[olug] list of United States IP blocks

Christopher Cashell topher-olug at zyp.org
Thu Jan 11 11:14:26 CST 2018

On Thu, Jan 11, 2018 at 10:09 AM, Lou Duchez <lou at paprikash.com> wrote:

> I found a list of IP blocks assigned to the United States:
> http://www.ipdeny.com/ipblocks/data/aggregated/us-aggregated.zone
> Anyone finding that they're NOT on this list?  I find that my various IPs
> are all on here.  There's all sorts of firewally goodness I can use this
> list for, assuming it's reliable.  (Assuming they're telling the truth,
> they update their list on a daily basis.)

There are lots of pretty good GeoIP databases, but be aware that none of
them are going to be perfect, and IP assignment and route advertisements
change regularly.  They can be very useful, but if you rely on them, or
expect them to be correct, or make decisions such as traffic blocking based
on them, you may run into trouble.  At the least, I would recommend not
taking hard action beyond very specific subnets that are well known to be
assigned to certain countries.

It wasn't that long ago that I saw a chunk of public IP space at work that
Google believed was from the Philippines.  Accessing Google through that
block caused us to get redirected to http://www.google.com.ph, even though
the actual Internet connection point was in Denver.  And Google does a
better job than most at maintaining GeoIP information.


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