NAT-Problems (further informations)

[Andreas Grewe]

I figured out some new informations on my NAT problem:

It seems that my NAT box correctly translates inside NAT addresses  
to outside NAT-Pool addresses (e.g. 192.168.100.52 to  
193.96.50.235) but it don't answer on any ARP-requests of the  
echoing host.

Do I have to install any ARP Proxy (if so, why isn't it integrated  
in netfilter or why isn't there any installation hint that I have  
to do so)?

Greets
Andreas Grewe