From 1 July 2009, APNIC will assign four-byte AS numbers by default when receiving requests for AS numbers. Two-byte AS numbers will only be assigned if the applicant can demonstrate that a four-byte only AS number is unsuitable.
This change marks the next phase of the transition to four-byte AS numbers.
The final phase of the transition begins 1 January 2010, when APNIC will cease to make any distinction between two-byte only AS numbers and four-byte only AS numbers, and will operate AS number assignments from an undifferentiated four-byte AS number pool.
For more information on the implementation phases of the four-byte AS number policy, please see section 6.3 of:
Policies for Autonomous System number management in the Asia Pacific region http://www.apnic.net/asn-policy
Information on four-byte AS numbers -----------------------------------
To learn more about how the transition to four-byte AS numbers may affect your network, see: