[j-nsp] improving global unicast convergence (with or without BGP-PIC)

[Alexander Arseniev]

Hi Dragan,


> As for default route, if its installed in FT, I don't see why the 
> router wouldn't use this entry in the absence of more specific 
> (bearing all other issues with such setup).
>
Yes, the 0/0 will be used BUT when there are 100,000s of more specifics 
in the FIB BEING REMOVED (simplest case, when eBGP+iBGP both supply just 
one 0/0 route each) there will be period of time when stale specific 
routes are stil used for forwarding -> packet loss persists for this 
period of time.
BTW, You should deny BGP NH resolution via this 0/0, or the packet loss 
is unnecessarily prolonged.
The FIB update happens with finite speed, be it route addition, route 
removal or route nexthop rewrite.
NH rewrite is sped up with INH.
The performance of the other operations is improved in recent JUNOS 
(16.1+ if memory serves, ask Juniper account team for details).
HTH
Thx
Alex