EIGRP Flapping on WAN sub interfaces

[gajanangavli]

Hi All,

we have below connectivity

WAN CE ---> SW (3750) ---> ISP MUX --> ISP Router,  on CE router side we have created sub interface on which EIGRP is running with Service provider.It is flapping daily .ISP confirmed ,as they dont have any issue.We are facing this issue for more than 3 Sites . 

Oct 25 17:27:16.112: %DUAL-5-NBRCHANGE: EIGRP-IPv4 222: Neighbor X.X.X.X (GigabitEthernet0/0/3.500) is down: Interface PEER-TERMINATION received

Oct 25 17:27:17.295: %DUAL-5-NBRCHANGE: EIGRP-IPv4 222: Neighbor X.X.X.X (GigabitEthernet0/0/3.500) is up: new adjacency

CE-ROUTER#sh int Gi0/0/3.500
GigabitEthernet0/0/3.500 is up, line protocol is up
  Hardware is SPA-8X1GE-V2, address is 30f7.0dc9.8c03 (bia 30f7.0dc9.8c03)
   Internet address is X.X.X.X/30
  MTU 1500 bytes, BW 25000 Kbit/sec, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation 802.1Q Virtual LAN, Vlan ID  500.
  ARP type: ARPA, ARP Timeout 04:00:00
  Keepalive not supported
  Last clearing of "show interface" counters never

No physical link flaps observed.

V

[Richard Burts]

The error message very clearly indicates that there is some problem on the neighbor side of the connection. The error message says:"Interface PEER-TERMINATION received". The peer termination says that the neighbor has decided for some reason to tear down the neighbor relationship. I suggest that you talk to them again, and point out this error message.

They may not see any interface go down and that might be the basis for them to say that there is no problem. But the error message does indicate that there is something on their end. It may be something like packet loss. If there is packet loss and you lose 3 consecutive hello messages then EIGRP will treat that as an error and will tear down the neighbor relationship. I wonder if something like that is going on.

HTH

Rick

[Hemakumar Sampath]

Please verify the Bandwidth Utilization also, since the protocol used is EIGRP i would suggest to check even the bandwidth part also.

[smitesh kharecha]

Hi,

In continuation with Rick and Hemakumar's suggestion, I would also suggest to checkout the following points:

1. Cabling at each point in between.

2. Check at your switch whether interface is going down or whether it is accumualting errors.

3. Debugs can give you better insight, why you are receiving peer termination.

Regards,

Smitesh