Recently I noticed on a freshly installed server that there was no command called nslookup. Luckily, Debian-like distributions have the apt-file tool.
This makes it possible to search for applications that are not yet installed but are in principle available in the APT repository. The command
apt-file search nslookup
quickly shed light on the matter and delivered the following output:
bash-completion: /usr/share/bash-completion/completions/nslookup
bind9-doc: /usr/share/doc/bind9-doc/arm/man.nslookup.html
dnsutils: /usr/bin/nslookup
dnsutils: /usr/share/man/man1/nslookup.1.gz
exim4-doc-html: /usr/share/doc/exim4-doc-html/spec_html/ch-the_dnslookup_router.html
fpc-source-3.0.4: /usr/share/fpcsrc/3.0.4/packages/fcl-net/examples/cnslookup.pp
libnet-nslookup-perl: /usr/share/doc/libnet-nslookup-perl/changelog.Debian.gz
libnet-nslookup-perl: /usr/share/doc/libnet-nslookup-perl/copyright
libnet-nslookup-perl: /usr/share/lintian/overrides/libnet-nslookup-perl
libxpa-dev: /usr/share/man/man3/xpanslookup.3.gz
So it was clear that the dnsutils package had to be installed
afterwards. Calling
apt-get install dnsutils
was enough and the nslookup tool was already available on my server.
If apt-file itself is not yet installed, it can be installed beforehand using
apt-get install apt-file
It is important that the cache is set up immediately afterwards. This is done using
apt-file update