Very Computer

We have a linux box with kernel 2.2.xx (SuSE 6.4)
three networks attached:
- one with 4 public static ip addresses
- one with a private ip address
- one with another private ip address in a diffrent subnet
masquerading done with ipchains

Is it possible to do an masquerading for computers in private network 1 with
public ip adress 1 and for computers in private network 2 with public ip
adress 2?

If it is not possible with kernel 2.2.xx, is it possible with kernel 2.4.X?

Martin

Quote:> Is it possible to do an masquerading for computers in private network 1
> with public ip adress 1 and for computers in private network 2 with public
> ip adress 2?

> If it is not possible with kernel 2.2.xx, is it possible with kernel
> 2.4.X?

To achieve what you want you would need to make the linux machine accept
packets to the two public IP addresses on one interface - the most obvious
way I can think of to achieve this would be IP aliasing (you'd end up with
eth0:0 and eth0:1 or something)

Having accomplished this you would do the following commands, assuming that

public interface on eth0:0 = 1.1.1.1
public interface on eth0:1 = 1.1.1.2
private net 1 = 192.168.0.0/24
private net 2 = 192.168.1.0/24

iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -d ! 192.168.0.0/16 \
-j SNAT --to-source 1.1.1.1

AND

iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -d ! 192.168.0.0/16 \
-j SNAT --to-source 1.1.1.2

these rules basically match everything that is from a private network that
isn't going to the other private network, and changes the source ip to the
appropriate one (de-masquerading is handled automatically)

N.B. these rules could probably be "hardened" for security - but the basic
idea is there

Good luck,
Julian

Quote:> To achieve what you want you would need to make the linux machine accept
> packets to the two public IP addresses on one interface - the most obvious
> way I can think of to achieve this would be IP aliasing (you'd end up with
> eth0:0 and eth0:1 or something)