IP Routing table.
EIGRP neighbor table consists of neighboring routers.
EIGRP topology table contains information about all the routes learned from eigrp neighbors.
The best routes chosen from the EIGRP topology table are placed in the routing table.
2)Partial update message.
When eigrp is enabled on the required interfaces, the router starts sending hello messages on the eigrp enabled interfaces. These hello messages are sent on the multicast address. Router also advertises the connected subnets to the eigrp neighbors.
EIGRP works with three tables.
1)EIGRP neighbor table.
2)EIGRP topology table
3)IP Routing table.
EIGRP neighbor table consists of neighboring routers.
EIGRP topology table contains information about all the routes learned from eigrp neighbors.
The best routes chosen from the EIGRP topology table are placed in the routing table.
Update messages
In EIGRP, topology information is exchanged using the update messages. Update messages destination address is the multicast address 224.0.0.10. The update messages uses Reliable Transport Protocol(RTP).Types of update messages
1)Full update message2)Partial update message.