Hope someone can help, I've tried this on a Fedora, Centos and now on Ubuntu machine.

I need to configure one interface on 10.0.10 and one on 171.31.4. to receive a multicast stream from the VPN, but when I attempt configuring both with gateways I can't get traffic over both networks.

I have attempted both interfaces static, as well as attempting static and dhcp. I have this working on a Mac OS X server, so I know that all the networking for both LANs are fine.

In Mac OS X this seems to work just fine having two default gateways.

On Ubuntu - latest test - two default gateways and still no traffic over the 171 network.

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
171.31.4.0 * 255.255.255.0 U 0 0 0 eth1
10.0.10.0 * 255.255.255.0 U 0 0 0 eth0
default 171.31.4.1 0.0.0.0 UG 100 0 0 eth1
default 10.0.10.1 0.0.0.0 UG 100 0 0 eth0

Fedora 12:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.31.4.0 * 255.255.255.0 U 1 0 0 eth1
10.0.10.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 1002 0 0 eth0
default 10.0.10.1 0.0.0.0 UG 0 0 0 eth0

When I do
route add default gw 172.31.4.1
I can get multicast but I lose the connection to the external network.

Any ideas for how to proceed in this would be appreciated!!

http://kindlund.wordpress.com/2007/1...utes-in-linux/

See note about kernel.

http://eglug.org/node/2188

First flushed the routing table to get rid of all the previous junk - devils in the details. Solved this by creating ip tables for the two different IP access points, and did install iproute2.

Basically this is what I did, where OTHER is the 2nd internet connection
and COMCAST has internal IP, but provides the main connection out:

echo 1 COMCAST >> /etc/iproute2/rt_tables
echo 2 OTHER >> /etc/iproute2/rt_tables

ip route add default via 10.0.10.1 dev eth0 table COMCAST
ip rule add from 10.0.10.0/24 table COMCAST

ip route add default via x.x.x.1 dev eth1 table OTHER
ip rule add from x.x.x.0/24 table OTHER

ip rule add to x.x.x.0/24 table OTHER
ip rule add to 10.0.10.0/24 table COMCAST

ip route add default nexthop via 10.0.10.1 dev eth0 nexthop via x.x.x.1 dev eth1

Again, thanks for pointing me in the right direction!