Re: Multiple ISP connection

[mikepolniak <mikpolniak@adelphia.net>]

On 18:39 Fri 11 Nov     , choy wrote:
> Hi,
> 
> I have a web server connected indirectly to the Internet(ISP -> router
> -> server eth0). I've setup NAT port forward in the router so all web
> server connections are forwarded to server. Recently, I've added a new
> ethernet card(eth1) to the server, and it has a public ip(ISP ->
> server eth1). After ifup'ing eth1, I can't connect to my server from
> old IP(eth0) anymore, but from new ip is OK. If I ifdown eth1, eth0
> work as before.
> 
> So my question is: how can I config the server so both connection
> (eth0 and eth1) can connect to my server?
> 
One way to do this is with iproute. Read "Linux Advanced Routing & Traffic
Control HOWTO" sec 4.2  "Routing for multiple uplinks/providers";  
in which there are two providers that connect a local network (or even a 
single machine) to the big Internet.

http://lartc.org/howto/lartc.rpdb.multiple-links.html#AEN268

You will need to install "iproute" and set up routing tables in 
/etc/iproute2/rt_tables  something like this example, etc.

	  ip route add $P1_NET dev $IF1 src $IP1 table T1
	  ip route add default via $P1 table T1
	  ip route add $P2_NET dev $IF2 src $IP2 table T2
	  ip route add default via $P2 table T2