I encountered a weird BGP session problem. The eBGP neighbor status always stay idle, regardless clear ip bgp or re-configure eBGP. The network connectivity to EBGP neighbor is no problem, it is pingable and no packet loss. I enabled TCP and BGP debug, can not see router change the neighbor status from idle to active to initiate BGP session. Only see some TCP reset send to neighbor to refuse neighbor initiate BGP TCP connection.
The router platform is C7206, IOS:Version 12.3(7)T1
router bgp yyy
neighbor x.x.x.10 remote-as xxx
neighbor x.x.x.10 version 4
neighbor x.x.x.10 soft-reconfiguration inbound
neighbor x.x.x.10 route-map import in
neighbor x.x.x.10 route-map export out
x.x.x.10 4 xxx 0 0 0 0 0 never Idle
Mar 10 15:17:18: TCP: sending RST, seq 0, ack 3575773935
Mar 10 15:17:18: TCP: sent RST to x.x.x.10:60738 from x.x.x.38:179
Mar 10 15:23:37: TCP: sending RST, seq 0, ack 2383734249
Mar 10 15:23:37: TCP: sent RST to x.x.x.10:56981 from x.x.x.38:179
Mar 10 15:26:05: TCP: sending RST, seq 0, ack 989447100
Mar 10 15:26:05: TCP: sent RST to x.x.x.10:63386 from x.x.x.38:179
Can someone tell me how to change the BGP status from idle to active to accept/initiate TCP connection? How to troubleshooting next?
Any comment is very appreciate.
first of all it has been kind of you to have provided feedaback.
To be noted that to upgrade IOS you need to perform a full reload that could have fixed the problem.
Hope to help