The upgrade from FreeBSD 10.3 to FreeBSD 11.1 is now complete
and after several hours debugging, the ipip encapsulation is
once again working.
There is a very special place in Hell reserved for people who
change system call interfaces without documenting them anywhere.
Particularly when they change the byte order of a parameter,
like packet length.
If you have any problems with things on amprgw, let me know.
- Brian