--dhcp-alternate-port[=<server port>[,<client port>]]

(IPv4 only) Change the ports used for DHCP from the default. If this option is given alone, without arguments, it changes the ports used for DHCP from 67 and 68 to 1067 and 1068. If a single argument is given, that port number is used for the server and the port number plus one used for the client. Finally, two port numbers allows arbitrary specification of both server and client ports for DHCP.