This is happening in between PE router and CE router. Immediately after configured the neighbor command on CE router, connectivity to CE router lost. Telnet management of CE router has been enabled through PE router, so whenever WAN connectivity lost management(telnet) too lost.

When check BGP neighbor table from PE router at that time, BGP neighborship was formed. Also other side(CE router) too shown neighborship is ok(this is checked by tech team by console login @ CE router side) but ping to WAN IPs not work(ping time outs). No any error message received to the router until debug the CE router for BGP. then getting attached error message.enter image description here

PE router details are: Cisco IOS XR Software, Version 5.1.3.>>asr9k-os-mbi-5.1.3.sp3-1.0.0/0x100000/mbiasr9k-rp.vm

CE router details are: "flash:c800-universalk9-mz.SPA.154-3.M3.bin"

I was trying so many things to fix this. It was noticed immidiately after remove the neighbor command from CE router again WAN connectivity is ok(ping & telnet management ok). When check BGP neighbor table it was found more than 300 prefixes on BGP table. Finally I found a way to temporally fix it by limiting BGP prefixes to very limited value(first it was 5) by using a "ip prefix-list" under the BGP process. But this is not acceptable by my customer because he need to have full routing table(all the BGP prefixes) in CE router. Please answer my question if any one had come a cross this issue previously.

  • 1
    Please include relevant configurations. – Teun Vink Mar 15 '17 at 10:20
  • 1
    You router is apparently learning the wrong routes. Please also include the routing table for the management vrf. – Ron Trunk Mar 15 '17 at 11:39
  • @TeunVink CE router router bgp 63000 bgp router-id bgp log-neighbor-changes neighbor remote-as 62000 ! address-family ipv4 network mask network redistribute connected redistribute static neighbor activate neighbor allowas-in 2 neighbor soft-reconfiguration inbound exit-address-family – Ujitha Mar 16 '17 at 12:48
  • @RonTrunk, difficul to include routing table, it is too long(more than 300 prefixes) when issue is there – Ujitha Mar 16 '17 at 12:58
  • Check your routes to your management devices. That's where the problem likely lies. – Ron Trunk Mar 16 '17 at 13:18

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