Marius,
I'd like to understand the recommendation regarding using Source NAT, I am not using NAT, as all my IPs are directly routed to their hosts, and all my AMPR hosts possess 44 IP address and are routed directly. Every device on my network has a source IP in the range of 44.60.44.0/24, and knows of no other routes but other AMPR subnets and the gateway (when used) via my 44.60.44.1. Also, when using the default route, 44.0.0.1 populates in rip44 as:
44.0.0.1 dev tunl0 via 169.228.66.251 onlink.
Therefore, all AMPR networks are in-fact on my route table, including 44.0.0.1.
'44.0.0.1 via 169.228.66.251' is a valid and operational route (as removing it causes announcements not to populate). Also, 'default via 169.228.66.251' is valid as it provides connectivity to the Internet and routes to populate (since the default route is in-fact a link to the next hop, 44.0.0.1).
I understand that 44.0.0.1 is known to be un-pingable via AMPR, I have never been able to ping it. There are various reasons that could be so, but Brian would be better to explain that (looping packets sent by a rogue or misconfigured station using 44.0.0.1 as its IP are very good reasons). Please note that it would be technically improper to say it's unreachable, as we all have a route to 44.0.0.1; and we (all registered gateways) receive subnet announcements when the 44.0.0.1 route is installed.
Just because an address is not pingable, telnet-able, etc, does not mean it's invalid and in-operational (for example, for safety's sake [RFC 2003 -IP Encapsulation within IP - section 3.2], I firewall forwarding of any IP whose source matches an interface on my AMPRrouter).
You would be correct that 44.0.0.0/8 is an invalid route within AMPR, as you cannot reach subnets within AMPR without their direct route. We all confirm that we have direct routes installed to the subnets we are testing.
I have not had issues with Windows hosts pinging 44 addresses over AMPR. Before I used BIND DNS on 44.60.44.3, I used Microsoft DNS, that host worked fine (Windows DNS simply required more memory to maintain than BIND).
~Lynwood