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

Non-Technical Tips for CCIE Lab Troubleshooting

With the introduction of Troubleshooting section in CCIE Lab Routing and Switching, getting the CCIE number has become ever so difficult. I have even come across people who have switched to other CCIEs like Security, Voice, etc because clearing Troubleshooting section was beyond them. The other problem with TS is that it is placed before the Lab exam, so if you think that you will not be able to clear TS Section, you will have absolutely no interest in completing the configuration portion. The disadvantage to this is that you will lose the free attempt to practice configuration section which would be helpful in future attempts.

In this blog I will write about the Non-Technical aspects which might help you in clearing the TS Section. There are several things you must know before you attempt the TS Section, during the preparation for it, before attempting it and during the attempt. These inputs are based on my experience and could differ from people to people. Continue reading

Cisco AAA and how to get Locked Out

Cisco AAA is a very important security tool to restrict access to your network equipments to only those who are Network administrators. It is an important topic for CCIE Lab and in real life as well. The problem with Network Security is that sometimes due to human error, the network gets so secured that even the Network Administrator does not get access to the equipments. To make such a mistake is very easy because not many people know what exactly goes on after enabling AAA. In this blog, we will look into ways of enabling AAA and possible ways to get out of lock out if there was a proper exit strategy. Continue reading