RE: Is there a way....

["Rob Sterenborg" <rob@sterenborg.info>]

> Hi,
> 
>   I want to use Linux to do NAT between some 192.168.x.x addresses
> in a routed network on one side and a single 10.0.0.x/24 on the other
> side. I want to do one-to-one NAT but in a dynamic way... such that a
> calling address is NATed into the next available 10.0.0.x/24.... in a
> round robin sort of way... IS there a way to do this using NETFILTER??
> If not NETFILTER, then how?? 
> 
>   This sort of thing is common in many-to-one NAT (port-address
> translation)... but I need each call to come from a separate NATed IP
> address to support my application (TN3270 session)... It's OK to reuse
> addresses after a call (session) is complete, but each session needs
> to come from it's own fixed (for the duration of the session) IP
> address.... 
> 
>   The exact application that I am trying to support is connecting to
> an IBM mainframe from random hosts in a routed network via an
> Attachmate gateway where calling addresses are mapped into terminal
> sessions on a 1:1 basis.... Port address translation won't work
> because all calls appear to eminate from the single IP address.... I
> need to do 1:1 NAT but only on a temporary basis where once a call is
> complete the NAT address can be used by another caller...
> 
>   Clues? Suggestions? Examples?

Have you tried the NETMAP target ? Using NETMAP I don't see a reason to
have to reuse IP addresses for NAT because you can NAT a complete subnet
1:1 with NETMAP.
http://www.netfilter.org/projects/patch-o-matic/pom-base.html#pom-base-N
ETMAP


Gr,
Rob