To properly understand what class c IPs is, consider the example of an IP of 54.26.98.20
. This is where 54 is part A, 26 is part B, 98 is part C and 20 is part D. when deciding whether an IP originated from the same host, a search engine like Yahoo or Google will usually check the class c IPs. If two diverse websites have the class c IPs that are same, all the links connecting those two websites will be sandboxed and as such will not count in Google. However if there are multiple class c IPs, it is considered a big plus point and your value would be counted.