Q. How do I setup DNS Lookup under any Linux distribution ?
A. When an application (such as mail client or browser) makes a request which requires a DNS lookup, such programs send a resolution request to the local DNS resolver in the local operating system, which in turn handles the communications required. Under Linux resolver is configured via /etc/resolv.conf file. Open this file as a root user, enter:
# vi /etc/resolv.conf
Append or modify as follows into the file:
search nixcraft.com
nameserver 4.2.1.1
nameserver 4.2.1.2
nameserver 4.2.1.3
Save and close the file. Replace nixcraft.com with your actual domain name. 4.2.1.1 is first name server address. Save and close the file. Test setup, enter:
$ host cyberciti.com
$ host -t ns cyberciti.com
Sample output:
cyberciti.com name server ns2.nixcraft.net. cyberciti.com name server ns1.nixcraft.net. cyberciti.com name server ns3.nixcraft.net.
🐧 3 comments so far... add one ↓
| Category | List of Unix and Linux commands |
|---|---|
| File Management | cat |
| Firewall | Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04 |
| Network Utilities | dig • host • ip • nmap |
| OpenVPN | CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04 |
| Package Manager | apk • apt |
| Processes Management | bg • chroot • cron • disown • fg • jobs • killall • kill • pidof • pstree • pwdx • time |
| Searching | grep • whereis • which |
| User Information | groups • id • lastcomm • last • lid/libuser-lid • logname • members • users • whoami • who • w |
| WireGuard VPN | Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04 |
A better setup is
nameserver 4.2.1.1
nameserver 4.2.1.2
nameserver 4.2.1.3
option rotate
option timeout:1
‘rotate’ sets RES_ROTATE in _res.options, which causes round robin selection of nameservers from among those listed.
‘timeout’ sets the amount of time the resolver will wait for a response from a remote name server before retrying the query via a different name server.
+1 to Known, this just saved my ass
A better setup is
nameserver 4.2.2.1
nameserver 4.2.2.2
nameserver 4.2.2.3
option rotate
option timeout:1
(With a good dns server lol !)