Guys, My request for the 123/UDP and 123/TCP port number predated the IANA some twenty years ago. I wanted to be sure some ill-mannered rascal didn't poach on 123/TCP. My reasoning was that TCP might someday be used for monitoring purposes. For the basic on-wire protocol, UDP is the only choice. Should your network administrator object, he/she gets to use TCP/DAYTIME or TCP/TIME. You might have trouble finding a server that supports that. NIST has stood down TCP on the busiest servers, as it is a clogging vulnerability with thousands of users.
Dave Shaochun Wang wrote: > Danny Mayer wrote: > >> Shaochun Wang wrote: >> >>> The stupid net administrator of my institute blocked all UDP datagram >>> in the firewall. I know that NTP uses UDP to do its work, but is it >>> possible to let ntpd use TCP? >> >> >> No. You cannot "let" ntpd use TCP. NTP is a UDP-only protocol. Talk to >> your net admin. Maybe he can set up a NTP server on the firewall. >> >> Danny > > > But why the following entry exists in /etc/services file? > > ntp 123/tcp # Network Time Protocol > _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
