nanog mailing list archives
Re: BGP neighbor/configuration testing
From: Chuck Anderson <cra () WPI EDU>
Date: Mon, 25 Nov 2013 18:37:49 -0500
When you say "no logged error" with mismatched neighbor IP address, what do you mean? Did the session just not establish at all? How long did you wait for it to attempt to establish? On Juniper, if it sees a BGP connection come from an IP address that doesn't match a local "neighbor" statement, it will send a BGP Notification, code 2 (Open Message Error), subcode 5 (authentication failure), which is exactly what you are seeing. If one side is using a loopback IP instead of a physical IP for the local-address, that would cause both a multihop/TTL issue and a neighbor IP mismatch. Another possibility is if you have exceeded the max prefix limit for the session. One side will get stuck in Idle state which may cause the other side to send the same "authentication failure" notification. On Mon, Nov 25, 2013 at 03:07:28PM -0800, Eric A Louie wrote:
All Cisco/Cisco, I don't have a Juniper here to test with mismatch AS *AprĀ 9 00:31:47.691: %BGP-3-NOTIFICATION: received from neighbor 10.250.254.253 2/2 (peer in wrong AS) 2 bytes 6A39 mismatch neighbor IP address no logged error MTU mismatch no logged error, session remained up Subnet mask mismatch session remained up, no logged error I haven't created the multihop scenario to see the error messages. None of these issues caused the (authentication failure).________________________________ From: Chuck Anderson <cra () WPI EDU> To: nanog () nanog org Sent: Monday, November 25, 2013 11:10 AM Subject: Re: BGP neighbor/configuration testing Authentication failure might mean (without knowing for sure which on Cisco): - mismatch AS numbers - mismatch neighbor IP addresses - multihop/TTL issues - MTU issues
Current thread:
- BGP neighbor/configuration testing Eric A Louie (Nov 20)
- Re: BGP neighbor/configuration testing Joe Abley (Nov 20)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 25)
- Re: BGP neighbor/configuration testing Daniel Rohan (Nov 25)
- RE: BGP neighbor/configuration testing John Stuppi (jstuppi) (Nov 25)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 25)
- Re: BGP neighbor/configuration testing Chuck Anderson (Nov 25)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 25)
- Re: BGP neighbor/configuration testing Pedro Cavaca (Nov 25)
- Re: BGP neighbor/configuration testing Chuck Anderson (Nov 25)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 25)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 26)
- Re: BGP neighbor/configuration testing Eric A Louie (Nov 25)
- Re: BGP neighbor/configuration testing Joe Abley (Nov 20)