What does Class C IP Address means?

[nixhexum]

I was wondering if what does Class C IP Address means? How does it affect our SEO efforts? How do we know if a certain website is in a Class C IP add?

[williamrs]

This is not a very simple explanation...

Class A - 255.xxx.xxx.xxx
Class B - 255.255.xxx.xxx
Class C - 255.255.255.xxx

Your are going to use it when building a computers network. That will determine the number of hosts and sub-networks available and many other things.

You can't determine what's the class of an IP unless you have the number of bits. E.g. 255.255.255.255/24 (this would be a Class C). For each group of numbers we have 8 bits.

I'm not a specialist so I can't give you more accurate information. Maybe you can find something here: IP address - Wikipedia, the free encyclopedia.

Anyway, I have no idea on how it can affect your SEO efforts...


William

[jvvlimme]

Every website "yourdomain.com" translates to a numeric address that computers use in the form of "xxx.xxx.xxx.xxx". Each web host will have some IP adresses assigned to them, usually one or more class C blocks of IP addresses this would be like: 123.456.789.1, 123.456.789.2, 123.456.789.3, ... , 123.456.789.255.

When the google bot spiders your website, it will look at your IP address and that of any of the websites linking to your website. If they find that there are many websites linking to yours from the same class C ip range, this is an indication that they are all on the same webhost and possible have the same owner. Because of that google might think that you are trying to scam them (if there are other indicators for this) and reduce the value of those links.

[bocephus]

Great explanation.

Just a bit more detail... in the case of 123.456.789.X above, "class C" basically refers to which numbers can change in the address. Technically speaking, a class C subnet is a fixed block of addresses with a mask of 255.255.255.0, meaning only the last set of numbers change. This would logically be the smallest block a host would own. So in this case, any address in the range 123.456.789.1 through 123.456.789.254 would be considered part of the same class C subnet.

The reality is, though, that hosting providers get addresses in much larger chunks than class C, the address you see when you resolve your domain name to an ip number is more likely part of something closer to a class B netblock.

In practice, if you have an account with... let's say... HostMonster, every domain you assign to that account will probably resolve to the exact same ip address because your account is on a single server. Only by creating a separate account (and subsequently paying the same yearly fees as the original account) can you possibly get more domains hosted on a separate server with a separate address (and hopefully an address outside of the class C subnet of your original account).

So if you have any intention of creating networks of web sites that link to each other, then you would be advised to purchase separate accounts with separate hosting services.

[McMoney]

Every computer on the Internet has an IP address. Your computer and the server that hosts your websites all have IP addresses. They usually look something like this:

74.124.141.97

As you see above, there are 4 sets of numbers separated by dots.

The first set of numbers is the ‘A’ class
The second set is the ‘B’ class
The third set of numbers the ‘C’ class
And finally the fourth set is the ‘D’ class

Something a bit like this:

A.B.C.D

Inside data centers where your server is located related servers or websites are often hosted by servers with the same ‘C’ class of ips. So their ips might look something like this:

74.124.141.97
74.124.141.87

The search engines know this and can spot when related sites cross link to each other from within the same class C ip address. These links are often filtered out of the ranking algorithms. If your site has too many of these types of links it can even bring a penalty to your site.

[paulgl]

google is smart enough to know who is trying to
manipulate results. And they are smart enough to
know those who aren't. IPs don't matter unless
you are worried about doing something to fool
google. If you wish to be banned by google, keep
thinking of ways to tweak google without doing
any hard work. Forget class c nonsense, and the
underlying talk of trying to use them to do
something to skew or fool google.

Paul