[j-nsp] load balancing in Route reflector scenario

[Robert Raszuk]

Hi Keegan,

> I thought advertise inactive just configured the routers to advertise the
> entire BGP RIB instead of only advertising the routes in the routing-table.

Nope. BGP advertises by default single best path. Any subsequent 
advertisement will be an implicit withdraw.

Hi Humair,

Per RR different local policy is a valid workaround int he case as 
reported by biwa. But care must be taken that the network either 
supports end to end encapsulation (example: mpls) or that all routers on 
the way will get the same paths.

Hi Biwa,

1. The easiest option is to get rid of RR .. just do full IBGP mesh. I 
know large networks doing it today :)

2. The other option is to put RR in the data path and enable multipath 
in it. The end effect will be the same as enabling it on PE1.

3. To signal both paths to PE1 from RRs you need either add-paths or 
diverse-path. Add-paths will require support on PE1 while diverse-path 
will not. And depending on the choice of RR diverse-path is available 
today in some implementations :-)

4. Another way is to do ghost loopback (aka anycast next hop self) on 
PE2 and PE3 and let the IGP load-balance across both PEs. Works well if 
you have symmetry of IGP and routes of both PE2 and PE3.

Cheers,
R.