[XCSSA] Re: [SATLUG] Multicast routes

[xcssa@xcssa.org]

On 6/28/06, Jeremy Mann <jeremymann@gmail.com> wrote:
> I can only route the Multicast traffic if I assign the NIC and IP. I
> thought you didn't need an IP address assigned to the outside NIC
> because all its handling is Multicast traffic.

It looks like what you are doing is setting a route for packets
destined TO the multicast IP addresses.  In that case, you need an IP
so the kernel knows what to put in the source IP field.  In any case,
the kernel may require you to have an IP in order to send, even if
it's coming from the multicast IP (although I though multicast IPs
were for destination IPs only, and that replies came as unicast).

> The second problem is after running the iptables script is that for
> some reason the computer wants to route DNS lookups to eth1 instead of
> eth0. I did not set a gateway route for eth1, only an IP address, so I
> don't understand why it insists on using eth1 for DNS lookups.

Is it your default route?  Can you post your routing table and
"ifconfig -a" output?

The key to it all is in the routing table.  That and that alone
decides what interface a packet takes on its journey outbound
(although you can do games with what it sees via iptables rules in the
PREROUTING chain).
-- 
``I put my heart and my soul into my work, and have lost my mind in
the process.''  -- van Gogh - http://www.lightconsulting.com/~travis/
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