# Reverse DNS lookups

**URL:** <https://community.ntppool.org/t/reverse-dns-lookups/2017>\
**Category:** Server operators\
**Tags:** dns\
**Created:** [May 27, 2021, 10:26am UTC](https://community.ntppool.org/t/reverse-dns-lookups/2017 "2021-05-27T10:26:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**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:** [May 27, 2021, 10:26am UTC](https://community.ntppool.org/t/reverse-dns-lookups/2017/1 "2021-05-27T10:26:00Z")

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Does anyone know why NTP-daemons tend to do reverse DNS lookups (PTR) sometimes?

Is it a problem when this doen’s work (such as is the case with ntp.ufe.cz currently)?

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**Author:** ![ddrown](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/ddrown/32/11_2.png) [@ddrown](https://community.ntppool.org/u/ddrown)\
**Post date:** [December 18, 2021, 4:09pm UTC](https://community.ntppool.org/t/reverse-dns-lookups/2017/2 "2021-12-18T16:09:58Z")

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Tools like ntpq and chronyc will lookup the reverse DNS. This is just cosmetic if the IP doesn’t resolve. It can cause the tools to wait on a timeout if the reverse DNS servers don’t respond at all.