Add Virtual IP in Linux

Steps to add virtual IP.

1)Copy existing device etho to new virtual device.
#cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0:1

2)Edit device and IP address in ifcfg-eth0:1
#vi ifcfg-eth0:1

3)Restart the network service
#service network restart

4)Verify the virtual device is up. You'll see 2 different IP address.I've purposely hide the IP address,Bcast and Netmask. You should get the reply once ping.

# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:50:56:BE:00:3B
inet addr:xx.x.xxx.184 Bcast:xx.x.xxx.xxx Mask:xxx.xxx.xxx.x
inet6 addr: fe80::250:56ff:febe:3b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:36 errors:0 dropped:0 overruns:0 frame:0
TX packets:28 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3751 (3.6 KiB) TX bytes:4480 (4.3 KiB)

eth0:1 Link encap:Ethernet HWaddr 00:50:56:BE:00:3B
inet addr:xx.x.xxx.185 Bcast:10.9.135.255 Mask:255.255.248.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
#ping xx.x.xxx.185
PING xx.x.xxx.185 (xx.x.xxx.185) 56(84) bytes of data.
64 bytes from xx.x.xxx.185: icmp_seq=1 ttl=64 time=0.018 ms
64 bytes from xx.x.xxx.185: icmp_seq=2 ttl=64 time=0.018 ms