system call sets the associated fib for all sockets opened
subsequent to the call, to be that of the argument
must be greater than or equal to 0
and less than the current system maximum which
may be retrieved by the
The system maximum is set in the kernel configuration file with
.Cd options ROUTETABLES= Ns Em N
is an integer.
This maximum is capped at 65536 due to the implementation storing
the fib number in a 16-bit field in the
packet header, however it is not suggested that one use such a large number
as memory is allocated for every FIB regardless of whether it is used, and
there are places where all FIBs are iterated over.
The default fib of the process will be applied to all protocol families
that support multiple fibs, and ignored by those that do not.
The default fib for a process may be overridden for a socket with the use