On Thu, 10 Apr 2014, Neil Johnson wrote:
In order allow hosts in the IP-IP tunnel system
reach/be reachable
to/from the Internet, I believe the default route has to be to
amprgw.sysnet.ucsd.edu.
Actually, no, not the default route. If the default route pointed to
amprgw, you could not send encapsulated packets to any other gateway at
all. The default route is applied to the IPIP packet after encapsulation -
it needs to point to your local upstream Internet router.
Some sites will have to route packets which have both (1) source
address within their 44.x.y/z subnet and (2) destination address outside
44/8, to amprgw, since their local upstream Internet provider drops
outgoing packets which have a source address within 44/8.
That's quite different from both the default route, or routing packets
having destination address within 44/8.
- Hessu