[Xorp-users] Unreachable default route.

[Pavlin Radoslavov]

Tim Durack <tdurack at gmail.com> wrote:

> On a Cisco you would configure a floating static route - that is a
> static with a higher administrative distance than a dynamic routing
> protocol. The static will be overridden by the dynamic, but if the
> dynamic default goes away, the static will be installed.
> 
> Not sure if XORP supports this (I don't think you can change admin
> distance), so this probably doesn't help.

No, unfortunately XORP doesn't support floating static routes (yet).
The RIB itself has already XRL interface to set the admin distance
per protocol, but this interface is not used yet, and it will set
the admin distance for all routes for a given protocol.

If modifying the admin distance for all static routes (so they are
less preferred than, say, OSPF) is acceptable to you, the easiest
hack is to modify rib/rib.cc (the RIB constructor) and change the
"static" entry for _admin_distances to a value that is larger than
the dynamic protocols (e.g., 220).

Regards,
Pavlin

> Tim:>
> 
> On 8/30/07, Ben Greear <greearb at candelatech.com> wrote:
> > Pavlin Radoslavov wrote:
> > > Ben Greear <greearb at candelatech.com> wrote:
> > >
> > >
> > >> Is there a way to get Xorp to put in an un-reachable default route
> > >> if no default gateway is known/configured for a particular routing table?
> > >> This keeps Linux from trying other routing tables (for instance, when you
> > >> have specified a particular routing table per some rule.)
> > >>
> > >>  From the command line, you'd do something like:
> > >>
> > >> # 100 is the routing table ID
> > >> ip route add unreachable 0/0 table 100
> > >>
> > >
> > > It sounds like you need to configure a discard interface, and point
> > > the default route to that interface.
> > >
> > I only want this to exist _IF_ there is no valid default route.  So, I
> > think it would have to
> > be more dynamic than a config file, since I assume OSPF or similar might
> > negotiate a
> > default route (and fail to find one at other times??)
> >
> > Ben
> >
> > --
> > Ben Greear <greearb at candelatech.com>
> > Candela Technologies Inc  http://www.candelatech.com
> >
> >
> > _______________________________________________
> > Xorp-users mailing list
> > Xorp-users at xorp.org
> > http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users
> >
> 
> _______________________________________________
> Xorp-users mailing list
> Xorp-users at xorp.org
> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users