| .TP | |
| .BR "--mac-source " "[!] \fIaddress\fP" | |
| Match source MAC address. It must be of the form XX:XX:XX:XX:XX:XX. | |
| Note that this only makes sense for packets coming from an Ethernet device | |
| and entering the | |
| .BR PREROUTING , | |
| .B FORWARD | |
| or | |
| .B INPUT | |
| chains. |