IP Address Ranges for Major ISP's

Trying to efficiently monitor against click fraud

[deluxcougar]

I am trying to check my log files against any click fraud that may have happened. Rather than checking every IP address that comes in, I am trying to find a list of IP blocks used by the major isp's so I can filter those out. Anyone know where I can find a list or can I get this info from each site individually?

[digitalv]

You can purchase an IP Database with ISP Information from www.ip2location.com, I think that comes with a year of updates too.

[deluxcougar]

That seems far too complex and expensive for what I am hoping to get. Any other places you know of? I'm really just looking for a semi-comprehensive list of IP's for the major isps.

[deluxcougar]

DigitalV, Thanks for the suggestion though