Autonomous System Numbers (last updated 2008-04-07) Registries included below: - 16-bit Autonomous System Numbers - 32-bit Autonomous System Numbers Note: The Autonomous System (AS) numbers are used by various routing protocols. AS numbers are allocated to the regional registries by the IANA. AfriNIC APNIC ARIN LACNIC RIPE-NCC AS Numbers can be obtained from the registry in your region. Listed below are the allocated blocks to the regional registries. Registry Name: 16-bit Autonomous System Numbers Reference: [RFC1930] Registration Procedures: RIR request to the IANA Registry: 16-bit Autonomous System Numbers Number Description Whois Reference Registration Date ------------ ----------------------------------- -------- ---------- ----------------- 0 Reserved - May be use to identify non-routed networks 1-1876 Allocated by ARIN whois.arin.net 1877-1901 Allocated by RIPE NCC whois.ripe.net 1902-2042 Allocated by ARIN whois.arin.net 2043 Allocated by RIPE NCC whois.ripe.net 2044-2046 Allocated by ARIN whois.arin.net 2047 Allocated by RIPE NCC whois.ripe.net 2048-2106 Allocated by ARIN whois.arin.net 2107-2136 Allocated by RIPE NCC whois.ripe.net 2137-2584 Allocated by ARIN whois.arin.net 2585-2614 Allocated by RIPE NCC whois.ripe.net 2615-2772 Allocated by ARIN whois.arin.net 2773-2822 Allocated by RIPE NCC whois.ripe.net 2823-2829 Allocated by ARIN whois.arin.net 2830-2879 Allocated by RIPE NCC whois.ripe.net 2880-3153 Allocated by ARIN whois.arin.net 3154-3353 Allocated by RIPE NCC whois.ripe.net 3354-4607 Allocated by ARIN whois.arin.net 4608-4864 Allocated by APNIC whois.apnic.net 4865-5376 Allocated by ARIN whois.arin.net 5377-5631 Allocated by RIPE NCC whois.ripe.net 5632-6655 Allocated by ARIN whois.arin.net 6656-6911 Allocated by RIPE NCC whois.ripe.net 6912-7466 Allocated by ARIN whois.arin.net 7467-7722 Allocated by APNIC whois.apnic.net 7723-8191 Allocated by ARIN whois.arin.net 8192-9215 Allocated by RIPE NCC whois.ripe.net 9216-10239 Allocated by APNIC whois.apnic.net 10240-11263 Allocated by ARIN whois.arin.net 11264-12287 Allocated by ARIN whois.arin.net 12288-13311 Allocated by RIPE NCC whois.ripe.net 13312-14335 Allocated by ARIN whois.arin.net 14336-15359 Allocated by ARIN whois.arin.net 15360-16383 Allocated by RIPE NCC whois.ripe.net 16384-17407 Allocated by ARIN whois.arin.net 17408-18431 Allocated by APNIC whois.apnic.net 18432-19455 Allocated by ARIN whois.arin.net 19456-20479 Allocated by ARIN whois.arin.net 20480-21503 Allocated by RIPE NCC whois.ripe.net 21504-22527 Allocated by ARIN whois.arin.net 22528-23455 Allocated by ARIN whois.arin.net 23456 AS_TRANS [RFC4893] 23457-23551 Allocated by ARIN whois.arin.net 23552-24575 Allocated by APNIC whois.apnic.net 24576-25599 Allocated by RIPE NCC whois.ripe.net 25600-26623 Allocated by ARIN whois.arin.net 2002-03 26624-27647 Allocated by ARIN whois.arin.net 2002-09 27648-28671 Allocated by LACNIC whois.lacnic.net 2002-11 28672-29695 Allocated by RIPE NCC whois.ripe.net 2002-12 29696-30719 Allocated by ARIN whois.arin.net 2003-03 30720-31743 Allocated by RIPE NCC whois.ripe.net 2003-09 31744-32767 Allocated by ARIN whois.arin.net 2003-11 32768-33791 Allocated by ARIN whois.arin.net 2004-05 33792-34815 Allocated by RIPE NCC whois.ripe.net 2004-06 34816-35839 Allocated by RIPE NCC whois.ripe.net 2005-02 35840-36863 Allocated by ARIN whois.arin.net 2005-02 36864-37887 Allocated by AfriNIC whois.afrinic.net 2005-04 37888-38911 Allocated by APNIC whois.apnic.net 2005-06 38912-39935 Allocated by RIPE NCC whois.ripe.net 2005-09 39936-40959 Allocated by ARIN whois.arin.net 2006-03-29 40960-41983 Allocated by RIPE NCC whois.ripe.net 2006-04-13 41984-43007 Allocated by RIPE NCC whois.ripe.net 2006-11-17 43008-44031 Allocated by RIPE NCC whois.ripe.net 2007-04-23 44032-45055 Allocated by RIPE NCC whois.ripe.net 2007-09-14 45056-46079 Allocated by APNIC whois.apnic.net 2007-10-11 46080-47103 Allocated by ARIN whois.arin.net 2008-03-27 47104-48127 Allocated by RIPE NCC whois.ripe.net 2008-04-07 48128-54271 Unallocated 54272-64511 Reserved by the IANA 64512-65534 Designated for private use (Allocated to the IANA) 65535 Reserved Registry Name: 32-bit Autonomous System Numbers Reference: [RFC4893] Registration Procedures: RIR request to the IANA Registry: 32-bit Autonomous System Numbers Number Description Whois Reference Registration Date --------------------- ----------------------------------- -------- ---------- ----------------- 0.0-0.65535 See Sub-registry 16-bit AS numbers [RFC1930] 1.0-1.65535 Reserved 2.0-2.1023 Allocated by APNIC whois.apnic.net 2006-11-29 2.1024-2.65535 Unallocated 3.0-3.1023 Allocated by RIPE NCC whois.ripe.net 2006-11-29 3.1024-3.65535 Unallocated 4.0-4.1023 Allocated by LACNIC whois.lacnic.net 2006-11-29 4.1024-4.65535 Unallocated 5.0-5.1023 Allocated by AfriNIC whois.afrinic.net 2006-11-29 5.1024-5.65535 Unallocated 6.0-6.1023 Allocated by ARIN whois.arin.net 2006-11-30 6.1024-65535.65534 Unallocated 65535.65535 Reserved References ---------- [RFC1930] J. Hawkinson and T. Bates, "Guidelines for creation, selection, and registration of an Autonomous System (AS)", RFC 1930, March 1996. [RFC4893] Q. Vohra, E. Chen, "BGP Support for Four-octet AS Number Space", RFC 4893, May 2007. []