CCIE R&S V4.0 Troubleshooting GNS3 Lab 1

Hi Everyone,

It is my pleasure to announce that I am publishing the first CCIE R&S V4.0 GNS3 TS lab in this post. I would first like to apologize for the delay. I know that many people have been waiting for this, so here you are.

CCIE R&S Troubleshooting GNS3 Labs soon available

I will soon publish 5 Troubleshooting CCIE R&S Labs based on INE GNS3 Lab1 topology. I have made these labs with one of my friend when training for the CCIE R&S troubleshooting section. Each lab has 9 tickets and is a bit harder than the real lab exam.

As the topology is based on GNS3 with around 30 routers you will need a powerful machine to run GNS3 on it. An alternative will be to use Amazon Web services and build your own online server in order to run GNS3 on it.  We have used a High-Memory Quadruple Extra Large Instance which is maybe a bit overkilled but it was working really well.

Stay tuned.

Thanks for reading,

Laurent

MPLS Layer 3 VPNs Troubleshooting

I would like to dedicate this post to MPLS L3 VPNs troubleshooting and more particularly using the Traceroute command. It can be sometimes difficult to find out where is the issue when testing connectivity between sites attaches to a MPLS VPN backbone. I will explain the behavior of Traceroute in MPLS VPN environment which is quite different than in “classical” IP environment. Finally I will talk about the MPLS LSP Ping feature and how to use it to detect break in MPLS LSP.

Topology:

 

I am using almost the same topology as the one used in this post: Basic MPLS. I have just added a P router.

 Platform/IOS:

 Cisco 2691/12.4(15)T11 Adv IP services

 First of all if you want to get a basic understanding of MPLS and MPLS Layer 3 VPNs I suggest to read my previous posts: Basic MPLS and MPLS Layer 3 VPNs

 The following is already configured:

• MP-iBGP between R2 and R5
• EBGP between R2 and R1, R5 and R6
• OSPF area 0 between R2,R3,R4,R5
• LDP between R2,R3,R4,R5
• R3 and R4 are P routers and R2 and R5 are PE routers
• R1 is representing the CE device at Site A announcing its loopback address 1.1.1.1/32
• R2 is representing the CE device at Site B announcing its loopback address 6.6.6.6/32

 In this troubleshooting scenario we want to focus on the loopbacks reachability between Site A and Site B.