To quote mighty Wikipedia: “IP aliasing is associating more than one IP address to a network interface. With this, one node on a network can have multiple connections to a network, each serving a different purpose”
To perform IP aliasing in Debian based system (assuming you’re using eth0), edit /etc/network/interfaces as follows:
auto eth0:1 iface eth0:1 inet static address 10.0.0.10 netmask 255.255.255.0 network 10.0.0.0 broadcast 10.0.0.255 gateway 10.0.0.1 auto eth0:2 iface eth0:2 inet static address 10.0.0.11 netmask 255.255.255.0 network 10.0.0.0 broadcast 10.0.0.255 gateway 10.0.0.1
In the above example we create two virtual NICs out of eth0: eth0:1 10.0.0.10) and eth0:2 (10.0.0.11).
CentOS, RHEL, Fedora and similar
In CentOS, rename /etc/sysconfig/network-scripts/ifcfg-enp0s3 as ifcfg-enp0s3:1 and make a copy as ifcfg-enp0s3:2, and then just change the following lines, respectively:
Once done, restart the network service:
systemctl restart networking