BGP maxas-limit bug

[paul amaral]

when setting the maxas-limit I seem to be running into a bug?, not sure, %BGP-6-MSGDUMP_LIMIT: unsupported or mal-formatted message received. Has anyone else obverse this on ASR1001-x IOS 16(everest) ? It looks cosmetic but I cant seem to stop it. I tried neighbor x.x.x.x dont-capability-negotiate but that didnt seem to work. The error is triggered when you receive a prefix with AS path longer the maxas-limit configured.

TIA

paul 

[Giuseppe Larosa]

Hello Paul,

other people have reported a lot of log messages after enabling the feature

see the following thread

https://community.cisco.com/t5/routing/bgp-maxas-limit-how-many-and-limit-logging-of-drops/td-p/1909048

So it might not be a bug, even cosmetic but a wanted behaviour.

Hope to help

Giuseppe

[paul amaral]

I agree its probably a bug, I should see be able to see that a prefix was rejected like on other platforms but not the complaint

May 24 11:51:04: %BGP-6-MSGDUMP_LIMIT: unsupported or mal-formatted message received from x.x.x.x:
FFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFF 00BE 0200 0000 A340 0101 0040 028A 0222
0000 7D91 0000 00AE 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9
0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9
0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9 0000 21F9
0000 21F9 0000 21F9 0000 234E 0000 234E 0000 234E 0000 234E 0000 234E 0000 234E
0000 234E 0000 234E 4003 0483 6D87 01C0 0808 00AE 526D 00AE 55FC 136D 6BE0 

May 24 11:48:03: %BGP-6-ASPATH: Long AS path ....  8697 8697 8697 8697 8697 8697 8697 8697............

Paul 

[Giuseppe Larosa]

Hello Paul,

yes I agree you should see only the log message

>> May 24 11:48:03: %BGP-6-ASPATH: Long AS path .... 8697 8697 8697 8697 8697 8697 8697 8697.....

The previous lines are misleading and confusing as they make you think of a true issue with the neighbor.

By the way,  when receiving a true malformed message a BGP speaker could send a NOTIFICATION message to close the session and the session would flap.

Hope to help

Giuseppe

[paul amaral]

I thought so, good to be assured thought. Maybe cisco will patch that up. 

thanks again, 

Paul