El 10/8/25 a las 23:13, Grant Edwards escribió: > On 2025-08-10, Grant Taylor wrote: > >>> and it looks like I'm going to need to do that to avoid possible >>> collisions >> >> I would ask why. But you hint at some additional complications. > > I need to be able to run servers that are required to bind to > specific, well-known, reserved ports that are within the Linux > ephemeral port range. If some client connection happens to be using > one of those reserved ports, then the server will be unable to run. > > At least that's what my googling and reading have led me to > believe. Is that wrong? > > Can a server bind to a and listen on a local port that is already > in-use as the source port for a TCP connection? > > I guess I should test it... > > -- > Grant > > > > > Taking measures to avoid it is an admin task, as to assure yourself that your users don't run bittorrent clients that eats all your widthband. You can forward incoming connections from one port to another, for example forwarding incomming connections to 80 port to your proxy one 8080. The same with others Anybody can run "nc" command and use your ports, it's not needed that were taken automatically by a firefox client for example. You have tools to avoid it, between others iptables that can allow you even select which uid could use this port as with -m owner.