“connectd -n” reports:
Your Router has sub-optimal NAT mapping, you may have reduced performance.
but I can’t find any explanation of this phrase in the documentation. Does the software prefer a NAT router to maintain the source port number across the NAT? If so, why does source port randomization imply reduced performance?
A subsidiary question: is it the case that a P2P connection requires that at least one end of the link has a public non-NAT IP address?