Dig and DNS

DNS is basically responsible for translating domain names to actuall IP addresses so that your computer can send your requests to the right server in the network.

Reverse DNS lookup

• in-addr.arpa is the domain used for reverse IPv4 lookup
• op6.arpa is for reverse IPv6 lookup

Here the IP in question is added as a subdomain in front of the ones in the list above. The DNS info is given in the response.

Reverse DNS lookup - Wikipedia

DNS lookup tool - dig

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# dig @server type name
# server: DNS-server to use
# name:   name or empty name (.)
# type:   ns, a, mx, ptr, cname, etc.

dig @8.8.8.8 a notes.noerve.com

host can be used as an alternative albeit much simpler tool

Reverse DNS lookup

Use -x in dig to resolve IPs to DNS records

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dig -x 139.162.146.84

Formatting options

• +noall + answer
• +short