[j-nsp] load balancing in Route reflector scenario

[Robert Raszuk]

Hi Keegan,

> I think the advertise inactive knob turns that off, but I don't know for
> sure because I've never tried it.  I know it's not supported on cisco
> routers.  The reason for it is the size of the BGP table.  So if the table
> is 400k routes and you have 5 different ISP's and you advertise every route
> that would be 2M routes in the table.  Since BGP doesn't allow multiple
> version of the same route in the routing table (separate from the BGP table
> where incoming routes are stored) you would still only use the original 400K
> the other 1.8M routes would just go unused unless you manipulated them some
> how.

Advertise inactive is not about what get's advertised - it is about if 
the best path is advertised or not. And if is decided based on the check 
if the BGP path to be advertised is inserted in the RIB/FIB or not.

By default Junos and IOS-XR advertise only those best path in BGP which 
actually are installed into forwarding. Advertising inactive knob will 
overwrite it.

IOS classic/XE (for historical reasons) advertises all best paths from 
BGP table and to enforce it not to advertise what has not been installed 
into RIB/FIB there is knob called "suppress inactive".

Cheers,
R.