There are cases where you need more than one IP on a server. How do you assign a second IP to a Network Interface Card?
In Redhat-based distributions there is a directory, /etc/sysconfig/network-scripts/, that contains configuration files for each network device (such as ifcfg-eth0 for the first ethernet card.)
The easy way to assign a second IP to one of these cards is to make a copy of the file, alias the device name and change the IP. For example: Let's say that eth0 is configured for the IP 192.168.1.1 and you also want it to listen to IP 192.168.1.2. Here's what you do:
First, cd to the network-scripts directory:
# cd /etc/sysconfig/network-scripts/
Next, make a copy of the configuration file:
# cp ifcfg-eth0 ifcfg-eth0-2
Now edit the file. There are only two lines that you really need to change:
- You need to update the device= line to give an alias name to the device and
- You need to change the IP= line to reflect the desired IP.
In this case, the original lines would be:
You want to edit them to read:
That's all! Save your changes and restart your network:
# service network restart
Now, when you check your network configuration you will find an extra device with the new IP: