[LARTC] Load Sharing PPP Connections on an Masqed LAN

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

<PRE>On Tue, 5 Dec 2000, Rogerio Brito wrote:

&gt;<i> On Dec 04 2000, Arthur van Leeuwen wrote:
</I>&gt;<i> &gt; Second: set up /etc/ppp/ip-up.local scripts (not exactly sure what Mandrake 
</I>&gt;<i> &gt;         uses for that, but that's what RedHat uses) to dynamically reroute
</I>&gt;<i> &gt;         to the correct interfaces
</I>&gt;<i> 
</I>&gt;<i> 	Could you provide more information on what is meant by
</I>&gt;<i> 	&quot;dynamically reroute&quot;? By that you mean that ppp shouldn't add
</I>&gt;<i> 	default routes to the gateways?
</I>
Oh, no. By that I mean that the ip-up.local script should set the route
itself, depending on whether there are one or two ppp links up already. This
is relatively easy to figure out using 'ip addr' and some awk.

&gt;<i> &gt; Third: make a multipath route over the two ppp links. This will dynamically
</I>&gt;<i> &gt;        balance packets over the two links, based on the destination adresses.
</I>&gt;<i> 
</I>&gt;<i> 	Which way would I do this? Should I delete my default route
</I>&gt;<i> 	and use:
</I>&gt;<i> 
</I>&gt;<i> 	# ip route add default scope global nexthop dev ppp0 nexthop dev eth0
</I>
That is correct.

&gt;<i> 	(so that I can use both my ppp connection and my DSL?)
</I>&gt;<i> 
</I>&gt;<i> 	I tried the above and it &quot;partially&quot; works: I have problems
</I>&gt;<i> 	accessing some www sites (Netscape shows me &quot;No route to
</I>&gt;<i> 	host&quot;), while accessing others is fine (I can read slashdot
</I>&gt;<i> 	ok).
</I>&gt;<i> 
</I>&gt;<i> 	It seems that the problem only occurs with TCP based services
</I>&gt;<i> 	(UDP based ones seem to be fine -- ICMP echo also seems fine).
</I>&gt;<i> 
</I>&gt;<i> 	Any suggestion what I should be doing to correct this?
</I>
You should add gateways for the different outgoing devices and set up host
routes to those gateways specifying as the preferred source address the
address associated with the interface through which you route to the
gateway. Further, adding rulesets to deal with the case that packets already
have a source address set might greatly improve reliability. There's some
information on how to do that in some previous mails I made to the list.

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>