%IP-TCP-3-BADAUTH : Invalid MD5 digest from x.x.x.x but neighbor doesn't down

[ปลาวาฬทราย RMUTT CPE IX]

RP/0/9/CPU0:Jan 16 19:08:28 ICT: tcp[421]: %IP-TCP-3-BADAUTH : Invalid MD5 digest from x.x.228.123:179 to x.x.228.88:21012
RP/0/9/CPU0:Jan 17 15:19:11 ICT: tcp[421]: %IP-TCP-3-BADAUTH : Invalid MD5 digest from x.x.228.123:179 to x.x.228.88:21012
RP/0/9/CPU0:Jan 17 15:32:10 ICT: tcp[421]: %IP-TCP-3-BADAUTH : Invalid MD5 digest from x.x.228.123:179 to x.x.228.88:21012

RP/0/9/CPU0:Sr#sho bgp sum | inc x.x.228.123
Tue Jan 17 16:31:04.292 ICT
x.x.228.123    0 24115 17299518 1208964 550581703    0    0    14w2d      42884

How should I do?

Thank you very much.

[Aleksandar Vidakovic]

TCP retransmission takes care of resending the dropped TCP segments. This is why the BGP peer remains up despite intermittent packet loss.

If you want to troubleshoot this issue, you have to find the common point of all the observed failures, i.e. how do BGP sessions where the issue is reported differ from those where the issue is not reported: are they all established through the same line card; same interface; if the affected BGP peer have peering with other routers, do they also report invalid md5 digest; etc.

If the common point of all failures is the router on which the error is reported, you can always open a service request with Cisco TAC.