With the BGP advertisement my subnet is reachable via internet and can reach anywhere via internet. Other 44 networks can reach my subnet as long as they are also advertised via BGP or have appropriate NAT rules to allow internet access. I can reach any BGP advertised 44 net addresses. However, I should not be able to reach any non-BGP advertised 44 net addresses unless there is a gateway (at USCD?) that allows for access to IPIP only 44 networks from 44 networks.
I guess I don’t know the network topology of the 44 net or the functions that are provided at the UCSD gateway.
I assumed that in order to reach IPIP only networks I would have to also establish IPIP tunnelling from each 44 host or gateway using subnets of my BGP advertised subnet.
When the system that handles the traffic that comes in on your BGP advertised route also has a public IP address and is made member of the IPIP mesh for the same subnet it advertises on BGP, you can talk to everyone that is on the IPIP mesh. They will send traffic for you via the IPIP tunnel that they establish because you are in the list maintained via portal.ampr.org and transmitted using RIP from the gateway at UCSD. You then only use IPIP for traffic between hosts on the IPIP mesh, not for the remainder of traffic to and from internet.
Rob