using sub-interface to separate LAN

[Ron <nhadie@gmail.com>]

Hi All,


Would it be a good idea to separate 4 different groups connected to the 
same switch using just sub-interface, VLAN should be the way, but not 
sure if VLAN will work as i only have layer 2 switches.

So what i'm planning is just use my debian box as a NAT gateway.

setup this way:

eth1 192.168.1.0/24
eth1:0 192.168.2.0/24
eth1:1 192.168.3.0/24
eth1:2 192.168.4.0/24

and then changed the IP address on the machine to belong on which 
subnet. what problems may i encounter on this kind of setup?

Thanks in advanced.

Regards
Ron