البحث العكسي عن DNS

Reverse DNS maps an IP address back to a hostname using a PTR (pointer) record — the inverse of the A/AAAA record that maps a hostname to an IP. A PTR record is set by whoever controls the IP block (the hosting provider or ISP), not the domain owner, so it often reveals infrastructure rather than a public-facing site name.

Why it matters

Mail deliverability

Most receiving mail servers check that a sending IP has a PTR record that resolves back to a hostname in a matching domain (forward-confirmed rDNS). Missing or mismatched PTR records are a common reason legitimate mail lands in spam.

Security investigation

A PTR record often names the hosting provider or cloud region directly (e.g. ec2-…amazonaws.com), a fast way to tell hosting infrastructure apart from a residential or business connection.

Log enrichment

Adding a resolved hostname to access logs or SIEM events gives an analyst more context than a bare IP, especially for infrastructure that rotates addresses but keeps a stable naming convention.