How to block a IP address in WordPress site

I can see a few recent activities in my WordPress where some users are keep on trying to login on the admin id of the website. And I had changed that but it looks to be continued. My site looks to be working a bit slow. I am trying to find out some way through which I can simply block this thing and does not allow anyone to login to the admin section of the site. And I am quiet sure that there will be a way of doing the same. Like a way through which if sometime tries to login it must get blocked on its own.

You can do this through a plugin. I do not think there is some kind of autoplugin for the same. You can try using a good anti-spam plugin which take care about the problem. And if you go with the paid edition then you will simply get lot more better options. There are ample of them to try out. You can start with WP-SpamShield Anti-Spam. This one is a free edition and has many features which are wroth testing. Just download and test this out and see what output you are getting.

When you are done with making your WordPress site you have to start working on the security part. There are few set of points that you have to take care. Like making your site more and more secure. There are many articles on the web which will tell you how you can do the same. And for the spam thing, it can be controlled through various third party plugin. Among all the most popular one is Akismet. You have to get a license of this to use its all features. It is effective and it will secure your website.