You can filter incoming traffic based on TCP and User Datagram Protocol (UDP) port numbers either dynamically by using dynamic port filtering or statically by using the TCPIP FILTERFRAMES command. If the FILTERFRAMES command is enabled for a port or range of ports, then those ports are always closed and no traffic can reach the MCP environment. If the FILTERFRAMES command is disabled for a port or range of ports (the default), then dynamic port filtering can be used as described in the following topic.