[ntp:questions] OT: Solaris help - TOD service

Martin Burnicki martin.burnicki at meinberg.de
Fri Jun 13 09:26:37 UTC 2008

David J Taylor wrote:

> David Woolley wrote:
>> Martin Burnicki wrote:
>>> I'm not familiar wit TOD, but just a few words to inetd:
>> Note that the really basic time services like daytime are implemented
>> internally within inetd; inetd is the time server for those protocols.
>> I don't know what is meant by TOD here, but it might actually mean the
>> ASCII or binary time provided by inetd.
> Thanks, David and Martin.
> As I understand it, TOD here refers to a cable modem making a TCP or UDP
> request to port 13 on a server.

Huh, port 13 is used by the "daytime" protocol which returns date and local
time in human readable format which is not even well-defined, e.g.:

# telnet gateway 13
13 JUN 2008 11:08:43 CEST

# telnet time-a.nist.gov 13
54630 08-06-13 09:08:53 50 0 0  24.2 UTC(NIST) *

You see gateway (a local Linux machine) returns quite a different string on
the daytime port than one of the NIST time servers. This is why IMHO the
daytime protocol is not generally usable for automated time

The old "time" protocol using port 37 on the other hand returns UTC time in
machine readable format, which is much easier to handle for automated time
> Is there any good reason for inetd "to be switched off as a security
> measure"?  Could the TOD service be provided stand-alone, instead of
> within inetd?  Perhaps not....

Generally it's good to disable all services which are not needed. However,
if the inetd has no known security problems it should be no problem to have
it running to provided required services. I'm sure the OS can be configured
to start inetd.

> Of course, a more relevant question could be:  Why aren't the cable modems
> using NTP?  My cable modem is a Motorola SB5101E, by the way.

Very simple devices may not even require the accuracy of NTP, and the "time"
protocol would be sufficient. The specific question for me is: why does it
use the  daytime protocol instead of the time protocol or NTP?

Martin Burnicki

Meinberg Funkuhren
Bad Pyrmont

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