These extensions can be used if `--protocol udp' is specified. It provides the following options: .TP .BR "--source-port " "[!] \fIport\fP[:\fIport\fP]" Source port or port range specification. See the description of the .B --source-port option of the TCP extension for details. .TP .BR "--destination-port " "[!] \fIport\fP[:\fIport\fP]" Destination port or port range specification. See the description of the .B --destination-port option of the TCP extension for details.