( NTP JCB 09:54 11/17/10) : ntp-server \ h# 02830a00. \ ip# 91.189.94.4 \ time.ubuntu ip# 17.151.16.20 \ time.apple.com ; : ntp-request d# 123 d# 9999 ntp-server net-my-ip 2over arp-lookup ( dst-port src-port dst-ip src-ip *ethaddr ) udp-header h# 2304 mac-pkt-, h# 04ec mac-pkt-, d# 6 mac-pkt-,0 d# 4 mac-pkt-,0 \ originate d# 4 mac-pkt-,0 \ reference d# 4 mac-pkt-,0 \ receive \ d# 4 mac-pkt-,0 \ transmit time@ mac-pkt-d, d# 2 mac-pkt-,0 udp-wrapup mac-send ; : ntp-handler IP_PROTO_UDP ip-isproto ETH.IP.UDP.SOURCEPORT packet@ d# 123 = and ETH.IP.UDP.DESTPORT packet@ d# 9999 = and if ETH.IP.UDP.NTP.TRANSMIT packetd@ setdate time@ ETH.IP.UDP.NTP.ORIGINATE packetd@ d- setdelay then ;