The contents of this legacy page are no longer maintained nor supported, and are made available only for historical purposes.
NOTE: NetGeo has not been actively maintained since 1999, and this will probably not change in the foreseeable future. As a result, there are several known major issues affecting accuracy and service availability. Please be warned that NetGeo may give wildly incorrect results, especially for recently allocated or re-assigned IP addresses.
Also, domain-name lookups are no longer supported.
Please see a list of NetGeo alternatives.
While it is expected that most users of the NetGeo service will access it via programming APIs. The CGI interface is documented here, however we do hope you'll find the programming APIs a better interface than talking directly to the server.
The server rate-limits access to 30 lookups in 30 seconds from a given source IP address. The server does not use a rolling average. If more than 30 seconds have elapsed since the last query time, then 30 lookup credits are given and the query time is set to the current time. Otherwise while credits remain each additional lookup subtracts a credit. Once all credits are exhausted, any additional lookup attempts fail and the query time is set to the current time. An important result of this algorithm is that if too many lookups are performed in an interval, the time until new lookups can be requested is measured from the most recent request. This means that once the limit is exceeded, you must wait at least 30 seconds before trying again, otherwise you can be locked out indefinitely. Since the limit is enforced at IP address granularity, it is suggested that on machines with multiple NetGeo users that an exponential backoff with a random shift be used when the time limit is exceeded.
Currently array lookups of N items are being counted as [(N-1)/10 + 1] individual lookups, to encourage usage of the array lookup APIs.
Educational or Research Institution Use of CAIDA NetGeo Server
NetGeo has been licensed to Ixia, a commercial entity who markets a
geographic location product called IxMapping.
(See Ixia's IxMapping).
Ixia's IxMapping services is designed to assist Internet
content providers, e-commerce firms, ISPs, and others to track the
geographic location of Internet users, destination servers, and
If you are from an educational or research institution and have
need for different access policies to CAIDA's NetGeo server
, please email netgeo-info @ caida.org to discuss
overriding the rate-limit.
We would like people using NetGeo in research projects
to provide the following information, which helps us both in
making NSF aware of the utility of the project to the community,
as well as planning future enhancements to the NetGeo service:
basic description of the project, including,
if possible, duration, how it is funded and
what deliverables are related to NetGeo
whether you're interested in lat-long information
or name-based information (basically, what kind
of queries are of greatest interest to you)
how many queries per interval (minute, day, week) you need
if you are trying to process/analyze things in real-time
or from traces/logfiles, for which array (batch) lookups
may be viable/preferable
notifications of any reports/publications
you have that use NetGeo data
if you're interested in potential collaborations with
CAIDA on Internet mapping related projects
interested in getting additional information on this product should
All policies for access to CAIDA's NetGeo server may be changed at any time for any reason. The service may not always be available. No warranty or guarantee is made with respect to the availability of the service or to the accuracy and fitness of returned results.