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

[Leonard Giuliano]

On Tue, 15 Apr 2003, Pekka Savola wrote:

-) 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 ?
-)

I believe you can do this by copying the rest of the inet.0 routes into
inet.2, and somehow give them a lower preference.  I think the behavior
you want is possible, but it may take some configuration.


-) 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
-)