Penguin didn’t just hit anchor texts or relevance. It nailed similar IP addresses. For years, we didn’t care and had nearly a hundred sites clustered all on one C-class IP range that drove rankings and traffic. It didn’t hurt us until Penguin.
We don’t talk about it in the Penguin section because you have to be a power-player to really be hit by this. This is an advanced topic, so we’re keeping it in the advanced section.
Host clustering has two aspects:
- The SERP itself
- Link power
We kept noticing sites would “flip” in and out with other sites competing with each other. After April, we were unsuccessful in ranking multiple sites on the same IP range in a competitive SERP. Only one at a time would rank, and they would “flip” with each other depending on which one was the most powerful.
All things being equal, we could move hosting on feeders to new IP ranges and increase rankings.
The Term Itself
We called it “IP crowding” for years until Matt Cutts had this video:
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So now, we call it host clustering.
Symptoms
We can’t really talk about symptoms much because they match Penguin entirely (we think it is wrapped into Penguin). Only power spammers would be penalized.
If you notice yourself flipping in and out of a particular SERP, the easy solution we would normally give is “build more links” so you overpower the other site. However, if you’re in a highly competitive niche – you might not be able to overpower the competitor so easily. Ranking might only need to last for a few days to have a big payday. In this case, continue reading.
Tests & Diagnosis
Move the host.
Get on a completely different A or B class. It’s not that hard to find one. C and D class will not get you passed the filter.
Complications
Cloudflare works to bypass this issue, but it’s a popular service now so there is a good chance another site in the top 10 will have CloudFlare. You’re back in the same situation.
Solution
If the test worked, the solution is done.