The other day whilst reading up on some SP topics I came across a rarely used function available on some higher end Cisco models called half duplex VRF’s (or HD VRF’s in some places).
I know it is quite a common thing to see in service provider topologies where you have a radius / virtual-template driven platform such as a DSL LNS etc but up until now I wasn’t aware that it can also be used on other platforms on regular (non virtual) interfaces.
For the demo topology I am going to use a faily simple network of three 7200′s in GNS3. According to the Cisco documentation here this feature has been around since 12.4(20)T or 12.2(33)SRC for the SR train.
In the topolgy I am using R1 and R2 to emulate customer sites which will be a member of the same VRF on R3 which will play the role of our PE.
It has been some time since I last updated the blog but that isn’t to say that I haven’t been working/studying away. After finishing Internet Routing Architectures by Sam Halabi which alongside what I have learned both during my CCNP studies and whilst at my day-to-day job was going to serve as my reading to then go ahead and do the CCIP BGP exam. Before taking the BGP exam I started reading MPLS Fundamentals by Luc D Ghein and then decided that I felt that I would be comfortable enough…