EIGRP Adjacency flapping, IPv6

[techchi]

Feb 13 11:52:38.554: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::2 (Ethernet0/0) is down: holding time expired

*Feb 13 11:52:46.255: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::1 (Ethernet0/0) is up: new adjacency

*Feb 13 11:52:50.946: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::2 (Ethernet0/0) is up: new adjacency

*Feb 13 11:53:01.260: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::1 (Ethernet0/0) is down: holding time expired

*Feb 13 11:53:01.262: EIGRP: Build goodbye tlv for FE80::1

*Feb 13 11:53:05.955: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::2 (Ethernet0/0) is down: holding time expired

*Feb 13 11:53:27.259: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::1 (Ethernet0/0) is up: new adjacency

*Feb 13 11:53:32.060: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::2 (Ethernet0/0) is up: new adjacency

*Feb 13 11:53:42.267: %DUAL-5-NBRCHANGE: EIGRP-IPv6 100: Neighbor FE80::1 (Ethernet0/0) is down: holding time expired

*Feb 13 11:53:42.276: EIGRP: Build goodbye tlv for FE80::1

[techchi]

R2{Eth0/0}-----{Eth2/0}SW1-vlan23{Eth2/1}------{Eth0/0}R3

[techchi]

In wireshark all I see "Parameters: Peer Termination" is this Frame 116: 104 bytes on wire (832 bits), 104 bytes captured (832 bits) on interface 0

Ethernet II, Src: aa:bb:cc:00:70:00 (aa:bb:cc:00:70:00), Dst: IPv6mcast_0a (33:33:00:00:00:0a)

Internet Protocol Version 6, Src: fe80::3, Dst: ff02::a

0110 .... = Version: 6

.... 1110 0000 .... .... .... .... .... = Traffic class: 0xe0 (DSCP: CS7, ECN: Not-ECT)

.... .... .... 0000 0000 0000 0000 0000 = Flow label: 0x00000

Payload length: 50

Next header: EIGRP (88)

Hop limit: 1

Source: fe80::3

Destination: ff02::a

[Source GeoIP: Unknown]

[Destination GeoIP: Unknown]

Cisco EIGRP

Version: 2

Opcode: Hello (5)

Checksum: 0xec6d [correct]

Flags: 0x00000000

.... .... .... .... .... .... .... ...0 = Init: Not set

.... .... .... .... .... .... .... ..0. = Conditional Receive: Not set

.... .... .... .... .... .... .... .0.. = Restart: Not set

.... .... .... .... .... .... .... 0... = End Of Table: Not set

Sequence: 0

Acknowledge: 0

Virtual Router ID: 0 (Address-Family)

Autonomous System: 100

Parameters: Peer Termination

Type: Parameters (0x0001)

Length: 12

K1: 255

K2: 255

K3: 255

K4: 255

K5: 255

K6: 255

Hold Time: 15

[Expert Info (Note/Response): Peer Termination]

[Peer Termination]

[Severity level: Note]

[Group: Response]

Software Version: EIGRP=14.0, TLV=2.0

Type: Software Version (0x0004)

Length: 8

EIGRP Release: 14.00

EIGRP TLV version: 2.00

Peer Topology ID List

Type: TopologyID List (0x00f5)

Length: 10

TID List Flags: 0x0000

TID List Size: 2

1 TIDs

[techchi]

Here is the EIGRP Packet debug on R3

[grabonlee]

Your attachment R2 Neighbors shows a different interface for the adjacency (E0/1) from the flapping interface (E0/0) and the your topology drawing.

1. R2 Neighbors shows int E0/1 with link-local FE80::1 and not E0/0

2. Can you confirm that all the interfaces on the 2 switches are on Vlan 23, as your diagram only shows vlan 23 for one switch

Can you post the Eigrp neighbor for R3?

[Richard Burts]

It is not clear to me which device generated the log messages in the original post. But a couple of things are clear.

- this device sees 2 neighbors on its Ethernet interface.

- each this device receives a message from a neighbor and attempts to establish a neighbor relationship.

- 15 seconds later the device marks the neighbor as down because of hold time.

- after a short amount of time the cycle repeats.

Can we see from at least one of those neighbors what they think is going on? 

HTH

Rick