General

Do you remember then time when you learned calculating subnets and all that stuff and that the teacher told you that /31 prefixes won't work because "besides net address and broadcast address, there wouldn't be any other free addresses" (unless you haven't heard about [[CIDR]] and still learnt about the classes which are obsolete for more than 10 years). Oh, well, the stuff about /31 prefix isn't quite valid anymore, as I discovered today. For almost 4 years, RFC 3021 is available, which describes a way to do IPv4 point-to-point links. As far as I found out, it is meant to be used for transfer nets, where /30 nets have been used before. This absolutely makes sense, as you won't need more than 2 nodes in a transfer net, anyway, so identifying the net and the broadcast address is quite useless.