comcast and verizon

[dsr-mzpnVDyJpH4k7aNtvndDlA at public.gmane.org (Dan Ritter)]

On Wed, Mar 10, 2010 at 06:41:53PM -0500, Stephen Adler wrote:
> Guys,
> 
> I'm planning on switching over to verizon fios, but before I do, I want 
> to test the two out. As it stands now, I have both comcast and verizon 
> fios in my house.
> 
> What I would like to do is setup my servers such that each can talk to 
> either the comcast or verizon network cards. Here's what I have
> 
> eth0 - comcast
> eth1 - verizon
> 
> Now the problem I'm having is that if I set the default router to be the 
> one which goes through the comcast network, then I can only ssh into my 
> system from the comcast ip address. When I try and ssh to the verizon ip 
> address for eth1, it does not connect. Likewise goes for the verizon 
> side. If I set the default route to be through eth1 and the verizon 
> network, then I can ssh to the verizon ip address on eth1 but not the 
> comcast one on eth0.
> 
> What do I have to do to have both up and running? Do I need to setup my 
> server as a router with ip forwarding and all that?

The problem you have is not that packets can't reach your
server; it's that the return packets aren't getting back.

Assuming you're running Linux, here's the HowTo:
http://lartc.org/howto/lartc.rpdb.multiple-links.html

Here's the adventure of someone who has done this:
http://www.miek.nl/s/77951600bc/

-dsr-

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