Zone file database records divide DNS information into three primary types: NS (Name Server) records, MX (Mail Exchange) records, and A (Address) records. NS records indicate the name servers. MX records indicate the hosts that handle email delivery; the priority (pri) number indicates the order in which mail servers are used, with the lowest number receiving the highest priority. The A (Address) records map hostnames to IP addresses, the real names of machines.
nslookup
========
The nslookup program allows the user to query Internet domain name servers interactively or non-interactively
# nslookup www.redhat.com
Server: 128.121.247.232
Address: 128.121.247.232#53
Non-authoritative answer:
Name: www.redhat.com
Address: 209.132.177.50
dig
===
Use the dig command to determine whether the name server for your domain is configured correctly.
You can quickly determine the Name servers of your host or any other host:
# dig ns your-host.com
Check your (or another) website against the host's name servers:
# dig www.your-domain-name.com @ns.your-host.com
Dig can provide output that is in the same format as the zone file itself. Here is how to get the whole zone file:
# dig any your-domain-name.com
Here are the most useful dig query types: dig any (gathers all DNS information), dig ns (gathers name server information), dig mx (gathers mail exchanger information) and dig a (gathers network address information).
Reverse DNS from command line. Quick and easy way to look up a domain name given an IP address.
# dig -x 192.168.52.2
host
====
This is the simplest of the DNS commands. It is a quick way to determine the IP address of a hostname.
The host command accepts arguments that are either the fully qualified domain name or the IP address of the server when providing results.
# host
# host www.domainname.com
To perfrom reverse lookup
# host 192.1168.52.2
To find all of the information about a host maintained by the DNS, use the command:
# host -a
# host -a redhat.com
# host www.your-domain-name.com
The -a option will return all of the DNS information in verbose format:
# host -a www.your-domain-name.com
Now that you know the IP address for www.your-domain-name.com, try a reverse lookup:
# host
To list a complete domain, use the command:
# host -l
# host -l redhat.com
dnsquery
========
The dnsquery program queries domain name servers via the resolver library calls /etc/resolv.conf.
# dnsquery
# dnsquery www.redhat.com
nslookup
========
The nslookup program allows the user to query Internet domain name servers interactively or non-interactively
# nslookup www.redhat.com
Server: 128.121.247.232
Address: 128.121.247.232#53
Non-authoritative answer:
Name: www.redhat.com
Address: 209.132.177.50
dig
===
Use the dig command to determine whether the name server for your domain is configured correctly.
You can quickly determine the Name servers of your host or any other host:
# dig ns your-host.com
Check your (or another) website against the host's name servers:
# dig www.your-domain-name.com @ns.your-host.com
Dig can provide output that is in the same format as the zone file itself. Here is how to get the whole zone file:
# dig any your-domain-name.com
Here are the most useful dig query types: dig any (gathers all DNS information), dig ns (gathers name server information), dig mx (gathers mail exchanger information) and dig a (gathers network address information).
Reverse DNS from command line. Quick and easy way to look up a domain name given an IP address.
# dig -x 192.168.52.2
host
====
This is the simplest of the DNS commands. It is a quick way to determine the IP address of a hostname.
The host command accepts arguments that are either the fully qualified domain name or the IP address of the server when providing results.
# host
# host www.domainname.com
To perfrom reverse lookup
# host 192.1168.52.2
To find all of the information about a host maintained by the DNS, use the command:
# host -a
# host -a redhat.com
# host www.your-domain-name.com
The -a option will return all of the DNS information in verbose format:
# host -a www.your-domain-name.com
Now that you know the IP address for www.your-domain-name.com, try a reverse lookup:
# host
To list a complete domain, use the command:
# host -l
# host -l redhat.com
dnsquery
========
The dnsquery program queries domain name servers via the resolver library calls /etc/resolv.conf.
# dnsquery
# dnsquery www.redhat.com
