[arin-announce] ARIN to Issue 4-byte ASNs by Default Starting on 1 January 2009

Member Services info at arin.net
Tue Dec 30 08:15:19 EST 2008

Beginning on 1 January 2009, ARIN will be assigning four-byte Autonomous 
System Numbers (ASNs) by default, unless a 2-byte ASN is specifically 
requested. Following a globally coordinated policy, ARIN and all the 
Regional Internet Registries began allocating four-byte ASNs by request 
in January 2007; January 2009 marks the transition to allocating 
four-byte ASNs by default (see http://www.arin.net/policy/nrpm.html#five1).

Because this is a relatively new implementation, it is possible that 
some devices may not be able to recognize the new 4-byte ASNs. ARIN 
urges operators to verify that their routers and those of any transit 
providers or peers are ready and able to accept 4-byte ASNs.

Additional information about four-byte ASNs or how to request them can 
be found at:


Please contact hostmaster at arin.net if you have any questions concerning 
the ASN policy and four-byte ASNs.

Leslie Nobile
Director, Registration Services
American Registry for Internet Numbers (ARIN)

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