EIGRP - Part 2

EIGRP Topology Information Exchange:

 

 

è    EIGRP Features:

1.       Hello Interval

One router send hello message from its interface to another routers interface.

2.       Hold timer

Timer used to determine when neighbor router id failed , based on router not receiving any EIGRP messages.

3.       Full of partial update

Full update are used when new neighbors are discovered: otherwise partial update used.

4.       Authentication

It support MD5 authentication.

5.       Multiprotocol

Support the advertisement of IPX and AppleTalk routes.

è       Manipulating EIGRP Hello and Hold Timer

Hello message : every 5 second

Hold Timer: 15 second ( 3 Time of Hello message)

Means , every EIGRP router send every 5 second hello message to its neighbor router for updating , Incase neighbor router is failed otherwise lost network connectivity, then it send 3 time hello message its , time duration neighbor router cann’t send and Ack message then EIGRP router declare to failed.

   Manually configure Timer:

         Interface FastEthernet 0/0

         IP hello-interval eigrp 9 2

         IP hold-time eigrp 9 6

 Verify hello timer:  show ip eigrp interface details serial 0/0 (any)

  Verify hold timer:  show ip eigrp neighbors

è       Passive interface :

        When we are enable EIGRP routing on the interface, than that router does two thing:

1.       It find neighbor by sending hello packet via 224.0.0.10

2.       Subnet connected with interface.

If any interface is passive state means it don’t send any hello message.

All interface which is participate in EIGRP routing are state is passive.

We can set manually passive state of router interface:

Router eigrp 1

Passive-interface fastethernet 0/0

And if set active state than use:

No passive-interface fastethernet 0/0

Verify Passive-interface: show ip protocols

 

Enhanced Interior Gateway Routing Protocol (EIGRP)

EIGRP (Enhanced Interior Gateway Routing Protocol)

è      It is a hybrid protocol, which elect the neighbor based of hope count, cost and it also considered best bandwidth.

è      It have administrative distance 90(internal), external 170.

      It use multicast address 224.0.0.10 for send error packet, any troubleshooting issue and full/partial update.

è      It also use DUAL (Diffusing update algorithm) algorithm.

è       It support both FLSM and VLSM routing.

è    It Support maximum 255 hope count. ( by default 100)

è      It use RTP (Reliable transport protocol) for sent update message.

è     It use ASN (autonomous system No.) number for neighbor discovery, if neighbor router have  different  autonomous system no. than it not update in our routing table. We can assign autonomous system no. from 1 to 65535.

 

è     EIGRP enabled command :  ->

1.       Router eigrp <ASN>

2.       Network net-id wc-mask 

è   EIGRP verification command:

1.       Show ip eigrp interface

    List of all eigrp interface on which is eigrp is enabled  ( it find based on network command).

2.       Show ip protocol

List of all routing protocol which is enabled on router and list of neighbor ip address.

3.       Show ip eigrp neighbor

List of all known neighbor which have same as no. . not mismatched.

4.       Show ip eigrp topology

List of all successor and feasible successor path. Donn’t whole topology.

5.       Show ip route

List of all ip routing table with the code of D