Question

One of my stand-alone java applications (no sources available) picks random-available port to listen on.
At this stage I assume it uses getaddrinfo system call to obtain addresses to bind against.

Since I’m maintaining hundreds of various servers with assigned ports, the black app sometimes kicks in and pick one of ‘the assigned’ ports, which cause my small servers to fail on startup…

I’m wondering is there a way to restrict number of ports proposed by the OS?
Would be mostly interested in system config solutions,
but if there are no other solutions I’m also able to hack bind()/getaddrinfo (this would require some hits as well … )

thanks

Answer 1

You must be able to control it from proc entries – For example, here is a system wide setting :

/proc/sys/net/ipv4/ip_local_port_range

You can modify them. Or there may be utilities available for the same purpose.