EIGRP neighbor not found

[gaoyang]

the Eigrp Neighbor is down very often, but the network link is always up

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: New peer 10.2.3.6

16w4d: EIGRP: New peer 10.2.3.7

16w4d: EIGRP: New peer 10.2.3.3

16w4d: EIGRP: New peer 10.2.3.1

16w4d: EIGRP: New peer 10.2.3.9

16w4d: EIGRP: New peer 10.2.3.2

16w4d: EIGRP: New peer 10.2.3.11

16w4d: EIGRP: New peer 10.2.3.5

16w4d: EIGRP: New peer 10.2.3.8

16w4d: EIGRP: New peer 10.2.3.4

16w4d: EIGRP: New peer 10.2.3.10

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.1 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.4 went down on FastEthernet1/0

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.6 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.9 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.5 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.8 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.3 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.7 went down on FastEthernet1/0

16w4d: EIGRP: Holdtime expired

16w4d: EIGRP: Neighbor 10.2.3.11 went down on FastEthernet1/0

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

16w4d: EIGRP: Neighbor not yet found

kfq-01#ping 10.2.3.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.2.3.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

kfq-01#

[hbaerten]

Are the timers configured the same on all routers?

[ruwhite]

The message "Neighbor not yet found," specifically means this router is receiving updates, queries, or replies from an EIGRP router on this link it does not recognize as a neighbor.

So, for instance, if the hold timers are mismatched on two routers:

A---B

Suppose that A has a hold time of 10 seconds, and B has a hold time of 30 seconds. If communication between the two routers stops for 15 seconds, then B is going to reset its adjacency with A during the outage, but A is not going to reset its adjacency with B. When the outage is over, it's possible for A to send a few packets to B before B gets an hello from A, marks it as a new neighbor, and sends the first update with the init bit set (which will reset the adjacency on A). Note this shouldn't be all that long, and you're seeing a lot of packets, which leads me to believe this isn't the case.

BTW, the hello and hold timers don't have to match on all the EIGRP routers on the same link. Every hello that A sends has it's hold time in the hello paclet. Each hello B receives from A, it resets A's hold time locally to the hold time in the hello packet, and then starts counting the second down, resetting as needed. So, in EIGRP, matching hold times are not a requirement. So, mismatched hold times cannot be the root of the problem here.

The real problem is that you are seeing the hold time of all the neighbors fail, it looks like on a periodic basis. Depending on what the timing is here, it could be a set of constantly flapping neighbors.

What are the SRTT and RTO from show ip eigrp neighbor on these routers? If the SRTT never makes it above 0, and the RTO never changes from 5000, then you have neighbors that are most likely constantly flapping, and aren't ever fully building an adjacency.

The first thing I'd do is to ping 224.0.0.10, to make certain you are getting multicast through from each router on the network. After this, I'd start checking input and output queues, to make certain you aren't dropping the packets necessary to keep the adjacencies up between all of these routers. I would assume the problem is on this router only, that the other routers are keeping there adjacencies with each other just fine?

Russ.W

[deilert]

Can you paste in sh int f1/0 and a sh int or a sh port for the directly connected switch port .