But but... that does not work.
I tested it, and Brian confirmed that amprgw can not route packets out to the Internet to the BGP 44/8 sites, unless those sites are also reachable via an IPIP mesh. The technical reason is that the first upstream router between amprgw and the Internet has a static 44/8 route towards amprgw, and does not have the full Internet BGP table which would contain more specific routes to the BGP-only sites.
The BGP-enabled sites currently need to be present also in the IPIP table, and have (at least) an IPIP decapsulation gateway, so that other regular gateways can transmit packets to them. amprgw currently cannot act as a relay.
Yes, actually I know but I thought the routing loop at UCSD would be temporary. OTOH those BGP-but-no-IPIP-guys are breaking the AMPRnet and MUST fix their installation!
Also, it's more optimal to transmit the packets directly using a tunnel instead of trying to route via amprgw, even if it worked.
True.