How to add an additional IP address to a network card in FreeBSD

Note the word alias on the end of the command. If it’s not there, this command will replace the current IP address with the one that we intend to add. In this tutorial as network adapter I use dc0 (# DEC/Intel 21143 and various workalikes). You will need to use whatever suits your needs.

$ ifconfig dc0 inet 192.168.0.100 netmask 255.255.255.255 alias

To have this IP alias loaded after reboot, edit and add the following line to /etc/rc.conf file:

ifconfig_dc0_alias0="inet 192.168.0.100 netmask 255.255.255.255"

The subnet mask is correct when the new IP address is on the same subnet as the primary IP address. Only one IP per subnet on an adapter should have a real subnet mask other than 255.255.255.255. 

Removing an IP alias from a network card in FreeBSD

$ ifconfig dc0 inet 192.168.0.100 -alias

Now use ifconfig dc0 command to see the results.

Bookmarks:

Echo "FreeBSD: Add/remove an additional IP alias " around:

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