NAT IP POOL!

[Blizzards <blizzards@libero.it>]

Hi list!


Those are my questions:

A)I need to SNAT a subnet 192.168.1.0/24 with 172.16.1.0/24.
I use this tule:
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to 172.16.1.0/24
This is ok, but when i nat an address, i must create an ip alias on ethn 
an my nat box for this to work. Ok.
When i use few address no problem at all, but using a pool of address (a 
subnet or an interval of ip address), i must create 254 aliases for the 
interface or there was a better method?
B)Iptables Nat a pool of address with 1:1 method like cisco nat?
If yes, when no more address 1:1 are avaiable for connections, can i
se a PAT address like cisco nat?
Or iptables works differently balancing the load of ip address used?

Thanks in advance
Giulius.