I have seven websites hosted with the same provider, all part of the same hosting plan. Yesterday I visited all my sites one after another and looked at the Apache access logs. At that time, several What-is-your-IP? sites gave my IP as (I have anonymized the last parts for this question):
IPv4 84.143.222.xxx IPv6 2003:df:972e:xxx:xxx:xxx:xxx:xxx
In my logs, my visits where registered with the following IPs (IPs are anonymized in the logfiles due to European data protection laws):
2003:df:9700:: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Firefox/60.0 18.104.22.168 Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A 22.214.171.124 Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.75.14 (KHTML, like Gecko) Version/7.0.3 Safari/7046A194A
How can that be?
It looks as if someone else must have visited my sites. But I have visited my sites in a certain order, and several sites are missing from the logs if I only look at the visits from the one IPv6. If I add the visits from the two IPv4 addresses, the pattern of my visits is complete.
Also, my sites are not connected together for visitors in any way. There are no links between them, they have different topics, and different persons and addresses are given in the imprint and TOS. For anyone except myself (and the hosting provider) they must appear completely unrelated. And yet the two IPv4 visits where to all of my seven sites.
It is extremely unlikely that anyone would know all these sites belong together and visit them all one after another at the same time I visit them in the exact same order.
So what's going on?
Host is Debian GNU/Linux 8.10 (jessie) Kernel is 3.16.0-ui18135.21-uiabi1-infong-amd64