Networks announced via BGP to the Internet without an IPIP gateway entry won't be reachable from within 44net including the AMPRGW. This has been explained and discussed several times over here, BGP announced network must also have an IPIP gateway entry in to be reachable from Internet AND 44net. This means that you will have to provide a non-44net IP address as IPIP endpoint.
It's not a problem if 44net addresses cannot route to 44.24.221.0/24. It is *only* used as an anycast IPIP gateway for 44.24.240.0/20. We expect to see source addresses from the various ISPs around the world, not 44net. These ISPs should have no problem sending IPIP packets to 44.24.221.0/24, regardless of any funky 44net issues.
I repeat the AMPR GW is unable to route to 44net addresses announced via BGP. The AMPR GW can only route to non 44net addresses. So you cannot enter a 44net address as endpoint for IPIP tunnel.
BTW, it is *NOT* "a good thing" to route 44net addresses via BGP but not via IPIP mesh.
The ONLY solution for this is to use a non 44net address as the anycast destination for the IPIP tunnel for network 44.24.240.0/20.
73 de Marc