CCIE Challenge 2: Troubleshoot Ticket 1
This #CCIEChallenge is a troubleshooting ticket for your pleasure. Depending on where you are in your CCIE prep you should be able to fix this ticket in 10 minutes. It would be comparable to a 3 or 4 point ticket.
The config files can be downloaded here.
R1 and R4 should be able to ping each other. Match the following output. R1 should always select its path through R3, even when R3 has suffered a failure and has returned to operations.
There are multiple separate faults in this ticket!
R1#trace 22.214.171.124 so lo0 Type escape sequence to abort. Tracing the route to 126.96.36.199 VRF info: (vrf in name/id, vrf out name/id) 1 192.168.13.3 1 msec 1 msec 1 msec 2 188.8.131.52 10 msec 3 msec 2 msec 3 184.108.40.206 [MPLS: Label 29 Exp 0] 10 msec 4 msec 10 msec 4 220.127.116.11 10 msec 8 msec 8 msec 5 192.168.46.4 14 msec * 6 msec R1#show ip bgp 18.104.22.168 [SNIP] Paths: (2 available, best #2, table default) Not advertised to any peer Refresh Epoch 1 65000 500 192.168.12.2 from 192.168.12.2 (22.214.171.124) Origin IGP, metric 0, localpref 100, valid, internal rx pathid: 0, tx pathid: 0 Refresh Epoch 2 65000 500 192.168.13.3 from 192.168.13.3 (126.96.36.199) Origin IGP, metric 0, localpref 100, valid, internal, best rx pathid: 0, tx pathid: 0x0
R4#trace 188.8.131.52 so lo0 Type escape sequence to abort. Tracing the route to 184.108.40.206 VRF info: (vrf in name/id, vrf out name/id) 1 192.168.45.5 1 msec 1 msec 1 msec 2 220.127.116.11 11 msec 1 msec 2 msec 3 18.104.22.168 [MPLS: Label 32 Exp 0] 9 msec 14 msec 5 msec 4 22.214.171.124 6 msec 13 msec 19 msec 5 192.168.12.1 10 msec * 24 msec
There are 4 faults in this ticket:
- The OSPF network type on router R12 is configured incorrectly:
interface g 0/1 ip ospf network broadcast interface g 0/0 ip ospf network broadcast
- The BGP router-id on R4 and R5 is set automatically to 126.96.36.199. This causes both routers to have the same cluster-id and ignore routes they receive from each other (even though they are not running as BGP route reflector). Can be solved by manually setting either the router-id on either router or by changing the IP address of Loopback 100 and restarting the BGP process.
R4#show ip bgp cluster-ids Global cluster-id: 188.8.131.52 (configured: 0.0.0.0) R5#show ip bgp cluster-id Global cluster-id: 184.108.40.206 (configured: 0.0.0.0)
- The cost metric set on R6 toward R12 is too high. Should be lower than R5’s metric toward R11. (Any value is good as long as its lower than 100)
route-map default permit 10 set metric 99
- R1 needs to select R3 anytime it’s available. The output must match however. This means we can’t change any regular parameter like locpref or weight because the will appear in the output. R2’s RID however is higher than R3. We can use that to select R3.
router bgp 500 bgp bestpath compare-routerid