Convert Autonomous System number (ASN) format

This tool converts Autonomous System numbers from decimal to dot notation and vice versa.

The "asplain" format was accepted by the IETF in December 2008 as the standard way to represent four-byte AS numbers. APNIC will be implementing this new format in the APNIC Whois Database and in its statistics files early in the first quarter 2009. In the meantime, please use this tool to convert between the "asdot" notation used by the RIRs since 1 January 2007 and the new "asplain" format adopted by the IETF.

For more information on "asplain", see: