To all I have checked the issue more deeply with two different routers and two different homes that get internet feed My home use Cable modem that on its DMZ sit a MikroTik Router . Even when the cable modem set to no DMZ at all i still get amprnet traffic to my home and all is working fine but if i point on the DMZ to a PC that have a web server and from outside world surf to my publiic IP i get the web server respond but if i shut the DMZ the web server is not answering to requests anymore so the DMZ mechanism, is functioning but it turn out that for the ipip tunnel the DMZ dont effect at all it has been tested with two different modems in two different internet feeds and two AMPRNET networks my cable modem modem work as a Router and do NAT for the Internet to Private addresses (192.168.1.x) and the MOkroTik router sit on this address and do the IPIP tunnel to UCSD The other home use modem that is used as a transparent mode and connected to first mikrotik that makes the NAT for the Private network (10.0.0.x) and after this modem there is additional mikrotik that do the IPIP to UCSD and it work without any DMZ or Port redirection I dont know to explain it but that is the facts and its hard to argue with that currently at my home the DMZ point to a computer that do Echolink bridge to our NatoinWide DMR system and not to the router that do the IPIP and i have a working AMPRNET .... Regards Ronen -4Z4ZQ ________________________________ From: 44Net <44net-bounces+ronenp=hotmail.com(a)mailman.ampr.org> on behalf of Michael Cullen via 44Net <44net(a)mailman.ampr.org> Sent: Tuesday, May 21, 2019 7:09 AM To: AMPRNet working group Cc: Michael Cullen Subject: Re: [44net] UCSD tunnel behing NAT and Firewall setting ? _________________________________________ 44Net mailing list 44Net(a)mailman.ampr.org https://mailman.ampr.org/mailman/listinfo/44net