Many to many NAT

Many to many NAT

[Robert LeBlanc]

I've looked online and can't seem to find a HOW-TO on this. I've
configured iptables to do a many to many NAT, but traffic is not
accepted because the IP address does not exist on the outside interface.

iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to 1.2.3.0/25

I'm thinking that I need to add a route for this to work, but I'm not
terribly sure. Would something like this work?

route add -net 1.2.3.0/25 gw 192.168.1.1
Or
route add -net 1.2.3.0/25 gw 1.2.2.1
Or
route add -net 1.2.3.0/25 dev eth0
Where eth0 is the external interface.

Thanks,
Robert

Re: Many to many NAT

[Robert LeBlanc]

On 6/16/07 6:28 PM, "Robert LeBlanc" <robert@leblancnet.us> wrote:

> I've looked online and can't seem to find a HOW-TO on this. I've
> configured iptables to do a many to many NAT, but traffic is not
> accepted because the IP address does not exist on the outside interface.
> 
> iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to 1.2.3.0/25
> 
> I'm thinking that I need to add a route for this to work, but I'm not
> terribly sure. Would something like this work?
> 
> route add -net 1.2.3.0/25 gw 192.168.1.1
> Or
> route add -net 1.2.3.0/25 gw 1.2.2.1
> Or
> route add -net 1.2.3.0/25 dev eth0
> Where eth0 is the external interface.
> 
> Thanks,
> Robert
> 
> 

Just to follow up on my own post, I did get this to work, I had to add the
route for the subnet into the router instead of the linux machine itself.
The actual iptables command that used was:

Iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -j SNAT --to
1.1.1.2-1.1.1.63

And added the route

1.1.1.2/26 gw 1.1.1.65

Into the cisco router.

Robert