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.
It support MD5 authentication.
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 188.8.131.52
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