Is it illegal to track someone’s IP address .?

It depends on what you want to do with that track.

It's not illegal, but it's not very useful either. It will tell you where their ISP server connects to the Internet backbone. This could be hundreds of miles from there actual location.

In the days when dial-up was king someone in New York could dial into an ISP in New Zealand or Australia. You could trace the IP and might be 10000 miles from their true location.

With modern ISPs, particularly large ones, the ISP may carry the connection many miles over their own network before reaching the server that connects to the Internet and has the actual IP address.

I have a dynamic IP address from my ISP. My location can be anywhere from my nearest city to a city 150 to 200 miles away, depending which address I get. The ISP will route through their own network to different servers depending on network and server loadings when I connect to the Internet.

I hope this helps.

No, IP addresses are just out there for anyone to see if you know how to find it.

No companies do it all the time if you slander someone they can track your IP address and sue you and you can’t counter sue them for track and your IP .

Yes, you could get in trouble. IP addresses are considered personal information. Tracking someone's IP address without their permission is similar to stalking.

It's illegal.