[Pool] Port 37 UDP

Ryan A. Krenzischek ryan at bbnx.net
Sat Jul 3 01:24:39 UTC 2010


Patrick,

37/UDP and 37/TCP is the standard time service that traditionally runs out 
of inetd or xinetd.  It has a base line of 1 jan 1900 instead of the 
standard EPOCH which starts 1 Jan 1970.  Information regarding the 
standard time service is found here (http://tools.ietf.org/html/rfc868) 
and http://www.nist.gov/physlab/div847/grp40/its.cfm.  Some really old 
clients using rdate use this to do a one-type sync for date/time from 
another machine.  NIST has phased out all but one server 
(time-nw.nist.gov) that will answer on 37/UDP and 37/TCP.  They plan to 
discontinue this service in the future.

Please note that the standard time service can not be used for NTP sync.

Regards,

Ryan

On Fri, 2 Jul 2010, Patrick Domack wrote:

> Date: Fri, 02 Jul 2010 18:49:34 -0400
> From: Patrick Domack <patrickdk at patrickdk.com>
> To: pool at lists.ntp.org
> Subject: [Pool] Port 37 UDP
> 
> I have noticed (as I was changing around dns and ntp on my systems) that I 
> get lots of port 37 requests.
>
> About 8 per second from private ip addresses, and 1 per 10seconds from a 
> valid ip
>
> Someone out here making horribly bad nat routers that only do tcp?
>
> 18:41:43.021572 IP 10.4.57.240.1026 > 38.117.195.101.37: UDP, length 0
> 18:41:43.084644 IP 10.1.58.238.1025 > 38.117.195.101.37: UDP, length 0
> 18:41:43.132121 IP 10.3.64.167.1026 > 38.117.195.101.37: UDP, length 0
> 18:41:43.309778 IP 10.3.59.111.1026 > 38.117.195.101.37: UDP, length 0
> 18:41:43.518093 IP 10.4.56.39.1027 > 38.117.195.101.37: UDP, length 0
> 18:41:43.617981 IP 10.18.128.60.4087 > 38.117.195.101.123: NTPv1, Client, 
> length 48
> 18:41:43.750568 IP 10.18.128.99.1442 > 38.117.195.101.123: NTPv1, Client, 
> length 48
> 18:41:43.827442 IP 10.18.128.115.1571 > 38.117.195.101.123: NTPv1, Client, 
> length 48
> 18:41:43.902925 IP 10.1.19.83.1027 > 38.117.195.101.37: UDP, length 0


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