Bring up alias interface on boot, when the main interface is down

Question

In my CentOS 6.2 server, I have the following configuration for networking:

• The NetworkManager package wasn't installed
• on eth0 I have a DHCP configuration
• on eth0:1 alias interface I have a static IP, lets say 10.10.10.10

When I have connected my server to internet and boot up, both interfaces are brought up well, but when I don't have a connection to the internet (with other words, when it isn't allocated an IP through DHCP to the main interface) and boot up, the alias interface is also down.

Question: Is there a way to prevent this behavior? Or how to bring up the alias interface when boot up the server, even if the main interface is down?

Answer 1

First line from the networkmanager man page:

The NetworkManager daemon attempts to make networking configuration and operation as painless and automatic as possible by managing the primary network connection and other network interfaces, like Ethernet, WiFi, and Mobile Broadband devices.

Sounds like a good fit to me, but if you still want to do something else, you can find a NM alternative/replacement, or add your specific command to /etc/rc.local.

Commands added to /etc/rc.local are executed immediately after all other service scripts have finished.

/etc/rc.local exists in RHEL, Cent, Fedora and OpenSuse to my knowledge.