Question

I’m writting an UDP server for a game.
Do you know if is possible to have multisocket in UDP on one port ? or I must use dynamic port (one socket = one port) ?

thanks

Answer 1

See Using SO_REUSEADDR…:

Using SO_REUSEADDR

The SO_REUSEADDR socket option allows a socket to forcibly bind to a
port in use by another socket. The second socket calls setsockopt with
the optname parameter set to SO_REUSEADDR and the optval parameter set
to a boolean value of TRUE before calling bind on the same port as the
original socket. Once the second socket has successfully bound, the
behavior for all sockets bound to that port is indeterminate. For
example, if all of the sockets on the same port provide TCP service,
any incoming TCP connection requests over the port cannot be
guaranteed to be handled by the correct socket — the behavior is
non-deterministic. A malicious program can use SO_REUSEADDR to
forcibly bind sockets already in use for standard network protocol
services in order to deny access to those service. No special
privileges are required to use this option.

Bonus reading: What exactly does SO_REUSEADDR do? .