[LARTC] load balance/redundancy

[Arthur van Leeuwen arthurvl@sci.kun.nl]

<PRE>On Sun, 10 Dec 2000, Paul wrote:

&gt;<i> Arthur,
</I>&gt;<i> 
</I>&gt;<i> Thanks for your help.  I tried what you suggested, here is the result:
</I>&gt;<i> 
</I>&gt;<i> # /sbin/ip route add default nexthop via 24.141.xxx.1 nexthop via
</I>&gt;<i> 64.229.xxx.1
</I>&gt;<i> RTNETLINK answers: Network is unreachable
</I>
You forgot to setup host routes to 64.229.xxx.1 and 24.141.xxx.1 over the 
correct interfaces.

&gt;<i> So instead, I tried:
</I>&gt;<i> 
</I>&gt;<i> # /sbin/ip route add default nexthop via 24.141.xxx.1 dev eth0 nexthop via
</I>&gt;<i> 64.229.xxx.1 dev ppp0
</I>
Well, that works as well. No host routes needed. :)

&gt;<i> # ip route ls
</I>&gt;<i> 64.229.xxx.1 dev ppp0  proto kernel  scope link  src 64.229.xxx.12
</I>&gt;<i> 24.141.xxx.0/22 dev eth0  proto kernel  scope link  src 24.141.xxx.89
</I>&gt;<i> 127.0.0.0/8 dev lo  scope link
</I>&gt;<i> default
</I>&gt;<i>         nexthop dev eth0 weight 1
</I>&gt;<i>         nexthop dev ppp0 weight 1
</I>
Ah, yes. You might get problems with the selection of the source address you
come from though. The situation that might occur is a route going over ppp0
using 24.141.xxx.89 as source address. That will probably *not* work.

&gt;<i> Now this seems to work.  Is there anything wrong with this?  Can you take
</I>&gt;<i> a guess at why what you suggested didn't work?  I think I tried all the
</I>&gt;<i> different permutations with addresses, I think the problem must come from
</I>&gt;<i> the pppoe interface.
</I>
I don't think the problem comes from the pppoe interface. I've set up stuff
like this with ppp over pptp over ethernet links (*silly* ADSL setup), and
that works as well.

&gt;<i> Now all I have to do is kludge something together for my redundancy, set
</I>&gt;<i> up firewalling, and masqerading.
</I>
Note: you may want to set up policy rules for dealing with packets that
already have a source or destination address. This will let servers running
on your system that bind to 0.0.0.0/0 answer to requests from both links
over the correct link. Browse through the mailinglist archives for some
hints on how to set that up.

Doei, Arthur.

-- 
  /\    / |      <A HREF="mailto:arthurvl@sci.kun.nl">arthurvl@sci.kun.nl</A>      | Work like you don't need the money
 /__\  /  | A friend is someone with whom | Love like you have never been hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody watching



</PRE>