routing for dual ifaces and IPs on same NIC

I am using RHEL WS. Can anyone tell me how to setup routing and dual ifaces on same NIC? I have an app with a db that looks for other related servers and infrastructure components via hardwired IPs in the app and database. The app and db must use iface eth0. My difficulty is that I must use an assigned IP from a completely different subnet and mask to network the host.

I want to configure the app and db to see eth0 as the primary iface and then route all external IP traffic via an alias IP and interface eth0:0 on the same NIC. How do I route all external traffic to have source address from eth0:0 via the 10.1.1.1 gateway? Assume i have:

eth0 as.. (app and db must use this as primary)
IP ADDRESS=192.168.1.21
NETMASK=255.255.255.0

and

eth0:0 as (I must use this for all external traffic)
IP ADDRESS=10.1.1.21
NETMASK=255.255.255.0
GATEWAY=10.1.1.1

Also need to use a multi-cast group address of 255.0.0.22

aea

If I understand you correctly you want to set up eth0 for your app but have eth0:0 for normal internet traffic.

From "man route":

Quote:

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dev If force the route to be associated with the specified device

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When you are adding the route for the default gateway use the dev parameter as the last option.

Code:

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route add default gw 10.1.1.1 dev eth0:0

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Change the gateway IP to whatever it should be and you should be set.

Let us know how you get on,

Chris...