Why your IP can change
Residential connections, mobile networks, VPNs and some business connections can change public IP address. If a firewall allowlist stops working, confirm the current public address before assuming DNS has broken.
$curl dnsnow.co.uk/ip4
What is my IP4?
This page shows the public IP address seen by the DNSNow web server. If you are behind a proxy, VPN, CDN or corporate network, this may not be the address of your device.
Reverse DNS and PTR records
Reverse DNS maps an IP address back to a hostname using PTR records. It is often managed by the IP address provider, not the domain DNS provider.
Learn record types →