Re: multiple external IP's - virtual NIC - DNAT problems

[Sven-Haegar Koch <haegar@sdinet.de>]

On Fri, 29 Jan 2010, koen.news@koca.be wrote:

> > The command you seek is "ip".  Here's an example of adding an address to
> > an interface:  "ip address add 1.2.3.4/8 dev eth4".
> >
> > Happy hacking!
> > Mike Wright
> >
> Thx for the reply. That's indeed what I seek!
> 
> I guess I can put that command (or the debian variant) in the pre-up
> command for the interface?

Not pre-up, put them in up / post-up

You can also use eth0:1 eth0:2 interface definitions in debian 
/etc/network/interfaces and use "-i eth0 -d $ip" in your firewall 
config.

The eth0:X interfaces are not really network interfaces, they are just 
secondary ip addresses on the base interface with a different label 
attached to them for ifconfig backward compatibility.

Example:
	ifconfig eth2:2 192.168.19.123 up
	ip addr show dev eth2
	-> inet 192.168.19.123/24 brd 192.168.19.255 scope global secondary eth2:2

	ip addr add 192.168.19.124/24 dev eth2
	ip addr show dev eth2
	-> inet 192.168.19.123/24 brd 192.168.19.255 scope global secondary eth2:2
	-> inet 192.168.19.124/24 scope global secondary eth2


c'ya
sven

-- 
Three may keep a secret, if two of them are dead.
- Ben F.