I am dealing with a really weird problem. Currently we have the following setup:
TransitA --> RouterA TransitB --> RouterB
iBGP running btw RouterA & RouterB as well as OSPf in Area 0. We have setup a customer in Area 1 as an NSSA area on both RouterA & RouterB with identical OSPF configs like below. (I'm only including the relevant customer ospf config):
router ospf 1 area 0.0.0.1 nssa default-information-originate redistribute connected metric-type 1 subnets redistribute statis metric-type 1 subnets network 220.127.116.11 0.0.0.7 area 0.0.0.1
Now, we are advertising the customer /24's over both transit providers and the problem is that over TransitA provider, we are unable to reach the customer gear. Pings/traceroutes all stop after it hits our interface ip on RouterA while everything works perfectly fine over TransitB provider.
The other piece of information is that from the customer servers, traceroutes, etc work fine when going out over TransitA so it seems the only problem is incoming traffic being dropped over TransitA. The TransitA provider says that nothing is wrong on their end and we can't find anything wrong on our end either.
Any idea where the problem may be? Is it the ospf config, bgp, etc? If you need more info, pls let me know.
routerA#sh ip route x.x.x.x Routing entry for x.x.x.x/32 Known via "ospf 1", distance 110, metric 0, type extern 2, forward metric 1 Last update from x.x.x.x on Vlan8, 7w0d ago Routing Descriptor Blocks: * f.f.f.f, from y.y.y.y, 7w0d ago, via Vlan8 Route metric is 0, traffic share count is 1 routerB#sh ip route x.x.x.x Routing entry for x.x.x.x/32 Known via "ospf 1", distance 110, metric 0, type NSSA extern 2, forward metric 2 Last update from f.f.f.f on Vlan9, 7w0d ago Routing Descriptor Blocks: * f.f.f.f, from z.z.z.z, 7w0d ago, via Vlan9 Route metric is 0, traffic share count is 1
RouterA#sh ip route ospf | i x.x.x.x O E2 x.x.x.0/24 [110/0] via x.x.x.20, 1d00h, Vlan8 RouterA#traceroute x.x.x.c Type escape sequence to abort. Tracing the route to x.x.x.c 1 hostname.here.com (x.x.x.20) 4 msec 0 msec 0 msec 2 x.x.x.c 0 msec 0 msec 0 msec RouterB#sh ip route ospf | i x.x.x.x O N2 x.x.x.0/24 [110/0] via x.x.x.28, 1d00h, Vlan9 RouterB#traceroute x.x.x.c Type escape sequence to abort. Tracing the route to x.x.x.c 1 hostname.here.com (x.x.x.28) 0 msec 0 msec 0 msec 2 x.x.x.c 0 msec 0 msec 0 msec
So traceroutes work from both routers to the end user ip however from the internet outside, it times out over TransitA.
RouterA#ping f.f.f.f source u.u.u.u Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to f.f.f.f, timeout is 2 seconds: Packet sent with a source address of u.u.u.u !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
u.u.u.u is our interface ip that TransitA assigned to us which we have configured on one of the ports.
TransitA#traceroute x.x.x.c source y.y.y.y Type Control-c to abort Sending DNS Query to 18.104.22.168 Type Control-c to abort Tracing the route to IP node www.domain.com(x.x.x.c) from 1 to 30 hops 1 <1 ms <1 ms <1 ms host.x.com[z.z.z.z] 2 <1 ms <1 ms <1 ms srx.com [f.f.f.f] 3 <1 ms <1 ms <1 ms www.domain.com [x.x.x.c]