Friday, June 17, 2011

MPLS Layer 3 VPN Troubleshooting - My Personal Approach

While I am going for my Second CCIE R&S Lab attempt soon, I thought before leaving I must post my MPLS TS Strategy in general despite of fact I will get in my TS lab or not :

Ofcourse people who wanna know what went wrong with First attempt, here is the summary :

Below are the summary steps:

Step 1


CEF is running on MPLS enabled routers

sh ip cef

Step 2

loopback advertised into IGP on CE, Also Check IGP configuration like "no auto summary" and "redistribution seed metric, "autonomous system number in EIGRP VRF Configuration".

sh ip int b | e una

sh run | s r [eor]

Step 3

Check if VRF is created and applied to proper interface

sh run | s vrf

sh ip vrf detail

sh run int

Check if CE routes are coming to PE

sh ip route vrf

Step 4

Check for VRF route target import and export

sh run | s vrf

Step 5

Check if LDP is running all over, mpls ip is configured on MPLS facing interfaces.

sh mpls interface

sh mpls ldp neighbor

Step 6

Check for MP-BGP and IGP redistribution,

sh run | s r b

sh run | s r [reo]

Check for redistribute metric, For OSPF look for "match internal external 1 external 2" , For eigrp "redistribution metric" should be mentioned.

Step 7

Check for MPBGP Config on all routers, look for things like RR config, neighbor activate, send community extended or both, no synchronization, no auto summary, remote as, update source loopback 0

sh run | s r b

sh ip bgp vpnv4 all summ

sh ip bgp vpnv4 all

Step 8

Check for Control plane issues on all routers like:

1. ACL

sh access-list

2. CoPP

sh policy-map control-plane

3. Distribute List, Offset-List

sh run | i distribute offset

4. Route-map

sh route-map

5. Rate Limit

sh run | i rate

6. Next Hop and Route Recursion Issues

7. IGP Timers and Password mistmatch issues

8. PBR

sh run | i policy

Deepak Arora


Anonymous said...

Very good steps for MPLS troubleshooting...!!!

Anonymous said...

Very good steps for MPLS Troubleshooting...!!!

ram said...

Very good steps for MPLS Troubleshooting..!!!

Anonymous said...

Very good steps for MPLS Troubleshooting..!!!