[j-nsp] no inet.2 for multicast RPF etc. by default?

[Pekka Savola]

On Tue, 15 Apr 2003, Leonard Giuliano wrote:
> Yes, inet.0 is used by default.  If you want pim and/or msdp to use
> inet.2, you just need to configure these protocols to do so.
> 
> protocols {
>     msdp {
>         rib-group inet pim-rg;
>     }
>     pim {
>         rib-group inet pim-rg;
>     }
> }

But there is *no* way to try inet.2 first, and if it fails, only then go 
back to inet.0 ?

This would really, *really* simplify things in scenarios when most routes 
are unicast-multicast congruent, but some of them are not.

Otherwise you have to copy all the routes in inet.0 to inet.2 and even 
then you get breakage if you have multicast routers which do not speak 
MBGP in your network.

> On Tue, 15 Apr 2003, Pekka Savola wrote:
> 
> -) Hi,
> -)
> -) It seems to me that Juniper does not use inet.2 at all by default.
> -)
> -) That is, even if I configure routes for inet.2 or use MBGP to distribute
> -) multicast routes when unicast/multicast topology is not congruent, Juniper
> -) only uses inet.0 by default.
> -)
> -) This seems *odd*.  The desired behaviour should be to always look for
> -) inet.2 first, and if it fails, look at inet.0 (or so I've been believing).
> -) Otherwise, being transit using MBGP (for example) would likely break RPF
> -) quite badly.
> -)
> -) Am I missing something?
> -)
> -) --8<--
> -) Configure PIM RPF Routing Table
> -) By default, PIM uses inet.0 as its Reverse Path Forwarding (RPF) routing
> -) table group. PIM uses an RPF routing table group to resolve its RPF
> -) neighbor for a particular multicast source address and to resolve the RPF
> -) neighbor for the RP address. PIM can optionally use inet.2 as its RPF
> -) routing table group. To do this, add the rib-groups statement at the [edit
> -) routing-options] hierarchy level.
> -)
> -) routing-options {
> -)     rib-groups {
> -)         pim-rg {
> -)             import-rib inet.2;
> -)          }
> -)     }
> -) }
> -) protocols {
> -)     pim {
> -)         rib-group inet pim-rg;
> -) --8<--
> -) blah at foo> show route x.y.0.0
> -)
> -) inet.0: 153 destinations, 215 routes (152 active, 0 holddown, 1 hidden)
> -) + = Active Route, - = Last Active, * = Both
> -)
> -) x.y.0.0/16     *[BGP/170] 16:10:57, MED 0, localpref 200, from 172.31.5.199
> -)                       AS path: 65300 I
> -)                     > to a.b.c.177 via ge-1/0/0.0
> -)
> -) inet.2: 130 destinations, 180 routes (129 active, 0 holddown, 1 hidden)
> -) + = Active Route, - = Last Active, * = Both
> -)
> -) x.y.0.0/16     *[BGP/170] 5d 02:15:43, MED 0, localpref 50, from 172.31.5.198
> -)                       AS path: 65300 I
> -)                     > to a.b.c.1 via fe-0/3/1.0
> -)                       to a.b.c.25 via fe-0/3/3.0
> -)
> -) blah at foo> show multicast rpf x.y.0.0
> -) Multicast RPF table: inet.0, 153 entries
> -)
> -) x.y.0.0/16
> -)     Protocol: BGP
> -)     Interface: ge-1/0/0.0
> -) --8<--
> -)
> -) --
> -) Pekka Savola                 "You each name yourselves king, yet the
> -) Netcore Oy                    kingdom bleeds."
> -) Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
> -)
> -) _______________________________________________
> -) juniper-nsp mailing list juniper-nsp at puck.nether.net
> -) http://puck.nether.net/mailman/listinfo/juniper-nsp
> -)
> 

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings