A collection of simple, powerful network utilities designed to help you diagnose and verify your internet connectivity, email configuration, and domain settings.
Email Authentication Checker
Verify and analyze a domain's SPF, DKIM and DMARC configuration, and test changes to an SPF record before publishing it.
spf.access.nu
Email Provider Checker
Check a domain's mail configuration and mail provider.
mx.access.nu
IP Address Information Checker
A clean interface for getting information about an IP address, which also supports checking a domain name to see info about the IP address/addresses it points to.
ipinfo.access.nu
Very Simple IP Address Checker
Quickly determine your public IP address without any unnecessary clutter.
Also available for use from the command line:
$ curl ip.access.nu
ip.access.nu
Very Simple IPv6 Address Checker
Check your public IPv6 address and verify your IPv6 connectivity.
Also available for use from the command line:
$ curl ip6.access.nu
ip6.access.nu