Troubleshooting MPLS VPN

As I had promised in my post “Non-Technical Tips for CCIE Lab Troubleshooting”, I am back with a series on troubleshooting different networking technologies centering around CCIE Lab. In this post I will be talking about MPLS VPN. For an average person working in Computer Networks, MPLS seems to be a topic which seems to be most scary. Even if their project involves just an MPLS circuit between 2 locations, the word “MPLS” still scares them although there is not much difference between it and a layer 2 circuit. I have received International calls from many of my friends and colleagues who were overwhelmed by MPLS. This could stem from lack of knowledge on MPLS or the way many people teach MPLS. I have seen many guys teaching MPLS by jumping straight to configuration. This teaching method even overwhelmed me, so I tore apart MPLS VPN to understand it better and if you see the concept first and then individual protocols, it might not seem that difficult. In this post, I will not explain MPLS VPN but help develop a strategy to troubleshoot MPLS VPN. It is expected that you know MPLS beforehand to make sense of it or at least have partial knowledge. As I had mentioned in my previous blog about the disadvantages of “Show Run”, so I would be concentrating on using debugs and show commands rather than show run for troubleshooting. Continue reading

MPLS across Multiple Cities over Internet

Many articles have been written about MPLS VPN amongst different ISPs but not much information is available if there is a global ISP having PoPs across several cities in the world. In this blog, we will look into a way of providing MPLS connectivity to customers present across various cities of the world where you have point of presence. Since, the geographical location of your PoPs are diverse, your PoPs might as well be connected over the Internet. Continue reading