Howto add IP aliases on ppp0 in IPfire

Firewall
Page content

Let’s say you have a /29 network on your DSL subscriber (dial) line: 212.218.10.64/29.

In that case you could use six ip adresses (65 to 70) as public addresses for machines or services behind your firewall.

According to this thread and this thread it is not possible. But it is possible - and i will show you how.

1.) Enable SSH access in ipfire and connect to ipfire as root.

2.) Add the following lines to the file /var/ipfire/ethernet/aliases:

  212.218.10.65,on,RED2
  212.218.10.66,on,RED3
  212.218.10.67,on,RED4
  212.218.10.68,on,RED5
  212.218.10.69,on,RED6
  212.218.10.70,on,RED7

3.) Create a new file (this will configure your ip addresses)

/etc/rc.d/init.d/networking/red.up/02-aliases:

  ip addr add 212.218.10.65/29 dev ppp0
  ip addr add 212.218.10.66/29 dev ppp0
  ip addr add 212.218.10.67/29 dev ppp0
  ip addr add 212.218.10.68/29 dev ppp0
  ip addr add 212.218.10.69/29 dev ppp0
  ip addr add 212.218.10.70/29 dev ppp0
  ip addr show ppp0

4.) Make it executable!

  chmod 0755 /etc/rc.d/init.d/networking/red.up/02-aliases

5.) Restart your Internet connection

READY.

  • The new ip addresses will be automatically configured every time the firewall reconnects or reboots.
  • You will see the addresses in the ipfire menu -> network -> aliases
  • You can use the new addresses in the firewall config - they will appear as RED2 - RED7
  • The warning “Aliases will not be active unless your RED interface is STATIC” can be safely ignored from now on

Have fun ;-)