nothing out of the norm, i will try in a few minutes to take the link down and snap a view though
thanks On Tue, Jul 22, 2008 at 8:06 AM, Ozgur Guler <[EMAIL PROTECTED]> wrote: > When you do "show ip bgp nei detail" while the sessions are flapping, > Do you see anything wrong in the TCP parameters? > I remember a bug in 12.0S where TCP window size becomes 0 for BGP causing > it to flap. Or if it is an MTU problem you might see that the BGP Keepalives > are being throttled. > > --- On *Tue, 22/7/08, Christian Koch <[EMAIL PROTECTED]>* wrote: > > From: Christian Koch <[EMAIL PROTECTED]> > Subject: Re: [c-nsp] BGP Hold Time Expired, but why? > To: "Ozgur Guler" <[EMAIL PROTECTED]> > Cc: "Oliver Boehmer (oboehmer)" <[EMAIL PROTECTED]>, "cisco-nsp" < > [email protected]> > Date: Tuesday, 22 July, 2008, 12:54 PM > > > they are all 7609-S > > On Tue, Jul 22, 2008 at 5:25 AM, Ozgur Guler <[EMAIL PROTECTED]> > wrote: > >> Is this a GSR? >> >> >> >> --- On *Tue, 22/7/08, Christian Koch <[EMAIL PROTECTED]>* wrote: >> >> From: Christian Koch <[EMAIL PROTECTED]> >> Subject: Re: [c-nsp] BGP Hold Time Expired, but why? >> To: "Oliver Boehmer (oboehmer)" <[EMAIL PROTECTED]> >> Cc: "cisco-nsp" <[email protected]> >> Date: Tuesday, 22 July, 2008, 1:58 AM >> >> >> same issue, no differences...got me >> >> >> >> >> >> On Sun, Jul 20, 2008 at 2:53 AM, Oliver Boehmer (oboehmer) < >> [EMAIL PROTECTED]> wrote: >> >> > I don't know, but I would try it.. Looks weird.. >> >> > >> > oli >> > >> > ------------------------------ >> > *From:* Christian Koch [mailto:[EMAIL PROTECTED] >> > *Sent:* >> Saturday, July 19, 2008 7:07 PM >> > >> > *To:* Oliver Boehmer (oboehmer) >> > *Cc:* cisco-nsp >> > *Subject:* Re: [c-nsp] BGP Hold Time Expired, but why? >> > >> > config look ok as far as i can see, i >> actually dont have bgp router-id >> >> > set in the bgp config... you think if i add that with the loopback ip, it >> > would make a difference? >> > >> > >> > config >> > >> > router bgp 65000 >> > no synchronization >> > bgp log-neighbor-changes >> >> > bgp graceful-restart restart-time 120 >> > bgp graceful-restart stalepath-time 360 >> > bgp graceful-restart >> > bgp dampening >> > neighbor Backbone peer-group >> > neighbor Backbone remote-as 65000 >> >> > neighbor Backbone update-source Loopback1 >> > neighbor Backbone version 4 >> > neighbor Backbone send-community >> > neighbor 10.10.10.2 peer-group Backbone >> >> > neighbor 10.10.10.3 peer-group Backbone >> > no >> auto-summary >> > >> > >> > >> > >> > >> > On Sat, Jul >> 19, 2008 at 12:29 PM, Oliver Boehmer (oboehmer) < >> > [EMAIL PROTECTED]> wrote: >> >> > >> >> Hmm, "%BGP-5-ADJCHANGE: neighbor 10.10.10.3 Down BGP protocol >> >> initialization" looks unexpected, not sure what's happening.. >> >> just a hunch, but can you double-check your config regarding loopback >> >> >> addresses, bgp router-id and things? Possibly add some bgp debug (deb >> >> bgp all events, deb bgp all, deb bgp all keep) and see if something >> >> weird pops up? >> >> What does the neighbor's (10.10.10.3) log say? >> >> >> >> >> oli >> >> >> >> ________________________________ >> >> >> >> From: Christian Koch [mailto:[EMAIL PROTECTED] >> >> >> Sent: Saturday, July 19, 2008 3:08 PM >> >> To: Oliver Boehmer (oboehmer) >> >> Cc: cisco-nsp >> >> Subject: Re: [c-nsp] >> BGP Hold Time Expired, but why? >> >> >> >> >> >> hmm, i didnt check cef/mpls on the new path, i should try that.. there >> >> is connectivity between the loopbacks >> >> >> >> the session comes back up right after the timer expires.thats what >> >> >> puzzles me >> >> >> >> actually 3-4 is about how long i kept it down for.. >> >> >> >> >> >> Jul 16 14:29:22 EDT: %LINK-3-UPDOWN: Interface TenGigabitEthernet2/2, >> >> changed state to down >> >> >> Jul 16 14:29:22 EDT: %LINEPROTO-SP-5-UPDOWN: Line protocol on >> Interface >> >> TenGigabitEthernet2/2, changed state to down >> >> Jul 16 14:29:22 EDT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on >> >> >> TenGigabitEthernet2/2 from FULL to DOWN, Neighbor Down: Interface down >> >> or detached >> >> Jul 16 14:29:22 EDT: %LDP-5-NBRCHG: LDP Neighbor 10.10.10.2:0 (11) is >> >> >> DOWN (Interface not >> operational) >> >> Jul 16 14:29:22 EDT: %LINK-SP-3-UPDOWN: Interface >> TenGigabitEthernet2/2, >> >> changed state to down >> >> Jul 16 14:29:23 EDT: %LINK-SP-3-UPDOWN: Interface >> TenGigabitEthernet2/2, >> >> >> changed state to up >> >> Jul 16 14:29:23 EDT: %LINK-3-UPDOWN: Interface TenGigabitEthernet2/2, >> >> changed state to up >> >> Jul 16 14:29:23 EDT: %LINEPROTO-5-UPDOWN: Line protocol on Interface >> >> >> TenGigabitEthernet2/2, changed state to up >> >> Jul 16 14:29:23 EDT: %LINEPROTO-SP-5-UPDOWN: Line protocol >> on >> Interface >> >> TenGigabitEthernet2/2, changed state to up >> >> Jul 16 14:29:33 EDT: %LDP-5-NBRCHG: LDP Neighbor 10.10.10.2:0 (11) is >> >> UP >> >> Jul 16 14:30:19 EDT: %OSPF-5-ADJCHG: Process 10, Nbr 10.10.10.2 on >> >> TenGigabitEthernet2/2 from LOADING to FULL, Loading Done >> >> Jul 16 14:30:37 EDT: %LDP-5-NBRCHG: LDP Neighbor 10.10.10.2:0 (4) >> is >> >> DOWN (Discovery Hello Hold Timer expired) >> >> Jul 16 14:31:39 EDT: %LDP-5-NBRCHG: LDP Neighbor 10.10.10.2:0 (4) is >> UP >> >> Jul 16 14:32:38 EDT: %BGP-3-NOTIFICATION: received from neighbor >> >> >> 10.10.10.3 >> 4/0 (hold time expired) 0 bytes >> >> Jul 16 14:32:38 EDT: %BGP-5-ADJCHANGE: neighbor 10.10.10.3 Down BGP >> >> >> protocol initialization >> >> Jul 16 14:32:45 EDT: %BGP-5-ADJCHANGE: neighbor 10.10.10.3 Up >> >> >> >> >> >> >> >> On Sat, Jul 19, 2008 at 3:24 AM, Oliver Boehmer (oboehmer) >> >> >> <[EMAIL PROTECTED]> wrote: >> >> >> >> >> >> No clue what's happening.. I've seen issues in the past >> with TCP >> >> >> PMTUD >> >> when the path converges over a link with a different MTU (which >> >> is >> >> happening in your case), but as BGP will not send packets >> larger >> >> than >> >> >> 4k, this shouldn't be an >> issue here. >> >> >> >> How long did you take down the link before bringing it back up? >> >> I assume >> >> longer than 3 minutes? Have you checked CEF and MPLS along the >> >> >> new path? >> >> You have IP connectivity between the loopbacks aR1 and bR2? >> Does >> >> the >> >> session come back up eventually, or will it stay down? >> >> >> >> oli >> >> >> >> >> Christian Koch <> wrote on Saturday, July 19, 2008 8:38 >> AM: >> >> >> >> >> >> > sorry forgot to specify >> >> > >> >> > the bgp session from aR1 to bR2 is the session in question >> >> >> > >> >> > ck >> >> > >> >> > On Sat, Jul 19, 2008 at 2:21 AM, Christian Koch >> >> > <[EMAIL PROTECTED]> >> wrote: >> >> > >> >> >> Hello - >> >> >> >> >> >> I have the following topology in lab, testing >> different >> >> failure >> >> >> scenarios. When i disconnect the link between aR1 and >> >> bR1, >> >> what >> >> >> would appear to be normal happens - ospf and ldp >> neighbor go >> >> down. >> >> >> >> >> >> When i re-connect the link between aR1 and bR1, the >> >> interface >> >> comes >> >> >> back up, osfp/ldp neighbor is re-established. >> >> >> >> >> >> 3minutes later, bgp holdtime expires , and all links >> are up.. >> >> >> >> >> >> >> aR1-----------------bR1 >> >> >>> >> | >> >> >>> | >> >> >> >>> | >> >> >>> | aR2-----------------bR2 >> >> >> >> >> >> >> >> >> Some Notes >> >> >> >> - All Links 10GE >> >> >> - Full ibgp mesh >> >> >> - Peering is to loopbacks >> >> >> - OSPF as IGP >> >> >> - Loopbacks in OSPF >> >> >> >> - MPLS Enabled on Interfaces >> >> >> >> >> >> >> >> >> OSPF cost between aR1 and aR2 is 1 >> >> >> OSPF cost between bR1 and bR2 is 1 >> >> >> >> OSPF cost between aR1 and bR1 is 250 >> >> >> OSPF cost betwen aR2 and bR2 is 500 >> >> >> >> >> >> >> MTU 9216 between aR1 and aR2, aR1 and bR1, aR2 AND BR2 >> >> >> >> MTU 9182 >> between bR1 and bR2 >> >> >> >> >> >> >> >> >> IOS on aR1 and aR2 is 12.2.33.SRB2 - SUP720 >> >> >> IOS on bR1 and bR2 is 12.33.SRC - RSP720 >> >> >> >> >> >> >> >> >> >> i am stumped, any ideas would be helpful in trying to >> >> understand why >> >> >> the bgp session is going down due to expired hold >> >> time, when >> >> all >> >> >> links are up.. >> >> >> >> >> >> thanks! >> >> >> >> >> >> ck >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> > >> >> > >> >> > -- >> >> > ^christian$ >> >> >> >> >> >> > _______________________________________________ >> >> > cisco-nsp mailing list [email protected] >> >> > https://puck.nether.net/mailman/listinfo/cisco-nsp >> >> >> > archive at http://puck.nether.net/pipermail/cisco-nsp/ >> >> >> >> >> >> >> >> >> >> >> >> -- >> >> >> ^christian$ >> >> >> > >> > >> _______________________________________________ >> cisco-nsp mailing list [email protected] >> https://puck.nether.net/mailman/listinfo/cisco-nsp >> >> archive at http://puck.nether.net/pipermail/cisco-nsp/ >> >> >> ------------------------------ >> Not happy with your email address? >> Get the one you really want <http://uk.docs.yahoo.com/ymail/new.html> - >> millions of new email addresses available now at >> Yahoo!<http://uk.docs.yahoo.com/ymail/new.html> >> > > > ------------------------------ > Not happy with your email address? > Get the one you really want <http://uk.docs.yahoo.com/ymail/new.html> - > millions of new email addresses available now at > Yahoo!<http://uk.docs.yahoo.com/ymail/new.html> > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
