Yes, but you may have to punch holes in the firewall _as well_. I
don't
think selinux security context would override any local firewall rules
which (as they stand today) lock down all ports that aren't explicitly
enabled for a service.
Thats why you should be using selinux to prevent unwanted port bindings
system wide. Disable firewalling in this case. Or at least limit it to
ports <1024 or something.
There's still the annoying question of ports the *kernel itself* is
listening to. NFS serving likes to do this, and use random ports just
above 1024 to do it. ;P