alcazar

iTrader: (2)

Can it be done? By a layman, for example?

Anyone care to run me through it?

birchy2010

iTrader: (12)

I'm confused, you want to find out who your internet service provider is?

Markus

I'm going to guess you have someone's IP address from somewhere, perhaps it has tried to connect to your machine?
If so then the whois command is your friend. I know for sure it's in OS X, not sure about windows (does not seem to be in XP by default - There are websites to lookup whois info, do a search for whois / whois ip address) but what you would do is this (I'll assume it's in windows at this point)

Fire up Terminal / Command Prompt and enter:
whois 000.000.000.000

where 000.000.000.000 is the IP address you have (if it's not an ip address but a domain, e.g.; bongo dot com, put that in instead)

Hit return and it it should spew out information. NetName and OrgName might give you contact information for who hosts that IP address / domain. You could then contact whomever is listed there to try and get more info as to who was using the IP address / domain, however, due to privacy laws you probably won't get any info back unless you get the police involved, and they could ask for the info.

evorach

iTrader: (6)

Alternatively Google the IP and it should come up with the provider.

alcazar

iTrader: (2)

What if you receive something and need to find what IP address it came from?
Like an e-mail, for example?

phoenixgold

iTrader: (2)

For an e-mail, you need to view the e-mail source. This will contain all the routing information for the message, including the original ip details.

Getting to the source view will be different for each e-mail client. If you post what e-mail client you are using, I'll try an point you in the right direction.

alcazar

iTrader: (2)

Do you mean the isp of the person receiving the e-mail?

Markus

As mentioned by others, view the raw headers / long source of the message and it should list things like "received from", "sender info" and things like that. This will tell you the server that sent it.

If, for example, someone has their own server, or sent it via a company mail server then that gives you one step to look at, however, the server could be an open-relay and so someone is using it to spoof / bounce the message to make it look as though it's come from that server when it has not.

If they have used gmail, well, you'd probably get the gmail server info back, which might give info on where it was sent from (IP address of sending computer), so you could look that up.

If some kind of abuse / threat has been via email and you are concerned then you should contact the police and see if they can help, or post it on 4chan and let them do their worst on the sender