I keep noticing that web pages I have open are exchanging messages with third party servers without my permission. This is somewhat annoying, and I would like to find out which pages they are so I can close them. I copied an IP address - 18.104.22.168 - from the TCPdump output, and Googled "reverse dns lookup 22.214.171.124" to see if I could find a hostname that would give me a clue as to the URL of the page and indicate which tab I should close (I tend to have like 20 to 50 tabs open at a time because I can't close anything). I got the website lookip.net, which told me that there was no reverse DNS lookup found.
So I would like to know what is the reason for this. Is this a bad lookup service? Would I have better luck using a different one? Or does this host just not have a hostname associated with it (that doesn't make sense; I thought all hosts had hostnames associated with them).
I know that if this is a third party server, the hostname wouldn't be the same as the site that's sending the packets, but it would at least be a good starting point. I'm not very good at this, but it's something I could get better at as I learn more about how this stuff works. Right now I'm just a novice at this networking stuff. All I have to work with is a basic understanding of networking principles and TCP/IP. I would like to learn more. A lot more.