[ntp:questions] xntp both serve and client

Steve Kostecke kostecke at ntp.org
Wed Nov 5 19:14:29 UTC 2008

On 2008-11-05, fenwayfool <peterson.russell at gmail.com> wrote:

> Is it possible to turn off xntp server functionality?


The only difference between an ntpd which is a "server" and an ntpd
which is a "client" is that the former replies to polls from other ntpds
(or other [s]ntp clients).

BTW: xntp is the name that was used for ntp version 3.*'; it is now
known as "ntp".

> That is, xntpd seems to always have port 123 open.

ntpd binds port 123 on all interfaces. Whether or not this port is
"open" depends on your host firewall, upstream firewalls, and the ntpd
access restrictions.

> This shows up on a port scan even though the system I have really only
> requires client functionality. Seems like I could restrict server
> access via the ntp.conf file but port 123 would still be open... I
> don't want random port scans to show the port as open.

Please see http://support.ntp.org/Support/AccessRestrictions to learn
about setting ntpd access restrictions.

Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/

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