one computer two ip address

[HillarP]

Marius Gedminas wrote:

> I have to admit that I never understood the point of the alias
> interfaces.  I always did
> 
> auto eth0
>         iface eth0 inet static
>         address 192.168.0.10
>         netmask 255.255.255.0
>         gateway 192.168.0.1
>         up ip addr add 192.168.0.11/24 dev eth0
>         up ip addr add 192.168.0.12/24 dev eth0
> 
> and it worked fine.

It's not a good idea. Most of applications send their request to IP address.
If there is only one device, it must deal with all those requests and
figure out an application to whom those must forwarded. Also application
sends answer and there isn't determined which IP address the answer gets.
If you have different interfaces, you can determine what interface (and IP
address) are used. Also can you set up virtually separated networks.

-- 
With best regards
HillarP