It looks like this came from the HamWan people who apparently use a lot of RFC1918 addressing, I think at first even their whole network was on RFC1918 space and they introduced net44 capability only later. However, in our network here we exclusively use net44 addresses, also for links and routers. Of course we do have appropriate firewalls in place. The first line of defense is that at the internet router, all incoming traffic is blocked by default unless the destination is from an address list of only systems that provide services that are to be visible from internet. And in the last router before the actual system there is an additional firewall that opens only certain ports for everyone, and restricts management ports to another address list that has only addresses of known operators, or at most the country subnet. This makes the result similar to using RFC1918 addressing (which provides protection because it can only be routed locally), but without the disadvantages that you mention. Anyway, I am not that much concerned about that part of the text, it will depend on local policies and we do not use that method of subnet allocation anyway. My main concern at this time is that "outsiders" (not licensed radio amateurs) apparently find our network in their search for IPv4 address space, and make requests that we have to reject. This rejection often leads to discussion (partly because there is no terminate-this-request option in the portal, a coordinator can only accept it or send it back to the requester for more detail). Therefore I think it would be best when those outsiders immediately see that this system is not for them. Rob