[ntp:questions] "Trapping" in ntpd

Steve Kostecke kostecke at ntp.org
Wed Oct 3 14:54:11 UTC 2007


On 2007-10-03, Rob <pse at nospam.com> wrote:

> The readme also has an important warning ---
>
> "Please think twice before starting remote XNTP daemons!!! Monitoring
> may increase the load of the daemon monitored and may increase the
> network load significantly"

This is a bit exagerated.

> As a result, in my view, it is important to have "notrap" and/or
> "noquery" on each restrict line in your ntp.conf.

A properly chosen default restriction will, in many circustances,
eliminate the need to clutter your ntp.conf file with redundant restrict
lines.

If you are serving time to others it may be considered unfriendly to
block them from viewing information about your ntpd.
Would you trust a time source that you could not inspect?

BTW In case anyone is interested ... here's a sample ntptrap message:

| Trap 1 associd 10260:
| config=1,
| authenable=1, authentic=1, srcadr=2001:4f8:*:*:*:*:*:*,
| srcport=123, dstadr=2001:*:*:*::2, dstport=123, leap=0, hmode=3,
| stratum=2, ppoll=6, hpoll=6, precision=-18, rootdelay=1.984,
| rootdispersion=25.223, refid=204.123.2.5, reftime=0xcaae2227.4466ef93,
| org=0xcaae26f2.4897206a, rec=0xcaae26f2.56bca9cd,
| xmt=0xcaae26f2.3ace3ee8, reach=0x0, unreach=1, timer=2, delay=0.000,
| offset=0.000, jitter=0.000, dispersion=15937.500, keyid=2942406510,
| filtdelay= 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00,
| filtoffset= 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00, pmode=4,
| received=1838, sent=3190,
| filtdisp= 16000.00 16000.00 16000.00 16000.00 16000.00 16000.00 \
| 	16000.00 16000.00,
| flash=0x0, ttl=0,
| peer_var_list="config,authenable,authentic,srcadr,srcport,dstadr, \
| 	dstport,leap,hmode,stratum,ppoll, hpoll,precision,rootdelay, \
| 	rootdispersion,refid,reftime,org,rec,xmt,reach,unreach,timer, \
| 	delay,offset,jitter,dispersion,keyid,filtdelay=,filtoffset=, \
| 	pmode,received,sent,filtdisp=,flash,ttl,peer_var_list,flags, \
| 	hostname,valid,initsequence,initkey,timestamp,signature,trust"
| 
| ===============
|
| hostname(209.0.0.0) = "unknown.Level3.net"
| Wed Oct  3 10:34:26 2007  hostname.my.domain trap#1 peer 10260 [2001] \
|	unknown.Level3.net event_reach 

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




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