Tunnel unstable

[mohd.jaleel]

I am working as Technical support

Here is the situation .

Two location A and B

A side there are 2 tunnels build on Ethernet0/0

in this 2 tunnels one tunnel is flapping frquently but the other tunnel is stable since a week .

logs at A end router

.Dec 6 23:35:59 UTC: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.233 (Tunnel1) is down: peer restarted

.Dec 6 23:36:01 UTC: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.233 (Tunnel1) is up: new adjacency

.Dec 6 23:42:07 UTC: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.233 (Tunnel1) is down: peer restarted

.Dec 6 23:42:08 UTC: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.233 (Tunnel1) is up: new adjacency

.Dec 6 23:45:21 UTC: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.233 (Tunnel1) is down: interface down

At the B end there are many tunnels

At B end tunnel is build on FastEthernet1/0

Error observed

Dec 6 23:42:04 GMT: destroy peer: x.164.84.234

Dec 6 23:42:07 GMT: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.234 (Tunnel110) is up: new adjacency

Dec 6 23:42:08 GMT: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.234 (Tunnel110) is down: K-value mismatch

Dec 6 23:42:08 GMT: destroy peer: x. 164.84.234

Dec 6 23:42:12 GMT: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.234 (Tunnel110) is up: new adjacency

Dec 6 23:45:15 GMT: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 254: Neighbor x.164.84.234 (Tunnel110) is down: interface down

K value error mismatch is observed .Please let me know how to fix the K value mis match problem here, and please let me know if u need any further information .

[thisisshanky]

Is this a DMVPN tunnel ? or just pure IPSEC over GRE ? What IOS version and router platform are involved ?

Have you adjusted any of the metrics (k values) using metric weights command ? Please paste sh run (mask passwords and public IPs)

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800ca762.html

PS: Please remember to rate replies!

[Richard Burts]

The K value mismatch is the result of different versions of IOS on the two routers. There is a fairly new feature in EIGRP where EIGRP will send a "goodby" message if it is about to take down an interface or terminate a neighbor relationship (based on timeout of hello or protocol stopping or some issue). When the router with newer IOS sends the goodby message (which has its K values set to zero) the router with the older IOS does not understand the goodby message concept and interprets the message as a K value mismatch. If you want to fix this error then you should upgrade the IOS version to a version that does understand the goodby message.

This does not address the underlying problem of why the router is tearing down the neighbor relationship. It probably represents a packet loss issue somewhere along the data path between the routers. Ultimately you should investigate this problem. But I believe the original question was about the K value mismatch and I have provided information for that issue.

HTH

Rick