Second phase of four-byte AS number assignment policy begins 1 January 2009

Phase two of the four-byte AS number assignment policy begins 1 January 2009

From 1 January 2009, APNIC will assign four-byte AS (AutonomousSystem) numbers by default when receiving requests for AS numbers.Two-byte AS numbers will continue to be assigned when specificallyrequested.

This change marks the second phase of theglobally coordinated transition to four-byte AS numbers. For moreinformation on the implementation phases of the four-byte AS numberpolicy, please see "Policies for Autonomous System number management inthe Asia Pacific region" section 6.3, Timetable for moving from two-byte only AS numbers to four-byte AS numbers.

Information on four-byte AS numbers

To learn more about how the transition to four-byte AS numbers may affect your network, see:

The"asplain" format was recently accepted by the IETF as the standard wayto represent four-byte AS numbers. APNIC will be implementing this newformat early in the first quarter 2009. For more information on"asplain", see:

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