Debian 11 with pihole : network configuration information

[deHakkelaar]

Another thing that looks weird is below FQDN pihole.pihole:

@fatez

127.0.1.1 pihole.pihole pihole

Usually you configure the FQDN to be the hostname plus the DNS search/suffix domain like below:

Sudo: unable to resolve host {hostname}: Name or service not known

Figure out your hostname: pi@ph5b:~ $ hostname ph5b Figure out your DNS search/suffix domain: pi@ph5b:~ $ pihole-FTL dhcp-discover [..] domain-name: "home.dehakkelaar.nl" Edit below file so it resembles: pi@ph5b:~ $ sudo nano /etc/hosts 127.0.0.1 localhost ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters 127.0.1.1 ph5b.home.dehakkelaar.nl ph5b Check: pi@ph5b:~ $ hostname -f ph5b.home.dehakkelaar.nl

EDIT:

pi@ph5b:~ $ man hostname
[..]
       -f, --fqdn, --long
              Display  the  FQDN  (Fully  Qualified Domain Name). A FQDN
              consists of a short host name and the DNS domain name. Un‐
              less  you  are  using bind or NIS for host lookups you can
              change the FQDN and the DNS domain name (which is part  of
              the FQDN) in the /etc/hosts file. See the warnings in sec‐
              tion THE FQDN above und use hostname  --all-fqdns  instead
              wherever possible.