Check if an IP address is in a range

[countdrak]

Is there a way to check if an IP address is in a subnet range? say I have the IP range 10.10.0.0 - 10.10.255.255 and a subnet of 255.255.0.0 and am given the IP 10.10.50.1

and want to verify that it is in that range.. thanks!

Is there a coldfusion way of doing this?

 

[philhege]

You can, I guess.

Build from this example:
<cfset csublow = 0>
<cfset csubhigh = 255>
<cfset dsublow = 0>
<cfset dsubhigh = 255>
<cfset ctest = 254>
<cfset dtest = 1>

<cfif (csublow LTE ctest AND ctest LTE csubhigh) AND (dsublow LTE dtest and dtest LTE dsubhigh)>
YES
<cfelse>
NO
</cfif>

You can add the code to parse submitted values, evaluate the subnet mask, etc.

HTH,

Phil Hegedusich
Senior Programmer/Analyst
IIMAK

http://www.iimak.com

-----------
Pity the insomniac dyslexic agnostic. He stays up all night, wondering if there really is a dog.

 

[countdrak]

I dont think this logic will work in all cases.

What if my ip is 123.23.254.1? This ip is not in my subnet. But you never compare the A and the B.

 

[philhege]

My code is a simple example of what you can do. As I said, you'll have to write the code to handle all of the situations. I suggest passing the lower-range IP, the upper-range IP, the subnet mask, and the target IP to a function that evaluates based on the subnet mask.

Happy coding!