Let say I have done something harmful to some computer.

I am on wifi at my hostel, so for that session I have some IP assigned. Now, since tomorrow I will connect again to wifi and get a new IP Address, how will they (FBI or anyone) trace me?

I read this article, but I am not convinced.

I want to know if it is really possible to trace the computer, if it was assigned to a dynamic IP.

For example, let say I was assigned for today and I performed some illegal activity on someone else's computer. Tomorrow when I connect to the wifi of my hostel, the IP will be different. So how will they trace my computer? Do they trace by MAC address, does the ISP record MAC for every IP assigned?

  • 3
    Why weren't you convinced? What are the points you didn't like? Because I think that the article did a very good job explaining your question. – Adi May 13 '13 at 5:31
  • hmm i want more in depth info like how it is actually done , article is good but it lacks practical example , can u gve ? – anshulkatta May 13 '13 at 5:32
  • add more details to your question – Shurmajee May 13 '13 at 5:33
  • 1
    @MayankSharma When the OP's question is vague it's not usually recommended to respond with a vague comment. If more information is needed, we can simply explain the kind of information needed to make the question clearer. – Adi May 13 '13 at 5:36
  • 3
    To be honest, I don't really like this question. It's unclear, reeks of a lack of fundamentals, and looks like a scriptkiddie haxoring attempt with only the façade of a real question. Voted to close. – Adi May 13 '13 at 6:15

Yes and no.

Yes it can be traced to your ISP, ergo to the geographical area in which your ISP exists. This is more often that not where you live. But no, it can't be easily and directly traced to you.

It is required by law to provide correct information when reserving Internet resources (domain names, IP addresses), those information are stored in a publicly accessible WHOIS database. Since your ISP is the one who reserved a stack of IP addresses, they usually are linked to it. If you are assigned an IP address dynamically and you lookup your IP address in WHOIS database, it leads to your ISP.

When the authorities want to trace you even more (beyond just the ISP level) they simply provide a legal request (such as subpoena) to your ISP with the time of your activity. Your ISP simply looks up their database and see who was given that IP address at the that time. After they know it's you, they simply hand over your registration information (Full name, address, etc.).

In the case of static IP addresses, things are a little bit different. Depending on the jurisdiction and possibly your ISP policies, your statically assigned IP address maybe linked directly to your identity and thus can be looked up in a WHOIS database. Some ISPs provide a domain-privacy-like service for your static IP, in which they keep the IP publicly linked directly to them. Again, in this case, a legal request can be filed and the ISP will hand out your real information.

In your question you mentioned something about connecting to WiFi again and getting a new IP address. Even though you're getting a new local IP address, your public IP address is still the same. That's because almost all home routers and WiFi access points create a NAT by which they separate your home network from the outside world, and no matter what IP address you have inside the local network, the world still sees the same public IP address.

| improve this answer | |
  • 2
    @anshulkatta It depends on the router/WiFi access point. Most of the ones I've seen only provide a log of the currently leased IP addresses. Depending on the router's configurations, the lease might be up upto several weeks. I've seen many home routers default to a lease time of 1 week. The DHCP log usually contains the IP address, the MAC address, and the time of the lease. – Adi May 13 '13 at 6:06
  • 2
    @anshulkatta But remember, hostels have security cameras, guest logs, and eyewitnesses. It's not gonna be difficult to find the teenager with the laptop. – Adi May 13 '13 at 6:09
  • 3
    @anshulkatta Hey hey hey! Hey there you! Take it easy alright? Let's just remain polite! That's not a way to address our members here. Everybody has been polite with you, we expect you to do the same. – Adi May 13 '13 at 6:18
  • 1
    @anshulkatta security.SE is a community for enthusiastic security professionals. The more you explore this site the more you will understand how and why and how it is different from other forums. Be patient and learn from others. security.stackexchange.com/faq – Shurmajee May 13 '13 at 6:40
  • 1
    @anshulkatta, welcome to Information Security. Please keep a civil tone. Rule #1 of StackExchange: BE NICE. Please review the FAQ, and also How to Ask, before continuing on the site. – AviD May 13 '13 at 6:55

Not the answer you're looking for? Browse other questions tagged or ask your own question.