host command – nixCraft

Linux / Unix: Dig Command Find Out TTL (Time to Live) Value For DNS Records

May 5, 2013June 9, 2017in BASH Shell, CentOS, Debian / Ubuntu, FreeBSD, Linux, RedHat and Friends, Suse, UNIX last updated June 9, 2017

I would like to see the Time-to-live (TTL) value for a ‘AAAA’ and A record for domains. How do I see Time-to-live (TTL) for a DNS record under Unix or Linux operating systems using command line options?

How To Look Up DNS on a Linux and Unix Systems

January 12, 2013January 12, 2015in BASH Shell, CentOS, Debian / Ubuntu, FreeBSD, Linux, UNIX last updated January 12, 2015

How do I look up for DNS (Domain Name System) information on a Linux or Unix-like systems using command line options?

HowTo: Find Out DNS Server IP Address Used By My Router?

April 24, 2012August 31, 2013in Linux, Networking, UNIX, Windows last updated August 31, 2013

My router configured by ISP tech and it is set to get DNS server address automatically from upstream. Is there is a way to find out the IP address of the dns server used by my router which is located at 192.168.1.1? Is there Linux, Unix, Apple OS X, or MS-Windows command that I can use get the same information?

Linux and Unix host Command Examples

January 12, 2012May 16, 2017in Commands, Linux, UNIX last updated May 16, 2017

I am a new Linux and command line user. How do I use host command line utility to verify DNS settings on Linux and Unix-like operating systems? How do I use dig command to find the IP address of a host name or host Name of an IP address?

Linux / Unix: Look Up IP Addresses

April 13, 2011April 13, 2011in Linux, UNIX last updated April 13, 2011

How can I look up IP addresses under UNIX or Linux operating systems using command line options?

Linux / UNIX: DNS Lookup Command

November 8, 2010January 14, 2014in Commands, Linux, UNIX last updated January 14, 2014

How do I perform dns lookup under Linux or UNIX or Apple OS X operating systems without using 3rd party web sites for troubleshooting DNS usage?

Google Apps Domain Create SPF Records For BIND or Djbdns

October 19, 2010October 22, 2010in Bind dns, UNIX last updated October 22, 2010

I work for a small business and outsourced our email hosting to Google. However, I noticed that spammers are using our From: First Last to send their spam messages. All bounced messages come to our catch only account. How do I stop this? How do I validate our domain using SPF? How do I configure a SPF for Google Apps domain using BIND 9 or djbdns?