On CentOS 7 default, you can’t use dig or host command:
[root@tutorialspots ~]# dig -bash: dig: command not found
How to install dig on CentOS 7?
The DIG tool and the HOST tool are a part of the BIND Utilities so you need to install them. To install the BIND Utilities, type the following:
yum install -y bind-utils
Result:
[root@tutorialspots ~]# yum install -y bind-utils Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: repos-tx.psychz.net * epel: kdeforge2.unl.edu * extras: centos.den.host-engine.com * ius: dfw.mirror.rackspace.com * nux-dextop: mirror.li.nux.ro * remi-safe: mirror.bebout.net * updates: repo.miserver.it.umich.edu Resolving Dependencies --> Running transaction check ---> Package bind-utils.x86_64 32:9.9.4-72.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: bind-utils x86_64 32:9.9.4-72.el7 base 206 k Transaction Summary ================================================================================ Install 1 Package Total download size: 206 k Installed size: 431 k Downloading packages: bind-utils-9.9.4-72.el7.x86_64.rpm | 206 kB 00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : 32:bind-utils-9.9.4-72.el7.x86_64 1/1 Verifying : 32:bind-utils-9.9.4-72.el7.x86_64 1/1 Installed: bind-utils.x86_64 32:9.9.4-72.el7 Complete!
Done!, now you can use both dig and host command:
[root@tutorialspots ~]# host
Usage: host [-aCdlriTwv] [-c class] [-N ndots] [-t type] [-W time]
[-R number] [-m flag] hostname [server]
-a is equivalent to -v -t ANY
-c specifies query class for non-IN data
-C compares SOA records on authoritative nameservers
-d is equivalent to -v
-l lists all hosts in a domain, using AXFR
-i IP6.INT reverse lookups
-N changes the number of dots allowed before root lookup is done
-r disables recursive processing
-R specifies number of retries for UDP packets
-s a SERVFAIL response should stop query
-t specifies the query type
-T enables TCP/IP mode
-v enables verbose output
-w specifies to wait forever for a reply
-W specifies how long to wait for a reply
-4 use IPv4 query transport only
-6 use IPv6 query transport only
-m set memory debugging flag (trace|record|usage)
Now you have these files:
[root@tutorialspots ~]# rpm -ql bind-utils /etc/trusted-key.key /usr/bin/dig /usr/bin/host /usr/bin/nslookup /usr/bin/nsupdate /usr/share/man/man1/dig.1.gz /usr/share/man/man1/host.1.gz /usr/share/man/man1/nslookup.1.gz /usr/share/man/man1/nsupdate.1.gz
