Use a Load-Balancer or Directory Proxy Server. In many environments, the server can be run on a non-privileged port but can be hidden by a hardware load-balancer or LDAP Directory Proxy Server.
Use netfilter . The netfilter mechanism, exposed through the iptables command, can be used to automatically redirect any requests from a privileged port to the unprivileged port on which the server is listening.
To run as a non-root user but still allow connections on a privileged port, two options are available: