06-23-2010 11:07 AM - edited 03-04-2019 08:52 AM
when issuing sh ip bgp neigh <IP> i am getting header sync problems and the peering stays IDLE - see below for output
Any help is appreciated before logging a TAC case :-)
RP/0/RP1/CPU0:ND-NEO-RCRS1-ISP-DMZ-R1C11#sh ip bgp neig 192.168.32.18
Tue Jun 22 17:10:03.580 GMT
BGP neighbor is 192.168.32.18
Remote AS 37168, local AS 37168, internal link
Description: IBGP_Esher_Neotel
Remote router ID 0.0.0.0
Cluster ID 10
BGP state = Connect
Last read 00:00:03, hold time is 180, keepalive interval is 60 seconds
Configured hold time: 180, keepalive: 60, min acceptable hold time: 3
Last write 00:01:26, Last write before reset 00:01:43
Last write pulse rcvd Jun 22 17:09:47.913 last full not set pulse count 4
Socket not armed for io, armed for read, armed for write
Precedence: internet
Received 0 messages, 0 notifications, 0 in queue
Sent 3 messages, 2 notifications, 0 in queue
Minimum time between advertisement runs is 0 secs
For Address Family: IPv4 Unicast
BGP neighbor version 0
Update group: 0.2
Route-Reflector Client
Inbound soft reconfiguration allowed
Route refresh request: received 0, sent 0
0 accepted prefixes, 0 are bestpaths
Prefix advertised 0, suppressed 0, withdrawn 0, maximum limit 524288
Threshold for warning message 75%
An EoR was not received during read-only mode
Last ack version 1, Last synced ack version 0
Outstanding version objects: current 0, max 0
Connections established 0; dropped 0
Last reset 00:01:26, due to BGP Notification sent: header synchronization problems
Time since last notification sent to neighbor: 00:01:26
06-23-2010 12:47 PM
Hello,
What IGP are you using? This is generally related to ISIS.
If its is ISIS, have you made any adjustments to ISIS packet headers (turning off hello padding, changing hello-interval, etc)? Try removing any tweaks you have made.
Also try clearing the TCP session with the TCB address.
http://www.cisco.com/en/US/docs/ios/11_3/configfun/command/reference/frconban.html#wp2958
Also, what hardware are you using? Please attach configs so we can see the full picture.
HTH.
Joe.
06-24-2010 12:32 PM
Hello S-Vanjaarsveld,
what IOS XR version is running on this CRS-1 router?
the session is not established since 1h and 26 minutes and peer BGP router-id is 0.0.0.0.
All this points to a problem at the TCP or BGP level.
>> Route-Reflector Client
the other device is configured as route-reflector-client may you check if the other device is not considering this CRS-1 node a route-reflector client too?
>> Last reset 00:01:26, due to BGP Notification sent: header synchronization problems
this looks like it had received a TCP segment with unexpected sequence number or Ack number.
follow Joe's suggestions you can also start by resetting the BGP neighbor with clear ip bgp neigh OR clear bgp neigh (being this IOS XR)
Hope to help
Giuseppe
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