host
The host command performs DNS lookups. Give it a domain name and you’ll see the associated IP address. Give it an IP address and you’ll see the associated domain name.
host howtogeek.com
host 208.43.115.82
The host is a simple and essential command line tool. It is used for the following purposes:
- Performing DNS name lookups.
- Finding the IP address of a host or vice versa.
- List and validate various types of DNS resource records such as as NS and MX names.
- Verify ISP dns server and Internet connectivity.
- Verify spam and blacklisting records.
- Verifying and troubleshooting dns server problems.
Purpose
Use host command to resolve a host name into an Internet Protocol (IP) address or an IP address into a host name.
Syntax
The basic syntax:
host ip-address-here
host host-name-here
host host-name-here [DNS-Server-Name-Here]
host [options] IPAddress | Hostname [DNS-Server-Name-Here]
List of DNS record types
Before you use the host command you should aware of common types of resource records of the DNS. Here are most common resource records:
| Type | Purpose | Examples |
| A | IPv4 IP address | 192.168.1.5 or 75.126.153.206 |
| AAAA | IPv6 IP address | 2607:f0d0:1002:51::4 |
| CNAME | Canonical name record (Alias) | s0.cyberciti.org is an alias for d2m4hyssawyie7.cloudfront.net |
| MX | Email server host names | smtp.cyberciti.biz or mx1.nixcraft.com |
| NS | Name (DNS) server names | ns1.cyberciti.biz or ns-243.awsdns-30.com |
| PTR | Pointer to a canonical name. Mostly used for implementing reverse DNS lookups |
82.236.125.74.in-addr.arpa |
| SOA | Authoritative information about a DNS zone | see below |
| TXT | Text record | see below |
By default, host command looks for A, AAAA, and MX records only.
Host command examples
Let us see how to use host command on Linux and Unix. You need to give a hostname or an IP address as an argument to get various information about that host. Open the Terminal applications and type the following commands.
Find the IP address of a Hostname
To find the address of a host machine called wks05, run:
host wks05 |