different BGP session behavior 12.6->15.3?

[EtherNation_Use]

Create Date: Feb 28 2013 8:38PM

Hi all,

I recently tried upgrading one of our core X480 routers from 12.6.3-patch1-8 to 15.3.1 as we're hoping to turn up IPv6 BGP soon. The switch is peered with another X480 inside our AS, running 12.6, and an ISP router, which is a Juniper. The IBGP session came up just fine, but the EBGP session with the Juniper came up, exchanged routes, and was shut down from the Juniper side, with an "optional attributes error." The session gets reset, and eventually the cycle repeats. Traffic flows, but the resets cause our routes to flap through that ISP, causing connectivity issues. The ISP has opened a ticket with Juniper to see what might be causing this, but has anyone seen behavior like this in moving from 12.6 to 15.3? Is there a different set of standard behavior with BGP sessions in 15.3?

Anonymized config follows. Route policy "ISPOut" referenced below restricts our exported routes to our NLRI, matching exactly.

enable bgp address-family ipv4-unicast advertise-inactive-route
configure bgp AS-number 65000
configure bgp routerid 192.168.1.2
configure bgp maximum-paths 4
enable bgp community format AS-number:number
configure bgp restart aware-only
configure bgp add network 192.168.1.0/22
create bgp neighbor 10.10.10.5 remote-AS-number 65001
configure bgp neighbor 10.10.10.5 source-interface ipaddress 10.10.10.6
configure bgp neighbor 10.10.10.5 password encrypted "blahblahblah"
configure bgp neighbor 10.10.10.5 description "ISP BGP Peer"
create bgp neighbor 192.168.1.1 remote-AS-number 65000
configure bgp neighbor 192.168.1.1 source-interface ipaddress 192.168.1.2
configure bgp neighbor 192.168.1.1 password encrypted "blahblahblah"
enable bgp neighbor 192.168.1.1
configure bgp neighbor 10.10.10.5 next-hop-self
configure bgp neighbor 10.10.10.5 route-policy out ISPOut
disable bgp neighbor 10.10.10.5 capability ipv4-multicast
configure bgp neighbor 192.168.1.1 send-community standard
disable bgp neighbor 192.168.1.1 capability ipv4-multicast
(from Ansley_Barnes)

[EtherNation_Use]

Create Date: Mar 11 2013 1:42PM

I just went to download it, actually, but there's no SSH image download link (policy prevents us from managing via unencrypted protocols) and the release notes link points, inexplicably, to the release notes for 12.3.1... I'm installing 15.1.4 right now to test the fix. (from Ansley_Barnes)

[EtherNation_Use]

Create Date: Mar 11 2013 1:30PM

15.2.3 is released now. You can try it. Let us know how it goes. (from ethernet)

[EtherNation_Use]

Create Date: Mar 11 2013 12:06AM

Interesting - are you sure? It did accept the command to ignore the AS 0 with aggregate set properly, and it seems odd that the command would be added without the fix. I will try a further rollback to the confirmed fixed version tomorrow. (from Ansley_Barnes)

[EtherNation_Use]

Create Date: Mar 9 2013 9:31AM

I was told that was a typo in the release notes in 15.2.2.7 patch 1-6. you have to wait for 15.2.3 to apply the configuration change effectively. (from ethernet)

[EtherNation_Use]

Create Date: Mar 9 2013 2:31AM

I applied 15.2.2.7patch1-6, as I checked the release notes and it had the fix for # PD4-3298430801. I ran the command, and restarted the BGP session, but still am getting the Optional Attribute error. We've temporarily changed our NLRI filter to distribute no routes, so we have a bit more flexibility in testing solutions.

I'm really scratching my head here though - was there any other behavior changed for ipv4-unicast BGP sessions in 15.x? (from Ansley_Barnes)