multi-honed Plesk, two eth cards

[hackhawk]

Hello,

I was unable to find any information in the forums on this topic, so I thought I'd post what I'm doing.

Basically I'm migrating a Plesk server from one physical sub-net to another on a completely different switch and sub-net. The switches are physically close enough that I can use both Eth cards on the Plesk server to allow access to both subnets at the same time. The reason for this is to limit downtime during the migration as some visitors may have the old (DNS) address cached.

There are two obstacles to overcome.

1) Setting up Linux to be Multihoned
2) Setting up Plesk to use both IP's

I'm not entirely finished trying #2 yet, but it seems to be working.

--- Here's what I've done -----

1) Setup Linux to be Mulit-honed

a) edit /etc/sysconfig/network-scripts/
       ifcfg-eth0 & ifcfg-eth1
       Assuming you're migrating to the
       subnet on eth1, eth1 will be your
       primary outbound interface.

b) add the following two lines to
      /etc/iproute2/rt_tables

      200     T1
      201     T2

c) setup the following file to run at startup.
       ensure UPPERCASE variables are
       replaced by the correct information.
       /etc/rc.d/init.d/iproute

       #!/bin/sh
       ip route add NEW_IP_NET dev eth1 src NEW_IP_ADDR table T1
       ip route add default via NEW_IP_GATEWAY table T1
       ip route add OLD_IP_NET dev eth0 src OLD_IP_ADDR table T2
       ip route add default via OLD_IP_GATEWAY table T2
       ip route add NEW_IP_NET dev eth1 src NEW_IP_ADDR
       ip route add OLD_IP_NET dev eth0 src OLD_IP_ADDR
       ip route del default via OLD_IP_GATEWAY
       ip route add default via NEW_IP_GATEWAY
       ip rule add from NEW_IP_ADDR table T1
       ip rule add from OLD_IP_ADDR table T2

d) Run (service network restart)

e) Run (/etc/rc.d/init.d/iproute)

2) Setting up Plesk to use both IP's

I couldn't locate anywhere within plesk to change the IP address of the Virtual/Shared Hosts to use the new IP/Interface. Someone please correct me if there is a way to do this.

a) You need to edit the files located at...

       /var/www/vhosts/SITENAME/conf/httpd.include

Duplicate all of the references in the 
VirtualHost area and reference the new IP 
Address for the duplicated section.

b) Run (service restart httpd)

Hope this helps if anyone is looking to do the same thing. And if I've done something that's incompatible with Plesk, please speak up.