Whois Usage Restrictions

The information in this article very important for any one who uses software that performs whois lookups. Please make sure that you understand this fully.

All domain name lookup software including Domain Name Analyzer, Domain Punch pro, Watch My Domains (Pro & ISP), etc. require access to port 43.

You will need to enable access to this port if you are behind a firewall or proxy. So ensure that the whois lookup problem is not because of a blocked port 43 before reading further.

Whois Usage Restrictions

Software like Watch My Domains (Pro and ISP) and Domain Name Analyzer retrieves domain records by connecting to various whois servers. These whois servers are operated by the registry and/or various domain registrars.  

Because of the large number of Whois lookups that are being done most registrars have set limits on how the whois servers could be accessed.  It is very important that these terms and conditions are understood and followed whenever you use a software that performs whois lookups.

Unfortunately there is no uniform set of rules followed by each registrar. Each and every registrar has their own set of rules (and some times these are not even mentioned anywhere) 

Problems with too many unrestricted lookups

If you do too many whois lookups you will soon start seeing outputs similar to the following

Welcome to the NSI Registrar Whois Server.

Your IP address is contained within a list of IP addresses that may have failed to abide by Network Solutions' Whois policy.

If you feel this is in error, please contact us at ....

Here are some examples of the limits set by different domain registrars. Please note that these are just a few examples. Almost all registrars have similar limits in place.

Tucows (whois.opensrs.net) rejects multiple simultaneous connections from the same IP. You will have to be satisfied with one connection at a time.

BulkRegister (whois.bulkregiter.net) will immediately block the IP temporarily if they notice a large number of connections being made. This is done by their software automatically.

Network Solutions (whois.networksolutions.com) will block the IP temporarily if you do more than 1000 lookups in a day.

Go Daddy (whois.godaddy.com) will simply start hiding all the relevant information from the returned whois text if your IP gets in their list.

Nominet (UK domains) has a new whois usage policy applicable from March 31 2003.

...most other registrars also have similar restrictions.

Doing Whois Lookups, the right way

All our products like Watch My Domains, Domain Name Analyzer, etc. allow you to configure the number of simultaneous connections and a connection interval. This will ensure that you don't abuse the whois servers and get banned. The ideal setting in software like Watch My Domains is 1 connection and a lookup interval of 12 seconds or more (5 connections per minute).

If you find your IP address being banned permanently, the only solution is to contact the registrar and discuss the problem with them.

If your internet connection has a permanent IP, you should be very careful while using any software that connects to whois servers. Make sure that your IP doesn't find its way into the registrar ban lists because of excessive usage. If you ever find your IP banned give them a call and explain your situation. Find out what got you banned and assure them that you will follow their whois policy usage guidelines.