Command host and dig are available on Centos 5, but they are missing on Centos 6 and Centos 7. You can’t install them with yum command like
[root@tutorialspots home]# yum install dig Loaded plugins: fastestmirror Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast base | 3.6 kB 00:00 epel/x86_64/metalink | 5.7 kB 00:00 epel | 4.3 kB 00:00 extras | 3.4 kB 00:00 nginx | 2.9 kB 00:00 remi | 2.9 kB 00:00 remi-php56 | 2.9 kB 00:00 remi-safe | 2.9 kB 00:00 updates | 3.4 kB 00:00 (1/7): extras/7/x86_64/primary_db | 165 kB 00:00 (2/7): epel/x86_64/updateinfo | 628 kB 00:00 (3/7): updates/7/x86_64/primary_db | 7.8 MB 00:00 (4/7): epel/x86_64/primary_db | 4.2 MB 00:00 (5/7): remi-php56/primary_db | 200 kB 00:00 (6/7): remi-safe/primary_db | 531 kB 00:01 (7/7): remi/primary_db | 1.5 MB 00:01 Determining fastest mirrors * base: ftp.iij.ad.jp * epel: ftp.iij.ad.jp * extras: ftp.iij.ad.jp * remi: mirrors.thzhost.com * remi-php56: mirrors.thzhost.com * remi-safe: mirrors.thzhost.com * updates: ftp.iij.ad.jp No package dig available. Error: Nothing to do
But we can use this command to install host and dig
yum install bind-utils jwhois
Result:
[root@tutorialspots home]# yum install bind-utils jwhois Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: ftp.iij.ad.jp * epel: ftp.iij.ad.jp * extras: ftp.iij.ad.jp * remi: mirrors.thzhost.com * remi-php56: mirrors.thzhost.com * remi-safe: mirrors.thzhost.com * updates: ftp.iij.ad.jp Resolving Dependencies --> Running transaction check ---> Package bind-utils.x86_64 32:9.9.4-29.el7_2.4 will be installed --> Processing Dependency: bind-libs = 32:9.9.4-29.el7_2.4 for package: 32:bind- utils-9.9.4-29.el7_2.4.x86_64 --> Processing Dependency: liblwres.so.90()(64bit) for package: 32:bind-utils-9. 9.4-29.el7_2.4.x86_64 --> Processing Dependency: libisccfg.so.90()(64bit) for package: 32:bind-utils-9 .9.4-29.el7_2.4.x86_64 --> Processing Dependency: libisccc.so.90()(64bit) for package: 32:bind-utils-9. 9.4-29.el7_2.4.x86_64 --> Processing Dependency: libisc.so.95()(64bit) for package: 32:bind-utils-9.9. 4-29.el7_2.4.x86_64 --> Processing Dependency: libdns.so.100()(64bit) for package: 32:bind-utils-9.9 .4-29.el7_2.4.x86_64 --> Processing Dependency: libbind9.so.90()(64bit) for package: 32:bind-utils-9. 9.4-29.el7_2.4.x86_64 ---> Package jwhois.x86_64 0:4.0-45.el7 will be installed --> Processing Dependency: libidn2.so.0(IDN2_0.0.0)(64bit) for package: jwhois-4 .0-45.el7.x86_64 --> Processing Dependency: libidn2.so.0()(64bit) for package: jwhois-4.0-45.el7. x86_64 --> Running transaction check ---> Package bind-libs.x86_64 32:9.9.4-29.el7_2.4 will be installed --> Processing Dependency: bind-license = 32:9.9.4-29.el7_2.4 for package: 32:bi nd-libs-9.9.4-29.el7_2.4.x86_64 ---> Package libidn2.x86_64 0:0.10-2.el7 will be installed --> Running transaction check ---> Package bind-license.noarch 32:9.9.4-29.el7_2.3 will be updated --> Processing Dependency: bind-license = 32:9.9.4-29.el7_2.3 for package: 32:bi nd-libs-lite-9.9.4-29.el7_2.3.x86_64 ---> Package bind-license.noarch 32:9.9.4-29.el7_2.4 will be an update --> Running transaction check ---> Package bind-libs-lite.x86_64 32:9.9.4-29.el7_2.3 will be updated ---> Package bind-libs-lite.x86_64 32:9.9.4-29.el7_2.4 will be an update --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: bind-utils x86_64 32:9.9.4-29.el7_2.4 updates 200 k jwhois x86_64 4.0-45.el7 epel 116 k Installing for dependencies: bind-libs x86_64 32:9.9.4-29.el7_2.4 updates 1.0 M libidn2 x86_64 0.10-2.el7 epel 96 k Updating for dependencies: bind-libs-lite x86_64 32:9.9.4-29.el7_2.4 updates 724 k bind-license noarch 32:9.9.4-29.el7_2.4 updates 82 k Transaction Summary ================================================================================ Install 2 Packages (+2 Dependent packages) Upgrade ( 2 Dependent packages) Total download size: 2.2 M Is this ok [y/d/N]: y Downloading packages: Delta RPMs disabled because /usr/bin/applydeltarpm not installed. (1/6): bind-license-9.9.4-29.el7_2.4.noarch.rpm | 82 kB 00:00 (2/6): bind-libs-9.9.4-29.el7_2.4.x86_64.rpm | 1.0 MB 00:00 (3/6): jwhois-4.0-45.el7.x86_64.rpm | 116 kB 00:00 (4/6): bind-utils-9.9.4-29.el7_2.4.x86_64.rpm | 200 kB 00:00 (5/6): bind-libs-lite-9.9.4-29.el7_2.4.x86_64.rpm | 724 kB 00:00 (6/6): libidn2-0.10-2.el7.x86_64.rpm | 96 kB 00:00 -------------------------------------------------------------------------------- Total 6.5 MB/s | 2.2 MB 00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Updating : 32:bind-license-9.9.4-29.el7_2.4.noarch 1/8 Installing : 32:bind-libs-9.9.4-29.el7_2.4.x86_64 2/8 Installing : libidn2-0.10-2.el7.x86_64 3/8 Installing : jwhois-4.0-45.el7.x86_64 4/8 Installing : 32:bind-utils-9.9.4-29.el7_2.4.x86_64 5/8 Updating : 32:bind-libs-lite-9.9.4-29.el7_2.4.x86_64 6/8 Cleanup : 32:bind-libs-lite-9.9.4-29.el7_2.3.x86_64 7/8 Cleanup : 32:bind-license-9.9.4-29.el7_2.3.noarch 8/8 Verifying : 32:bind-license-9.9.4-29.el7_2.4.noarch 1/8 Verifying : libidn2-0.10-2.el7.x86_64 2/8 Verifying : jwhois-4.0-45.el7.x86_64 3/8 Verifying : 32:bind-libs-lite-9.9.4-29.el7_2.4.x86_64 4/8 Verifying : 32:bind-utils-9.9.4-29.el7_2.4.x86_64 5/8 Verifying : 32:bind-libs-9.9.4-29.el7_2.4.x86_64 6/8 Verifying : 32:bind-license-9.9.4-29.el7_2.3.noarch 7/8 Verifying : 32:bind-libs-lite-9.9.4-29.el7_2.3.x86_64 8/8 Installed: bind-utils.x86_64 32:9.9.4-29.el7_2.4 jwhois.x86_64 0:4.0-45.el7 Dependency Installed: bind-libs.x86_64 32:9.9.4-29.el7_2.4 libidn2.x86_64 0:0.10-2.el7 Dependency Updated: bind-libs-lite.x86_64 32:9.9.4-29.el7_2.4 bind-license.noarch 32:9.9.4-29.el7_2.4 Complete!
Now, you can use two commands host and dig
[root@tutorialspots home]# 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)
[root@tutorialspots home]# dig
; <<>> DiG 9.9.4-RedHat-9.9.4-29.el7_2.4 <<>>
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11792
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;. IN NS
;; ANSWER SECTION:
. 435881 IN NS k.root-servers.net.
. 435881 IN NS d.root-servers.net.
. 435881 IN NS h.root-servers.net.
. 435881 IN NS l.root-servers.net.
. 435881 IN NS c.root-servers.net.
. 435881 IN NS f.root-servers.net.
. 435881 IN NS a.root-servers.net.
. 435881 IN NS b.root-servers.net.
. 435881 IN NS g.root-servers.net.
. 435881 IN NS m.root-servers.net.
. 435881 IN NS j.root-servers.net.
. 435881 IN NS e.root-servers.net.
. 435881 IN NS i.root-servers.net.
;; Query time: 1 msec
;; SERVER: 108.61.10.10#53(108.61.10.10)
;; WHEN: Sat Oct 01 16:59:48 ICT 2016
;; MSG SIZE rcvd: 239
