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Look up the reverse DNS (PTR) of an IP address

harmlessDNSdebian, ubuntu
Adjust the values, the command updates live
user@server
dig +short -x 203.0.113.10

Prints the hostname that the PTR record of an IPv4 or IPv6 address points to. Mail servers without a matching reverse DNS entry are rejected or marked as spam by many recipients. The PTR record is not set by the domain owner but by the operator of the IP network, usually in the hosting provider’s customer portal.

Also searched as

  • check reverse dns
  • ptr record of server ip
  • which hostname belongs to an ip

Related one-liners

All in DNS

Verify reverse DNS of a mail server IP (FCrDNS)

$ptr=$(dig +short -x 203.0.113.10 | head -n 1); echo "PTR: $ptr"; dig +short "$ptr" A
harmlessDNS

Check a domain's DKIM key in DNS

$dig +short default._domainkey.example.com TXT
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Look up the MX records of a domain

$dig +short example.com MX
harmlessDNS

Show the DMARC policy of a domain

$dig +short _dmarc.example.com TXT
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Show the SPF record of a domain

$dig +short example.com TXT | grep -i "v=spf1"
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Check DNS propagation across public resolvers

$for ns in 1.1.1.1 8.8.8.8 9.9.9.9 208.67.222.222; do echo "$ns: $(dig +short @$ns example.com A | tr '\n' ' ')"; done
harmlessDNS

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