inside Header has the incorrect SRC)....likely because of no route policy...another discussion... Easy: when you take a default Linux system and add something like IPIP mesh with routes in the same table, and then you run services on the same system, an outgoing connect to a system within net44 will just consult the routing table, find an outgoing route and make a connection. You then have to rely on the "source address selection" done by the system, which may select your public IP as the source address. This may also be configured in the service itself (when the socket is not bound to 0.0.0.0 but to some specified address). The outgoing connect will now be routed through the IPIP tunnel, but it will have the public address as the source. To prevent this, the service would have to be bound to the net44 address, or it would have to be set as a default source address in the tunnel routes in the table. When you run a separate system as the IPIP router and an AMPRnet services host, you do not run into this problem because the services host has the proper external address within net44 and the router will not change it. But with both combined in a single host, you can still get it working correctly when you pay some attention.   Which of course has to be done when you want a single system that can both be a general-purpose internet browsing system (directly via your ISP connection) and can be an AMPRnet services host at the same time (also for services available from public internet addresses).  The routing has to be carefully set up when doing this, and setting a preferred source address is only part of that. In our network the problem you mention w.r.t. AMPRGW does not occur because internet traffic is routed directly to our gateway, not via an IPIP tunnel. The IPIP tunnel via AMPRGW only gets public internet traffic when our BGP announcement is down for some reason, that is why I kept it operational but it normally has zero traffic. So all traffic received on IPIP tunnels should be from net44 only in our case.  Unfortunately not all of it is. When I "just drop" the bad traffic it appears in a log and it appears the originators of the traffic do not notice it, so it goes on and on. As I mentioned, I sent mail to gateway owners about it, but it rarely fixes the situation. Rob