Block IP by "Group Of Computers"

14 Sep 2006 1:27 PM

DBLWizard

Hello,

I am having problems with certain companies that are "scraping" data
from websites and I want to block the IP ranges owned by those
companies. How do you figure out what the subnet mask to block a range
of computers?

Lets say that I want to block 10.10.32.0 - 10.10.63.255 and yes I know
that 10.10 is not a public IP address I use those only as an example
here. What would the subnet mask be to block these in IIS?

I realize that I would probably have to put in several entries such as:
10.10.32.0 would be one and the subnet might be 255.255.255.0 and then
I would have to put in 32 entries. Is there a better way and if so how
can I figure out what the subnet should be.

Thanks

dbl

14 Sep 2006 1:37 PM

Chad Mahoney

DBLWizard wrote:
Show quoteHide quote

> Hello,
>
> I am having problems with certain companies that are "scraping" data
> from websites and I want to block the IP ranges owned by those
> companies. How do you figure out what the subnet mask to block a range
> of computers?
>
> Lets say that I want to block 10.10.32.0 - 10.10.63.255 and yes I know
> that 10.10 is not a public IP address I use those only as an example
> here. What would the subnet mask be to block these in IIS?
>
> I realize that I would probably have to put in several entries such as:
> 10.10.32.0 would be one and the subnet might be 255.255.255.0 and then
> I would have to put in 32 entries. Is there a better way and if so how
> can I figure out what the subnet should be.
>
> Thanks
>
> dbl
>

The subnet would be 255.255.224.0

You get this by:

32 class C subnets, 256*32=8192 IP address'

http://www.zytrax.com/tech/protocols/ip-classes.html