Q & A on Reserved ports in UNIX Q: I tried to write an echo server for a UNIX workstation in my office, but I cannot open the echo port. I receive this message: can't bind to echo port: permission denied Why doesn't it work? A: Several people have variations of this question. The problem arises because the UNIX operating system protects resources. Before you can use any port less than 1000 on a UNIX systems, you must: have superuser privilege (also known as "root") make sure no other process has the port open (only one server can offer a given service). As a practical matter, on most UNIX systems you must disable the UNIX inetd process or change the configuration file because inetd provides the echo service.