[j-nsp] IBGP problem

[Tim Thorne]

"Nils Kolstein" <N.Kolstein at kpn-is.nl> wrote:

>Hi,
>
>We encounter a strange problem regarding an IBGP ession between two
>M160's. Both run JunOS7.3R1.6. The IBGP session between the two stays up
>only for about 1,5 minutes after which it drops again. What I notice is
>an increase in the OutQ-value:
>
>xxx.xxx.xxx.xxx    xxxx          2        174   35413       4
>1:33 Establ
>                                              ^^^^^
>The log says:
>
>Oct 11 08:50:01 bgp_traffic_timeout: NOTIFICATION sent to
>xxx.xxx.xxx.xxx (Internal AS xxxx): code 4 (Hold Timer Expired Error),
>Reason: holdtime expired for xxx.xxx.xxx.xxx (Internal AS xxxx), socket
>buffer sndcc: 16367 rcvcc: 0 TCP state: 4, snd_una: 746157955 snd_nxt:
>746162051 snd_wnd: 57192 rcv_nxt: 2416270658 rcv_adv: 2416327867,
>keepalive timer 0
>
>This problem seemed to have popped quite sudden without any changes made
>in BGP setup or otherwise.
>
>Does anyone has a clue?

Hello,

I have a similar problem with the same version of code and some M10is.
I had graceful restart configured globally under routing options.
Turning it off stopped iBGP flapping, though it took some time to
stabilise. Its not clear that graceful restart was the problem as I
disabled it on the other peers during other maintenance sessions to no
avail. We don't normally have mtu-discovery configured per peer, but
for each of the flapping peers I had it configured this morning. Only
when I removed mtu-discovery did everything stabilise. I'm organising
another maint to look at it again. The JTAC guy I talked to this
morning thinks the problem is caused by graceful restart for OSPF.

Regards,

-- 
| Tim Thorne               Unmetered & ADSL solutions
| Network Engineer                for Home & Business
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