Published: April 22, 2014
Within off-page SEO activities, the link building techniques have gotten more and more sophisticated during recent years.
Ideally, external backlinks should be from as many different IP addresses as possible.
But there is a thing called "C block"...
Let's see more about what this is and how you should optimize according to it!
When building links, acquiring them from merely unique IPs isn't enough.
Below you'll find more information about c-blocks and why they are vital in healthy link building.
Here's an example for an IP address:
(Please note that the IP above is purely for the sake of an example and it has no other significance/importance whatsoever)
The entire series side-by-side represents a full IP address.
The c clock (or cblock) is actually the 133 in it.
The structure of an IP address is the following:
From left to right, there is the a-block, b-clock, c-block, d-block.
Ideally, it's desirable to have as many backlinks from as many unique IP addresses as possible, but the c-clock shouldn't be disregarded either.
Let's view the same example of an IP address again:
These below are considered "different IP addresses" - as most SEO-ers would agree:
18.104.22.168 22.214.171.124 126.96.36.199 188.8.131.52
They are different among each other, because they're not identical.
Thing is, their c-blocks are the same: 133.
What's adequate in off-line SEO is to have different c-blocks as well.
184.108.40.206 220.127.116.11 18.104.22.168 22.214.171.124
The above example illustrates IP's that are although different, they also have different c-blocks.
In link building, having backlinks merely from unique IP addresses isn't enough. C-blocks distinguish the sources inbound external links even more.