MasterServer

q4master.idsoftware.com:27650

Get Server List
0000   ff ff 67 65 74 53 65 72 76 65 72 73 00 55 00 02  ..getServers.U..
0010   80 00 00 00 00                                   .....

Default Server Port

28004

Server Query Port

Same port as server port.