# DNS configuration errors/issues with \`pool.ntp.org\` **URL:** \ **Category:** Server operators\ **Tags:** dns\ **Created:** [June 30, 2021, 11:32am UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039 "2021-06-30T11:32:49Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![giovane](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/giovane/32/755_2.png) [@giovane](https://community.ntppool.org/u/giovane)\ **Post date:** [June 30, 2021, 11:32am UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/1 "2021-06-30T11:32:49Z")
Folks, Digging a bit deeper here on the DNS authoritative servers setup for `pool.ntp.org`. It turns out that there are _several issues_ with it ATM, ranging from unresponsive servers to reuse of the same IP address for different NSes. You can get full reports from two great online DNS tools. I’m including here links to the experiments I ran already: 1. Using [DNSVIZ](https://dnsviz.net/d/pool.ntp.org/YNxLZw/responses/) 2. Using [Zonemaster](https://zonemaster.iis.se/en/?resultid=007295f8ad2799a7) thanks ps: thanks @marco.davids for the help too ---
**Author:** ![ask](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/ask/32/907_2.png) [@ask](https://community.ntppool.org/u/ask)\ **Post date:** [July 3, 2021, 12:29pm UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/2 "2021-07-03T12:29:42Z")
Thanks @giovane & @marco.davids – @gfk and I did talk recently about some of these. Not getting them removed from the NS records was an oversight. ---
**Author:** ![marco.davids](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/marco.davids/32/767_2.png) [@marco.davids](https://community.ntppool.org/u/marco.davids)\ **Post date:** [July 5, 2021, 8:49am UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/3 "2021-07-05T08:49:45Z")
Indeed three delegation errors seem fixed now. Thank you! For the record: these where there errors that now seem fixed: IP 199.188.48.59 in parent refers to multiple nameservers ([d.ntpns.org](http://d.ntpns.org); [g.ntpns.org](http://g.ntpns.org)). IP 199.188.48.59 in child refers to multiple nameservers ([d.ntpns.org](http://d.ntpns.org); [g.ntpns.org](http://g.ntpns.org)). IP 199.188.48.59 refers to multiple nameservers ([d.ntpns.org](http://d.ntpns.org); [g.ntpns.org](http://g.ntpns.org)). These are the remaining errors: > **[Zonemaster](https://zonemaster.iis.se/en/?resultid=6bab6d8ff301c8bb#_CONNECTIVITY)** > > Zonemaster hjälper dig att kontrollera hur din webbplats mår. Testa din DNS server och upptäck fel. ---
**Author:** ![marco.davids](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/marco.davids/32/767_2.png) [@marco.davids](https://community.ntppool.org/u/marco.davids)\ **Post date:** [July 14, 2021, 9:51am UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/4 "2021-07-14T09:51:45Z")
Follow up: A quick review[1] seems to indicate that some IP-addresses in the NS-set for [pool.ntp.org](http://pool.ntp.org) are still unresponsive: 2a05:91c0:1505:5::c924 ([c.ntpns.org](http://c.ntpns.org)) 2620:7:6000::ffff:c759:df35 ([d.ntpns.org](http://d.ntpns.org) 199.249.223.53 ([d.ntpns.org](http://d.ntpns.org)) 91.212.242.43 ([f.ntpns.org](http://f.ntpns.org)) It is also confusing that the SOA record of [pool.ntp.org](http://pool.ntp.org) has a rather variable content[2] in the MNAME field and I wonder why this is? Why not put [a.ntpns.org](http://a.ntpns.org) in it everywhere? [1] `for a in $(dig +short ns pool.ntp.org | sort); do echo -e "\033[1mServer\033[0m $a ------"; for b in $(dig +short A $a); do echo " IP: $b ---"; dig +short SOA pool.ntp.org @$b; done; done` [2] `dig +nssearch pool.ntp.org` ---
**Author:** ![gfk](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/gfk/32/1479_2.png) [@gfk](https://community.ntppool.org/u/gfk)\ **Post date:** [July 30, 2021, 2:40pm UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/5 "2021-07-30T14:40:59Z")
> [@marco.davids](#): > > A quick review[1] seems to indicate that some IP-addresses in the NS-set for [pool.ntp.org](http://pool.ntp.org) are still unresponsive: > > 2a05:91c0:1505:5::c924 ([c.ntpns.org](http://c.ntpns.org)) > 2620:7:6000::ffff:c759:df35 ([d.ntpns.org](http://d.ntpns.org) > 199.249.223.53 ([d.ntpns.org](http://d.ntpns.org)) > 91.212.242.43 ([f.ntpns.org](http://f.ntpns.org)) Hello Marco and thanks for the analyses. Here’s what’s going on: - 2a05:91c0:1505:5::c924 is fixed (actually changed to 2a05:91c0:1505:5:: ) - 91.212.242.43 has been removed permanently from DNS - 199.249.223.53/2620:7:6000::ffff:c759:df35 had crashed, operator has been notified, should be back in a few hours. ---
**Author:** ![marco.davids](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/marco.davids/32/767_2.png) [@marco.davids](https://community.ntppool.org/u/marco.davids)\ **Post date:** [July 30, 2021, 4:35pm UTC](https://community.ntppool.org/t/dns-configuration-errors-issues-with-pool-ntp-org/2039/6 "2021-07-30T16:35:00Z")
> [@gfk](#): > > Here’s what’s going on: Confirmed! Thank you! [https://zonemaster.iis.se/?resultid=12182bd01f32f739](https://zonemaster.iis.se/?resultid=12182bd01f32f739) UPDATE 20210801: > [@](#): > > 199.249.223.53/2620:7:6000::ffff:c759:df35 had crashed, operator has been notified, should be back in a few hours. That was two days ago. Apparently we have to be a little more patient? 😉