#1133842 libnss-resolve: libnss_resolve fails resolving PTR records for IPv4 addresses

Package:
libnss-resolve
Source:
libnss-resolve
Description:
nss module to resolve names via systemd-resolved
Submitter:
Marco Moock
Date:
2026-04-14 19:07:02 UTC
Severity:
normal
Tags:
#1133842#5
Date:
2026-04-14 18:46:58 UTC
From:
To:
Dear Maintainer,

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I installed Debian 13.4 on the Raspberry Pi. This comes with
systemd-resolve preconfigured.

nsswitch included:
hosts:          files myhostname resolve [!UNAVAIL=return] dns

I noticed that resolving the PTR records for IPv4 addresses
(3.2.1.10.in-addr.arpa) does not work if "resolve [!UNAVAIL=return]" is included in the
nsswitch.conf. If I send that query directly via DNS to the server
listed in resolv.conf (127.0.0.53), it works.

That's why I assume an issue with libnss_resolve.

I only have IPv6 upstream DNS servers set that can properly resolve the
query.

This might be related to https://github.com/systemd/systemd/issues/29069


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