Verifying Googlebot

You can verify if a web crawler accessing your server really is Googlebot (or another Google user-agent). This is useful if you're concerned that spammers or other troublemakers are accessing your site while claiming to be Googlebot. Google doesn't post a public list of IP addresses for webmasters to whitelist. This is because these IP address ranges can change, causing problems for any webmasters who have hard-coded them, so you must run a DNS lookup as described next.

To verify Googlebot as the caller:

  1. Run a reverse DNS lookup on the accessing IP address from your logs, using the host command.
  2. Verify that the domain name is in either googlebot.com or google.com.
  3. Run a forward DNS lookup on the domain name retrieved in step 1 using the host command on the retrieved domain name. Verify that it is the same as the original accessing IP address from your logs.

Example 1:

> host 66.249.66.1
1.66.249.66.in-addr.arpa domain name pointer crawl-66-249-66-1.googlebot.com.

> host crawl-66-249-66-1.googlebot.com
crawl-66-249-66-1.googlebot.com has address 66.249.66.1

 

Example 2:

> host 66.249.90.77
77.90.249.66.in-addr.arpa domain name pointer rate-limited-proxy-66-249-90-77.google.com.

> host rate-limited-proxy-66-249-90-77.google.com
rate-limited-proxy-66-249-90-77.google.com has address 66.249.90.77

 

Was this article helpful?