Hello- ARIN received the IPv4 address blocks 23.0.0.0/8 and 100.0.0.0/8 from the IANA on November 30, 2010. We will begin making allocations of /22 and shorter prefixes from these blocks in the near future in accordance with ARIN’s minimum allocation policy. Network operators may wish to adjust any filters in place accordingly. For informational purposes, a list of ARIN's currently administered IP address blocks can be found at: https://www.arin.net/knowledge/ip_blocks.html Regards, Leslie Nobile Director, Registration Services American Registry for Internet Numbers (ARIN)