I have a wireless router which connects to the Internet. Do external sites and services know that I'm using a router and it is not a final PC?

For that matter can external services (and perhaps my ISP) find out that I may be using several devices (computers, mobile phones, virtual machines or whatever) to connect to the Internet and not just one? Can they find out the details of the final devices? Like host names, models or whatever?

If so how can I prevent disclosing that information?

  • 1
    Yes and no. The answer is that it depends. Your browser advertises a lot about your computer, including OS, but there are ways to prevent this. Unfortunately your question is too wide open to answer in a concise way. – user3463 Jul 22 '12 at 21:29
  • Yes, I'm aware of the browser issues, that's obvious. I meant short of that is it possible to discover my local network behind the router? – User Jul 22 '12 at 22:17
  • You could mark this as answered? – Everett Aug 13 '12 at 20:38

Assuming you are inside the network that you are asking about, you can go to a website like whatismyip.com and see what your public IP (Internet Protocol) address is. Unless you have requested and are paying for a static IP (one that doesn't change) you likely have a dynamic IP address (one that changes at given points over time). The IP address is like your street address. Information that leaves your network has a return (IP) address on it.

On the opposite side of this public IP address is your internal network. If it is using class A (, class B ( -, or class C ( - private networks, those IP addresses do not travel out into the Internet. Your router uses NAT (Network address translation) to convert between private and public network addresses.

So the short answer is no.

However, by looking at the information a web browser advertises, you can get an idea of the computer type, OS, and browser that is being used. If everyone in a network connects to your server, and you collect this information, you have an idea of whats there. A way to hide this is to use a proxy.

In order for me to get inside the network and see what's there I could use a reverse tunnel, then browse the network from whatever computer I reverse tunneled to inside your network. Realize this is an active attack on your network, not just passive information gathering. Defenses against this attack typically include software patches/updates, firewalls, and IPS/IDS. Let me know if you have any further questions.

  • That was quite good. Thank you. Let me thing about it. Unfortunately I can't give you a +1 since I do not have an account here. Hope the others will thank you for me. – User Jul 23 '12 at 8:17
  • There are no classes anymore. There haven't been since 1993, before most people ever heard of the Internet. – Michael Hampton Jul 23 '12 at 14:04
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    That may be true, but when teaching about private networks, they are often still referred to as class A,B, and C. So much so that I've seen a question recently on a popular certification test as what the network range of a private class b network is. "There are no classes anymore," wasn't one of the options. – Everett Jul 23 '12 at 17:00

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