Does disavowing a subdomain work? Will disavowing a domain include all the subdomains?

Question

I currently disavow the domain example.com using Google's disavow links tool.

What can I do if I want do disavow a subdomain? i.e. spam.site.com. I'm also assuming that if I were to disavow the domain it would include all subdomains?

Answer 1

After receiving clarification on this from John Mueller at Google, disavowing a root domain will also disavow all other sub domains under it.

For example, disavowing:-

domain:example.com

Will also disavow:-

sub23.example.com
sub4646.example.com
www.example.com

You can of course, disavow individual sub domains like domain:sub23.example.com though which will only affect that individual sub domain.

Here is a link to the old answer from the revision history

Answer 2

In addition to Geoff's answer:

When you talk about disavow, are you talking about Google's Webmaster Tools disavow links tool? If so, then this isn't the correct way to go about it; I will explain at the end.

Firstly all domains, for example: example.com, is a website with the Top-Level Domain being .com.

So in a simple way example.com is a subdomain of .com, obviously entering .com doesn't bring anything up, however the subdomain example.com will bring up the website as it is a separate entity.

Now expanding this, http://example.com and http://www.example.com these are both to completely separate websites. www and non-www websites both redirect (normally if set up correctly) to the same server and resolve as the DNS setting normally has 2 A records pointing to the domain name - one for non-www traffic and one for www traffic.

Now thinking about this I'm sure you can now understand that subdomain.example.com acts in the same way that www does as this is also a subdomain of example.com.

Now with regards to disavowing links, if you mean Google Webmaster Tools disavow links, this option should only be used after all necessary manual removal of the links has been made as this will show Google that you have taken the time and effort to amend whatever it is that you are doing (this is more in the case where you have been penalized by Google for unnatural links, etc...).

So in summary:

• .com is a top-level domain (TDL).

• example.com is (basically) a subdomain of .com, however this is your domain name.

• www.example.com is a subdomain of example.com, but is often redirected back to the same place as example.com. This can be used for anything you want, but remember it is completely different.

• Disavow each sub-domain individually, as diavowing example.com will not disavow a.example.com