reply to unwired
Re: [Tech Ops] MPLS
said by unwired:What sort of routers are you using? With a software based router (i.e. no hardware forwarding), routing table size should be limited only by how much RAM the box has.
The one issue with this config is going to be the routing table size but I feel I'm a few thousand subscribers away from that being a problem.
If its a hardware based router, chances are it will support perhaps hundreds of thousands of FIB entries anyway.
There is also a RIB which is stored in RAM, and is used to populate the FIB. The RIB is usually much bigger than the FIB, since the RIB contains all copies of routes received, while the FIB contains only the ones needed to forward packets.
FIB = Forwarding Information Base
RIB = Routing Information Base
As a side note, the current Internet routing table at I think somewhere around 440,000 routes only consumes maybe 50MB of RAM on a Cisco router.
I have mostly RB50g or 493ah at each pop - Imagestream at the core. I believe at most I have seen my routers spike at 15% cpu and that is with Butch's QOS script running. I will have to relocate Butch's scripts moving forward but was struggling to see just where the benefit in mpls would come vs what I already have in place.