When faced with a troubleshooting ticket involving MPLS you need to clear the basics first to ensure that everything is working from a Label Distribution perspective. First establish IGP connectivity between all the routers. Can you ping all the loopbacks? Are there /32 loopbacks configured on every router and advertised into IGP? Is CEF enabled? [...]
MPLS VPN Configuration Example Cisco
This post will go through from start to finish the configuration required to setup a basic MPLS VPN which has 2 customers, each customer has 2 sites. The configuration is all done in GNS3. The topology I will be using is below. This MPLS tutorial will cover OSPF, LDP, MP-BGP and route redistribution. The MPLS [...]
Route Distinguisher vs Route Target – MPLS Tutorial Part 1
Route Distinguisher vs Route Target - aren’t they the same thing? No! In this post I am going to clarify the difference between route distinguisher and route target within the Cisco world of MPLS VPN’s. The main problem comes from the fact that in most Cisco Press books they always show the route distinguisher value and [...]
MPLS LDP router-id loopback0 Force
Whilst configuring an MPLS lab I came across the force option on the MPLS LDP router-id command and was not sure what it did? After reading the documentation I will now explain the MPLS LDP router-id process and the relevance of the Force option. How the LDP Router-ID is derived If the MPLS Router-ID command [...]
