NTP
Network Time Protocol
Port: 123
https://tools.ietf.org/pdf/rfc5905.pdf
https://en.wikipedia.org/wiki/Network_Time_Protocol
Generate NTP Query/Response with netcat
echo -ne '\xE3\x00\x06\xEC\x31\x4E\x31\x34\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' | nc -xu time.nist.gov 123
Sent 48 bytes to the socket
00000000 E3 00 06 EC 31 4E 31 34 00 00 00 00 00 00 00 00 ....1N14........
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Received 48 bytes from the socket
00000000 24 01 06 E3 00 00 00 00 00 00 00 00 41 43 54 53 $...........ACTS
00000010 DB 7C 1C DC 4B E0 57 2D 00 00 00 00 00 00 00 00 .|..K.W-........
00000020 DB 7C 1C E4 49 93 89 E4 DB 7C 1C E4 49 94 47 B5 .|..I....|..I.G.