An IP address is your address on the internet and is used to route all traffic between your computer and the websites and other internet services that you use. When you use WordPress.com we record your IP address, whether you are adding a post, a comment, or just reading an article.
Blocking IP Addresses
On occasion, we are asked if an IP address can be blocked. This may be, for example, if someone is posting unpleasant comments and/or is generally being annoying to you or other bloggers. Please note that we do not block IP addresses for the reason that it may inadvertently prevent other people from using WordPress.com.
However, you can choose to blacklist an individual’s IP address from Settings -> Discussion in your blog’s dashboard. This will send all comments from that individual directly into your spam queue.