SEO Hosting

August 12, 2015
Rocket IPs

*this is a translation of the original text that can be found on

As most people probably know, hosters offering web page and domain maintenance services have different IP address ranges on offer. The simplest variant is to buy cheaper, existing accounts on a shared server to build a PBN. Usually, these accounts have certain limit of domains that can be assigned to them. Each domain that is located on a shared account will have the same IP address. This will also apply to all other accounts created on on that server and sold to others whose websites are hosted by the same hoster. In normal cases, the servers managing shared accounts have Hundreds of domains assigned to the same IP address.

In some more extreme cases, tens of thousands of gTLD or ccTLD (generic or country code Top Level Domain) domains can be on one shared hosting, all of which are assigned the same IP address. A good example of such an overloaded address is, which has almost a thousand TLD domains. Hypothetically, getting links from all of these domains would mean all of them wold have the same IP address, which would look pretty suspicious, to put it mildly. And yes, in such an extreme case, the probability that that the links would be from the same owners would be very small, meaning these links would be would be very good quality, if all you’re taking into account is their source. Here, I’m not taking into account the link environment and the kind of content it’s located in.

Another case that is more popular among companies offering SEO services is having a VSP or dedicated server. A VPS server is a virtual piece of a larger server, where the user has more resources at his or her disposal. Among the many VPS server offers, there are also those that allow us more than one IP address—however, these are almost always in the same C class (for the sake of simplicity, I will allow myself to completely omit classless routing). It is standard for one VPS machine to be assigned one IP address. Publishing our PBNs on a VPS server, we have on average from 1 to 4 IP addresses at our disposal, all of which are likely to to be in the same C class. The overall amount of domains from these addresses depends solely on the owner of the server. Hypothetically, putting links on all of the domains installed on a VPS server, we get from 1 to 4 IP addresses.

Notice, however, that the origin of the domains will be less diverse. All of the domains will probably belong to one owner, with the possibility of defining DNS servers being largely dependent on where the domain is registered. Therefore, a PBN created in this way will look less natural, despite it being spread around a few IP addresses. The same thing will happen when we use a dedicated server. Then, we can also be sure that the IP addresses we used will not be used by anyone else besides us. Contrary to what you may expect, this solution makes out PBN look even more unnatural.

The third solution that was supposed to be a cure for all of the aforementioned afflictions are SEO hostings that offer many IP addresses assigned to one account. The addresses are usually offered in packages and are located in different C classes. The efficiency of such an account is very limited, as the owner of the hosting usually allows us access to 0.5-2% of the power of the processor/memory/IO operation/etc. Usually, all that’s available here are simple pages based on HTML or well-optimized PHP scripts. If we assume that class C is still important to us, purchasing such an account allows us access to a few classes hosting firms offer. Let’s see what kinds of offers are available in Poland:

  • SEO hosting: a maximum of 24 IP addresses from 67 different C classes on one account
  • SEO hosting: a maximum of 53 IP addresses from 159 different C classes on one account
  • SEO Lite: a maximum of 36 IP addresses from 16 different C classes on one account
  • SEO hosting: a maximum of 100 IP addresses from 8 different C classes on one account
  • SEO Pro: a maximum of 27 IP addresses from 20 different C classes on one account. This package can be purchased twice.
  • SEO Premium: 100 IP addresses from 29 different C classes on one account

There are a few other hostings that offer a IP address diversification according to different C classes, but I don’t see the need to name them all here at this time. Generally, the C classes do not appear more than once, meaning the number of addresses cumulates if you purchase accounts from several different hosters. While this level of C class address diversification of may seem like a fantastic solution at first glance, there are many limitations to watch out for. The first of these is equipment efficiency. The administrators of these accounts are very sensitive when it comes to efficiency and attempts to build PBNs that will take up more resources than we are allowed, meaning our account is likely to get blocked. 503 errors are also a common, albeit less serious problem, that we should see as a sign that it’s time to optimize our scripts. Here, an IP address’ geolocation, which is is emphasized in some services, irrelevant because all of these IP addresses point to only one server, regardless of which internet provider they belong to. To see how a real Polish SEO hosting looks , we’re going to take a look at Ionic in Cracow.


Autonomous systems

Now that we have a general idea about the kinds of IP addresses available, let’s get to the most important part of this topic: the aforementioned ASes. Dominik used the example of “/” masks to show that some address pools belong to small or big hosting providers. Looking at the address:, we can tell that we have 371 internet providers to choose from in Poland. From the “closed” status by many of the company names, we know that not all of them still work. Furthermore, not all of them off the kind of hosting services that allow for pages to be published. Even on this list, we can see large corporations that use the assigned address pools for their own needs. Let’s go back to the where I started talking about the meaning of IP addresses. The entire world wide web was created by connecting smaller IP networks.

To simplify we can assume that the smallest IP network possible is one C class (no offense, networkers). Central management of the kind of global computer network the internet is impossible, not to mention inadvisable. That’s why internet governance is independent on the highest level. Those are numbered areas, each of which covers many IP networks. These areas are called autonomous systems. In accordance with the technical specifications, which in Europe are defined by RIPE, it is RIPE that manages the assignment of new autonomous systems to independent providers. An autonomous system is a network or a group of networks under collective administrative control. Of course, it also has many more tasks and functions, but those are not nearly as important from the SEO point of view.

We can check all of the statistics of all of the autonomous systems here: There are over 40 thousand autonomous systems in the world. In Poland, we currently have just over a thousand. Take a look at this fragment of the list of Polish autonomous systems.

AS6778 BPTNet-AS
AS8364 AS8364
AS8459 AS8459

Every autonomous system has to have its own number assigned to it by IANA/RIPE. This is a 32-bit number called an Autonomous System Number (ASN), which is further used by the BGP protocol when route information is exchanged. The numbers are unique so the routing doesn’t loop. As with IP numbers, we can also use private AS numbers here. These numbers are usually used in large networks. Private ASNs range from 64512 to 65535, and public ones range from 1 to 64511. One internet provider, hoster or corporation can possess more that one autonomous system. The preciseness with which these addresses are assigned on the system level is a good compromise between realism and the complexity of obtaining data for analysis. Every AS has art least one announced prefix. A announced prefix is a constant range of IP addresses assigned to one AS. An example of a announced prefix by LEASEWEB with the number AS16265, the server provider Silesia SEM is set up on, is The data concerning prefixes announced by ASes are publicly available. Therefore, the rest of the data tells us that:

ASN 16265
Number of prefixes:92
Number of IP addresses:339200
AS description:LeaseWeb B.V.


Based on the information above, we should understand at least two things just fine already: the IP address range assignment date and the prefix. Every autonomous system can announce a certain number of IP addresses that are grouped into prefixes. What exactly does that number mean? From an SEO point of view, we can get 2228 different C address classes, and there will be exactly 512 in the announced prefix. Hetzner announces 16 prefixes, that give us a total of 570,368 IP usable addresses. The ASN is also important. When it was first defined, it was written on two bytes, which means that the maximum possible number of launched ASes could have been 65,536. Luckily, the length was recently changed to four bytes, allowing many more ASes to be created. Despite this, however, the subsequent numbers assigned are still lower than 65,536. AS number also tell us if the announced prefixes belong to the same AS, despite a significant difference in the first two octets of the address. Now let’s see how this looks in reality.

This time we’re going to study the largest autonomous system in Poland: TPNET, AS5617. According to publicly available data, TPNET (Polish Telecommunications), announces only 38 prefixes despite the fact that it has over twice that amount to announce. As ever, theory and practice differ from each other, showing that RIPE’s records and lists are just administrative creations that should always be compared to what really happens. The size of an AS isn’t defined by the number of announced prefixes, but rather by the range of IPs assigned according to the broadcast masks. There are of course providers who announce many more prefixes, but the grand total of IPs is much smaller than it is in the case of TPNET. TPNET possesses almost 7 million IP addresses. Let’s see how TPNET broadcast prefix masks look.


Looks familiar, doesn’t it? It should. All of the class addresses used by TP to provide users with internet and serve websites are here. So what does that have to do with SEO hostings? A lot. If we just go back to the third address-obtaining method , SEO hostings, we have already definitely notcied that quite a few C class addresses are available in each one. These companies even tell us what addresses they mean exactly in their offers. People that use other SEO hostings can check exactly what IP addresses are available to them in Direct Admin. Looking at a few of them, we come to the shocking realization that none of the SEO hosting providers is an autonomous system. The address pools are leased from other ASes. And if they are leased, what ASes are within our reach? Unfortunately, here we must draw yet another shocking conclusion:

  • SEO hosting—1 AS
  •—3 ASes
  •—1 AS
  •—1 AS

I suppose none of you will be surprised that the AS that repeats in the abovementioned four examples is AS 16276, which is OVH from France! That’s why diversifying IPs and C class addresses is in vain—when reading public data, it turns out that all of them are in the same autonomous system.

Questions about autonomous systems

Does this really effect SEO?

Of course it does. If the data is public and I can piece together a little part of the internet and imagine who certain address class ranges belong to, then you can be sure Google had been able to do this for a long time, and definitely takes this into consideration when evaluating links. Not just links coming from different domains, mind you, but also links from IP addresses that belong to different autonomous systems.

Can a hosting company become an autonomous system?

Naturally, a bit of effort is all it takes. You can find out what kind of effort exactly by reading the text about servers and hostings in the service of SEO. In short, a new autonomous system has been created in Cracow. There are only 2 C classes in it, but the effects it produces even I difficult industries are very good.

Tools for checking ASes

What tool can I use to check my As?

An interesting plugin that allows us to check the data about the autonomous system of the site we’re currently looking at is ASnumber 1.6, which can be turned on in Firefox.

Other questions we could be asking ourselves after reading this article are:

  • How many ASes is my PBN set up on?
  • What hostings/Ipki’s should I transfer my PBN to in order to increase the number of ASes?

Marcin Szajda answered these questions in his article, a fragment of which I’m attaching below.

How can I check how many ASes our PBN has?

You have to perform the following command in unix bash:

whois -h -v IPserwisu

Let’s check the blog’s IP”


We can see that the IP belongs to autonomous system number 16275 of Leaseweb.

If we have more IP addresses to check, it will be easier to check them all at once. We have to enter them into an ips.txt file, for example, each in its own separate line, and start loop checking:


This way we can check SEO hoster offers that offer x IP addresses and find out just how scattered around the ASes the IP addresses on offer are.

If we don’t have an IP list we can also check using the domain name using the command:

whois -h -v $(dig +short)
or using the version for many domains
for ii in $(for i in $(awk '{print ($1)}' domains.txt); do dig "$i" +short; done); do whois -h -v "$ii"; done

The bash scripts above are based on the IP mapping service on ASN offered by Cymru Research.

What IP/hosting should I move my PBN to?

You should choose a hosting that allows the greatest AS dispersion. For example, SEO is proud to offer 53 different IP addresses—however, they belong to only 2 ASes: HETZNER-AS Hetzner Online AG RZ and PLUSSERVER-AS intergenia AG. This is still a better result that most Polish SEO hostings, where 1 AS is standard.

So before buying a hosting for SEO purposes, you need to check which AS the hosting company domain belongs to. There is a 99% chance that the IP of the server will belong to the same AS, and even if it doesn’t, you can usually back out of the hosting contract within 7-14 days.

Autonomous systems in Polish hosting companies. Marcin checked the hosting company domains from the AS point of view using a site called Web Hosting Talk. The list contains exactly 1000 Polish hosting companies currently active on the Polish market. Of that thousand, 030 had autonomous systems and 61 reported errors.

The autonomous system of the French OVH systems turned out to be the unquestionable leader in this ranking, using 183 hosting companies. The German company HETZNER-AS Hetzner Online AG RZ came in second with 106 companies. Our very own TPNET came in third with just 33 companies.


Building our own PBN based on our own servers or an account, we can diversify the IP addresses we use. We need to remember to maintain this diversification on every level, simultaneously diversifying C classes and the autonomous systems that provide them. The second pillar of building your own PBN are domains. When managing domains, we can use DNS diversification and the creation of private DNSes as well as diversifying data about the owner of the domain.