Linux IP Alias

1. Abount IP Alias

IP alias/ip aliasing is assigning multiple IP addresses to a single physical network interface. Alias network interface is configured on top of existing physical network interface.

By IP aliasing we can make applications and services running on Linux server available on multiple IP addresses by using O nly one physical network interfase.

Requirements for IP alias

* Physical Network Interface Connectivity

* Available multiple IP Addresses

Limitations of IP alias:

* Subnet aliasing (alias network interface IP address is preffered to BES in the same network Subnet a s physical network interface below–if not proper network infrastructure configuration is needed)

* DHCP (alias interfaces don't support DHCP)

Example:nic eth0 192.168.1.100

2. Non-persistent IP Alias Configuration

[Email protected] ~]$ ifconfig eth0:0 192.168.1.100 up

3. Persistent IP Alias Configuration

[Email protected] network-scripts]$ Cat/etc/sysconfig/network-scripts/ifcfg-eth0

Device=eth0

Type=ethernet

Onboot=yes

Nm_controlled=no

Bootproto=none

ipaddr=192.168.1.100

Prefix=24

gateway=192.168.1.1

dns1=114.114.114.114

Ipv4_failure_fatal=yes

Ipv6init=no

Name= "System eth0"

[Email protected] network-scripts]$ cat/etc/sysconfig/network-scripts/ifcfg-eth0\:0

Device=eth0

Type=ethernet

Onboot=yes

Nm_controlled=no

Bootproto=static

Onparent=yes

Ipaddr=192.168.1.101

Prefix=24

Ipv4_failure_fatal=yes

Ipv6init=no

Name= "System eth0:0"

Linux IP Alias