bindAll

Bind every loopback address this host HAS on ONE shared port, trying tries ports from start, and really give back a port we turn down.

A port counts as free only when it is free on every one of them: a half-taken port belongs to another process, and a client whose resolver picks that address would hand it our bearer token. So contention is a hard failure.

An address no interface carries can be dialed by nobody, so it was never in the set to own — configured settles that BEFORE the sweep, which leaves no exception to make afterwards. The sweep itself is still never preceded by a probing BIND: that one answers about one port at one moment, with nothing holding it true in between.

tries == 1 means that exact port or nothing: an explicit port is the caller's to own.