Please verify RFC1918 filters

Tue Mar 22 22:52:27 UTC 2005

We here at AOL have noticed that there are still some people filtering
172.0.0.0/8, which is causing AOL subscribers to get blocked from some
sites.  As a matter of general IP route filtering hygene I thought it
worth mentioning (again) to see if we can get this tamped down (or, better
still, stamped out).

For reference, RFC1918 20 bit block space is
172.16.0.0      -   172.31.255.255  (172.16/12 prefix)

ARIN-assigned AOL block ranges that have 172 in the first octet are:

172.128.0.0/10
172.192.0.0/12
172.208.0.0/14

Please double check your filters to make sure you are not accidently
blocking AOL in the non-RFC1918 space.  It would be useful to pass this
along to your downstreams as well.  AOL is also working directly with
the companies who have misconfigured firewalls where we notice problems
with filters.

/vijay