i still newbie to configure eBGP, i have Router 3600 series, and i configure BGP neighbor to my ISP, but the peer still don't established,
there is warning like this,
Connections established 339; dropped 339
"Last reset 2w4d, due to Peer closed the session
No active TCP connection"
any one can explain to me about "due to Peer closed the session " ?
i've read some documents for troubleshooting BGP, and do some step to troubleshoot, but
i still don't get solution. please help.
Hi Reza thanks for your reply,
here is my simple BGP config :
router bgp xxxxx
bgp router-id x.x.x.x
neighbor x.x.x.x remote-as yyyyy
neighbor x.x.x.x description ISP
neighbor x.x.x.x soft-reconfiguration inbound
neighbor x.x.x.x distribute-list TDS-OUT out
neighbor x.x.x.x route-map ISP-IN in
neighbor x.x.x.x route-map NAP-IN out
ip as-path access-list 2 permit ^yyyyy_[0-9]*$
route-map NAP-IN permit 10
match as-path 2
please help Reza
Can you please ping the BGP neighbor IP Address with the repeat count for 1000 and check how many drops you are getting there.
If there are too many drops, then your neighborship is getting dropped due to crappy link.
IMHO, if you are able to Ping the neighbor router, you should contact your ISP and ask why their router is closing the BGP session.
There might be several reasons:
Incorrect AS number configured on your side, BGP session password expected, maximum number of prefixes advertised exceeded, etc.
I've personally seen the last one in my network some time ago:
You might try to reconfigure your router to send just one prefix to the ISP and reset the BGP peering by "clear ip bgp nei x.x.x.x".
If the BGP session keeps Up then, you know the root problem cause probably.
As per Ahmad's logs, we can see that BGP session is getting established and then getting dropped, so that we can safely assume that issue is not with incorrect AS number configuration and neither BGP session password; as if these would be incorrect, BGP won't be establishing in first place.
However, prefix-limit reach can be one possible issue.
But, I wanted him (Ahmad) to rule out physical layer issue first (that why i suggested to check the ping response and see how many packets are getting dropped) and then move to upward layer issues.
Message was edited by: smitesh kharecha
i agree with smitesh. first make sure there is no packet loss n latency. try different mtu sizes as well.
also check the interface " sh int
also check with ip if they made any changes at their end?
thanks so much for your reply,
1. i try to ping like smitesh said, the result is good i think, 999/1000
2. also i try to use different MTU like kishore said, then still good, also i check again my interface, no problem
3. i consider what simtesh said about prefix-limit issue, sorry for all, i forgot to tell you that my Router is 3600 with 64 MB memory only, is it has many affect (with my as-path config) ?
please your suggestion
Are you receiving full routing table or just default route from your ISP ?
If it is continuous flapping, then can you please provide us outputs of following commands:
debug ip bgp updates
debug ip bgp event
IMHO, if it were your router lack of memory problem, you would see some error messages in your syslog.
Additionally to Smitesh's question:
How many prefixes are you sending to the ISP? (Possibly too many?)
Have you asked the ISP why their router is closing the BGP session?
sorry i couldn't go to debug command (i use telnet), oh yeah how to know number of prefixes which i sent to my ISP, as you know from my config above, i use prefix scheme that i got from cisco tutorial (http://www.cisco.com/en/US/partner/tech/tk365/technologies_tech_note09186a0080094a83.shtml),
then if prefix number is the main issue, please give me some help how to config use minimum prefix to my ISP,
and Mr. smittesh i didn't use default route, but i use prefix scenario from tutorial above.
sorry, i strongly need your help
Can you please provide the output of following commands
show ip bgp neighbor
show ip bgp neighbor
show ip bgp summary
Also, you need to check with your ISP whether they have put any prefix-limit to your connection.
thanks for your help
here is the result of show command :
JKT1#sh ip bgp neighbors x.x.x.x received-routes
JKT1#sh ip bgp neighbors x.x.x.x advertised-routes
JKT1#sh ip bgp summary
BGP router identifier A.A.A.A, local AS number BBBBB
BGP table version is 111680, main routing table version 111680
7816 network entries using 758152 bytes of memory
7816 path entries using 281376 bytes of memory
516 BGP path attribute entries using 30960 bytes of memory
460 BGP AS-PATH entries using 11252 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1081740 total bytes of memory
BGP activity 50865/43049 prefixes, 57369/49553 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRc
z.z.z.z 4 BBBBB 0 0 0 0 0 never Active
x.x.x.x 4 CCCC 0 0 0 0 0 never Active
y.y.y.y 4 DDDD 38606 25636 111680 0 0 2w3d 7808
as you see above, i have 2 link2 (multi) neighbors y.y.y.y was my domestic route and it's work, but the problem peer was x.x.x.x, which were discuss point.
please don't bored helping me
Hi all, sorry i've been some job to do,
i've tried use any scenario, such as only receive default route from ISP, and receive only Directly-Connected Routes,
but still the error was "not enough memory", is there any config to not receive any routes from ISP, so i just use default route to the ISP?
neighbor x.x.x.x route-map ISP-IN in
route-map ISP-IN deny 10
This way you will not accept any prefix from your neighbor.
But so far you did not mention any "not enough memory" error messages on your router?