hosting guys: how do you find out
 

what companies hosts buy their bandwidth from?

That's easy. They buy them from the carriers - which are often the old telephonecompanies who offers bandwidth. They can also buy/swap it on the Internext exchanges around the world for peering. And they make actual peering agreements as well.

Wow! That was super helpful! I'm sure you helped him a lot!

.. Idiot.

You must be the idiot. GFY :1orglaugh

Traceroutes are always a great place to start.....

I'm the idiot. Yet it's pretty fucking obvious to me that he was wanting to find out how to find out what particular bandwidth provider a host was using. It wasn't obvious to you? Idiot.

www.arin.net -- good place to start

Put in the IP address of the host's page. First... if it comes back as a company other than the one you are looking up (such as Level3), then the host is *likely single-homed just to that provider.

If it comes back with an orgname as the hosting provider you were looking for, then you can see all their **peering relationships here (with the same IP):

http://www.fixedorbit.com/search.htm

That's a handy tool. Cheers!

Do you want me to name all the carriers and peering points??
Or what's your advice, let me know and I'll try ;-)

thats exactly what i wanted to know

Or you could quite simply answer his question like Jeff did.