Monday, February 2, 2015

Troubleshooting OSPF - LAB 1

Here is a quick lab I put together to really test your knowledge about OSPF Path selection and some of the hidden rules behind the path selection.

Simple topology below.


Objective: 
  • R3 should choose R2 over Gi1.23 to reach R1 loopback 150.1.1.1/32. Imagine that this is a 40Gbit link where as Gi1.13 is just a 100Mb link. Currently R3 is choosing Gi1.13 to reach R1 loopback 150.1.1.1/32. 
Restrictions:
  • Do not configure any new routing protocols.
  • Do not change Area numbers.
  • Do not create any NEW areas. 
  • Do not change OSPF cost values
  • R3 should choose R1 with OSPF as the routing protocol so no STATIC routes etc. 
Configuration excerpts below so you can configure it in your lab.