Dear Maintainer,

After installing NIS on a fresh install on Debian 13 ybbind.service fails
to start during boot. Or after boot using systemctl.

Error message:
jlinkels@donald-pc:/etc$ systemctl status ypbind.service
× ypbind.service - NIS Binding Service
     Loaded: loaded (/usr/lib/systemd/system/ypbind.service; enabled; preset: enabled)
     Active: failed (Result: exit-code) since Sat 2026-02-28 17:17:36 AST; 10s ago
   Duration: 14min 19.578s
 Invocation: 8c7ee982fbdd4b4a93f1d281574d7bda
    Process: 3864 ExecStartPre=/bin/domainname -F /etc/defaultdomain (code=exited, status=1/FAILURE)
   Mem peak: 1.7M
        CPU: 9ms

The reason being the file /etc/defaultdomain is not present.
Creating the file /etc/defaultdomain solves the problem.

In earlier debian versions (the last one I tested is Bullseye) this
did not occur.

dkpg-reconfigure does not ask for anything.

Setting kernel.domainname through a script in /etc/sysctl.d
does correctly set /proc/sys/kernel/domainname. But it does not
solve the problem as ybbind.service tries to set the domain name
from the /etc/defaultdomain file

contents of yp.conf:
jlinkels@donald-pc:/etc/sysctl.d$ cat /etc/yp.conf
# ypserver ypserver.network.com
domain nis.lhome server 192.168.110.12

contents of /etc/defaultdomain:
jlinkels@donald-pc:/etc/sysctl.d$ cat /etc/defaultdomain
nis.lhome