Are this routes all running in the ospf and bgp at the same time? If yes, it is a normal behaviour.
Thanks and regards, Xu Hu On 8 Aug, 2012, at 22:27, Sebastian Wiesinger <[email protected]> wrote: > Hello, > > I'm having a strange problem with a Cisco 6500/SUP720 running > 12.2(33)SXJ3. > > Currently we're testing this router in the lab. We have one OSPF > connection to the outside and iBGP enabled. > > As soon as I enable the iBGP i get really strange effects: > > I have 10.1.66.0/25 connected to a SVI (Vlan412) and all IPs are > terminated on one server for testing. > > Now when I ping some IPs I get a normal answer: > > > $ ping 10.1.66.51 > PING 10.1.66.51 (10.1.66.51) 56(84) bytes of data. > 64 bytes from 10.1.66.51: icmp_req=1 ttl=60 time=3.88 ms > 64 bytes from 10.1.66.51: icmp_req=2 ttl=60 time=3.91 ms > > And now the problem: > > $ ping 10.1.66.84 > PING 10.1.66.84 (10.1.66.84) 56(84) bytes of data. > From 10.2.14.9 icmp_seq=1 Time to live exceeded > From 10.2.14.9 icmp_seq=2 Time to live exceeded > From 10.2.14.9 icmp_seq=3 Time to live exceeded > > A traceroute shows the packet is looping, the lab router is sending it > back to it's OSPF peer (instead of sending it out through Vl412) who > sends it straight back: > > 5 10.2.14.10 4.592 ms 4.561 ms 4.575 ms > 6 10.2.14.9 4.996 ms 4.162 ms 4.240 ms > 7 10.2.14.10 4.204 ms 4.135 ms 4.156 ms > 8 10.2.14.9 4.273 ms 4.193 ms 4.106 ms > 9 10.2.14.10 4.015 ms 4.237 ms 4.156 ms > ... > > Issuing various commands I can see no difference between the two IPs > on the router: > > lab-rtr1#show ip route 10.1.66.51 > Routing entry for 10.1.66.0/25 > Known via "connected", distance 0, metric 0 (connected, via interface) > Routing Descriptor Blocks: > * directly connected, via Vlan412 > Route metric is 0, traffic share count is 1 > > lab-rtr1#show ip route 10.1.66.84 > Routing entry for 10.1.66.0/25 > Known via "connected", distance 0, metric 0 (connected, via interface) > Routing Descriptor Blocks: > * directly connected, via Vlan412 > Route metric is 0, traffic share count is 1 > > > CEF entries: > > > lab-rtr1#show ip cef adjacency Vlan412 10.1.66.51 internal > IPv4 CEF is enabled for distributed and running > VRF base: > 64739 prefixes (64737/2 fwd/non-fwd) > Default network 0.0.0.0/0 > Table id 0 > Database epoch: 7 (64739 entries at this epoch) > > 10.1.66.51/32, epoch 7, flags attached, refcount 4, per-destination sharing > sources: Adj > feature space: > NetFlow: Origin AS 0, Peer AS 0, Mask Bits 25 > subblocks: > Adj source: IP adj out of Vlan412, addr 10.1.66.51 5136EEC0 > Dependent covered prefix type adjfib cover 10.1.66.0/25 > ifnums: > Vlan412(180): 10.1.66.51 > path 5110F968, path list 5110C090, share 1/1, type adjacency prefix, for IPv4 > attached to Vlan412, adjacency IP adj out of Vlan412, addr 10.1.66.51 > 5136EEC0 > output chain: IP adj out of Vlan412, addr 10.1.66.51 5136EEC0 > > lab-rtr1#show ip cef adjacency Vlan412 10.1.66.84 internal > IPv4 CEF is enabled for distributed and running > VRF base: > 64739 prefixes (64737/2 fwd/non-fwd) > Default network 0.0.0.0/0 > Table id 0 > Database epoch: 7 (64739 entries at this epoch) > > 10.1.66.84/32, epoch 7, flags attached, refcount 4, per-destination sharing > sources: Adj > feature space: > NetFlow: Origin AS 0, Peer AS 0, Mask Bits 25 > subblocks: > Adj source: IP adj out of Vlan412, addr 10.1.66.84 5136A6C0 > Dependent covered prefix type adjfib cover 10.1.66.0/25 > ifnums: > Vlan412(180): 10.1.66.84 > path 51110C70, path list 5110D2F8, share 1/1, type adjacency prefix, for IPv4 > attached to Vlan412, adjacency IP adj out of Vlan412, addr 10.1.66.84 > 5136A6C0 > output chain: IP adj out of Vlan412, addr 10.1.66.84 5136A6C0 > > This is totally random. When I shut/no shut the SVI the problem goes > away and comes back soon after but on different IPs. > > Clearing the CEF table has the same effect. > > When I shut down BGP the problem seems to go away. > > Also BGP sessions are flapping from time to time without apparent > reason. > > Any idea what can cause this? > > Next steps include switching to the other Supervisor installed and/or > downgrade IOS. > > Regards > > Sebastian > > > -- > GPG Key: 0x93A0B9CE (F4F6 B1A3 866B 26E9 450A 9D82 58A2 D94A 93A0 B9CE) > 'Are you Death?' ... IT'S THE SCYTHE, ISN'T IT? PEOPLE ALWAYS NOTICE THE > SCYTHE. > -- Terry Pratchett, The Fifth Elephant > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
