/etc/network/interfaces: What's <eth>:<num> mean? [closed]

Question

In /etc/network/interfaces, I have a physical eth0 and a vlan eth0.10, however there is an additional eth0:0

iface eth0 inet manual

iface eth0.10 inet manual
    vlan-raw-device eth0

iface eth0:0 inet manual

What does a colon mean in interfaces file? Is it the same as a dot?

Answer 1

Column in network interfaces mean virtual interface. Here is in Debian/Ubuntu:

[root@ubuntu ~]# cat /etc/network/interfaces
iface eth0:0 inet static
address 123.123.22.22
netmask 255.0.0.0
broadcast 123.255.255.255

For more info you can check here.

As far as I remember you can have up to 255 (or 256, not sure) virtual interfaces per physical one.