BGP session not established

[rwakagabo]

Hello Dears

kindly assist on possible cause on below BGP issue. BGP session failed to be established with below error

name   proto   table     state   since           info
XXX     BGP   master   start   10:23:26     Idle Received: Malformed AS_PATH

and 

V    AS       MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

 4  XXX           0           0           0        0      0        never      Active

i am able to ping the IP of peer.

Best regards

Janvier R.

[Julio E. Moisa]

Hi Javier

It means that BGP is trying to establish the TCP three way handshake in order to complete the connection with the neighbor.

Just some questions:

- Was it working properly before?
- Any change was implemented recently?
- Have you implemented any ACL blocking the port TCP 179 on one of these devices?
- Is this an eBGP or iBGP connection?

Could you please share the BGP configuration of these peers?

Thank you

[rwakagabo]

hi Julio

Thanks for the reply.

-The session was established before but suddenly it is stopped.

-no change done on my side

-no ACL implemented blocking port 179

-it is an eBGP connection

find BGP configurations of peer

neighbor IP ADD remote-as XXXX
neighbor IP ADD peer-group ixp-peers
neighbor IP ADD description YYYYY

Thank you!!!

Janvier R.

[Julio E. Moisa]

Thank you

Are you using the directly connected subnet to create the eBGP peering?