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Q&A How effortlessly can universities check where you logged in? What other IT details can they determine?

Accessing any server involves sending from a particular IP address to a particular IP address; the exchange of packets includes the sender so that the recipient can send packets back. An IP addres...

posted 2y ago by dsr‭

Answer
#1: Initial revision by user avatar dsr‭ · 2021-10-14T00:00:50Z (over 2 years ago)
Accessing any server involves sending from a particular IP address to a particular IP address; the exchange of packets includes the sender so that the recipient can send packets back.

An IP address belongs to an Autonomous System (or AS) which is generally a large entity on the Internet. Any IP address can immediately be linked with the AS.

Most AS assign specific IPs to specific geographical areas. They give IPs names in the DNS that reflect those areas. The names can be looked up from the DNS (via a reverse DNS query).

A traceroute command can show the current path between an originating IP and a target IP. Here's one, which I'm abbreviating:

HOST: DNSChecker.org
*  2.|-- 10.74.8.40 
*  3.|-- 138.197.248.236 
*  4.|-- 138.197.248.56 
*  5.|-- 138.197.244.24
*  6.|-- eqix-ny1.imperva.com (198.32.118.20)
*  7.|-- 45.60.75.209 

The 10.74.8.40 address is an RFC1918 address which is purely internal. 138.197.248.236 can be looked up and shows that it belongs to Digital Ocean. So do the next two. eqix-ny1 is almost certainly a router that talks to the Equinix network in New York City. Finally, the 45.60.75.209 address belongs to Imperva. Imperva is a DDOS protection company, and so our story ends, somewhere in New York City.

It is common for consumer ISPs to have DNS names that are significant down to the city, town or, sometimes, neighborhood.

So: your university staff can likely tell which ISP you are using in what city, but not necessarily your precise address. For that, they would have to ask the ISP who used that IP at a given time, and the ISP would almost certainly ask for a valid subpoena or court order.