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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

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?

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You know NetworkManager was designed to do the job you need? Why isn't it, or why don't you want it installed? – Tim Jun 5 '12 at 14:39
I have a CentOS server basic installation. I'm not very experimented with Linux, but I think, for what I need, NetworkManager is useless. – artaxerxe Jun 5 '12 at 17:22
up vote 1 down vote accepted

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.

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