Setting up IP Aliasing on A Linux Machine
Overview
IP Aliasing is built into the Linux 2.4.x kernel.
Configuration
- Log on as user "root".
- Configure the aliased network device/
/sbin/ifconfig eth0:0 10.0.1.171 up
/sbin/ifconfig eth0:1 10.0.1.172 up- To re-establish the new IP address after a boot, put the above lines in /etc/rc.local
- Insert a line in /etc/hosts identifying new address. For example:
10.0.1.171 machine1 machine1.mn.acme.com machine1.acme.com- Setup the routes. First route the loopback, then the net, and finally, the various IP addresses starting with the default (originally allocated) one:
/sbin/route add -net 127.0.0.0
/sbin/route add -net 10.0.1.0 dev eth0
/sbin/route add -host 10.0.1.170 dev eth0
/sbin/route add -host 10.0.1.171 dev eth0:0
/sbin/route add -host 10.0.1.172 dev eth0:1
/sbin/route add default gw 10.0.1.1- To verify results, run ifconfig
If you ever get locked out of the machine because of the aliased network device, you can run:
rm -f /etc/sysconfig/network-scripts/ifcfg-eth0:0
service network restart
Keeping settings through a reboot
To keep the IP alias settings through a reboot, config it in /etc/rc.d/rc.local.#setting up IP alias interfaces
/sbin/ifconfig eth0:0 10.0.1.171
/sbin/ifconfig eth0:1 10.0.1.172
echo "Setting IP alias routes ..."
/sbin/route add -host 10.0.1.171 eth0:0
/sbin/route add -host 10.0.1.172 eth0:1