Debug EIGRP Packet - Received HELLO on Loopback1 nbr

[mahesh18]

                   Hi Everyone,

Two Switches  are working fine as eigrp neis and authentication is enabled on them.

Sw1 has loopback interface

Loopback1              3.3.3.3         YES manual up                    up

router eigrp 42

no auto-summary

network 3.3.3.3 0.0.0.0

network 172.16.12.1 0.0.0.0

!

sh ip eigrp nei

EIGRP-IPv4:(42) neighbors for process 42

H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq

                                            (sec)         (ms)       Cnt Num

0   172.16.12.2             Fa0/31            11 00:36:36   16   200  0  12

Here is debug eigrp packet  output

EIGRP: Received HELLO on Loopback1 nbr 3.3.3.3

EIGRP: Received HELLO on FastEthernet0/31 nbr 172.16.12.2

Need to understand when it receives HELLO on loopback  interface why  it show itself as nei?

Is this due to loopback is seen as logical interface  or is this default network behaviour?

When it receive HELLO on physical  interface it correctly shows nei as  other switch.

Regards

Mahesh

Message was edited by: mahesh parmar

Message was edited by: mahesh parmar

[John Blakley · Accepted solution]

Mahesh,

It's going to receive the multicast 224.0.0.10 since you have it listening on that interface. You can do a "passive-interface Lo1" and it won't send/receive on it any longer..

HTH,
John

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[Rasika Nayanajith · Accepted solution]

Agree with John, below link should give some more details what passive-interface x do on EIGRP

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f0a.shtml

Rasika

[mahesh18]

Many  thanks John and Rasika

Regards

Mahesh