routing question (almost there!)

[Paul Howarth]

On Tue, 2005-02-08 at 16:21 -0500, Douglas Frank wrote:
> Oops yes it is.  Anyway I'm past that (see earlier post)-- the box I 
> *thought* was the router, isn't.
> 
> I'm almost all set-- I just need to know how to make the routing table 
> permanent.  Looking at /etc/rc.d/rc5.d/S10network, it reads a static-
> routes file (if present) and adds routes found there.  Looks like all
> I have to do is gin up a file for it to read.  Unfortunately the rc 
> script dosn't allow the arguments I think I need:
> 
> the rc script invokes route sort of like this:
> 
>    cat static_routes | while read ignore args ; do
> 	/sbin/route add -$args
>    done

Rumour has it that the static-routes file is deprecated (at least that's
what it says at http://www.linuxhomenetworking.com/linux-hn/appendix-
diff.htm and http://www.linuxhomenetworking.com/linux-hn/dchp.htm and
also mentioned at https://bugzilla.redhat.com/bugzilla/show_bug.cgi?
id=108696).

> The lines I *want* to generate to route are:
> 
>    route add -net <router's_network> netmask 255.255.255.0 eth0
>    route add default gw <router_1>
>    route add default gw <router_2>
> 
> but the darn '-' in the script gets in the way of the 2nd & 3rd lines, 
> route(8) doesn't like "-default".  (The local network router doesn't 
> have an address on the local net.  Beats me!  The switches around here
> are a madhouse.)
> 
> What's the trick? (Yes I could edit the rc script but would rather not).

Hmm, multiple default routes, that's unusual. Are you sure that's what
you really want and not:

default route via router0
route to otherlan1/prefix1 via router1
route to otherlan2/prefix2 via router2

You'd set this up as follows:

1. Add a line:

   GATEWAY=router0-IP

   to /etc/sysconfig/network

2. Add lines:

   otherlan1/prefix1 via router1-IP
   otherlan2/prefix2 via router2-IP

   e.g.

   16.47.32.0/24  via 16.140.160.1
   16.32.176.0/24 via 16.140.160.2

   to /etc/sysconfig/network-scripts/route-eth0

If you really do need multiple default routes, a non-Fedora-specific
guide to handling routing for multiple uplinks/providers can be found
at: http://lartc.org/howto/lartc.rpdb.multiple-links.html

Paul.
-- 
Paul Howarth <paul at city-fan.org>