More fun with IPs, this time converting them to integers.

<cffunction name="IPtoInt" output="false" returntype="struct"
    hint="Returns a struct with two nodes<br />
    Start: The starting IP address for the range specified<br />
    End: The last IP address in the range
    Range: Number of IP Addresses in the range"
>
    <cfargument name="IPAddress" type="string" required="true" hint="" />

    <cfset var LOCAL = StructNew() />
    <cfset LOCAL.retVal = StructNew() />
    <cfset LOCAL.retVal.range = 0 />
    <cfif ListLen(Arguments.IPAddress, ".") LT 4>
        <cfset LOCAL.retVal.range = 255^(4-ListLen(Arguments.IPAddress, ".")) />
        <cfloop from="1" to="#4-ListLen(Arguments.IPAddress, ".")#" index="LOCAL.i">
            <cfset Arguments.IPAddress &= ".0" />
        </cfloop>
    </cfif>

    <cfset LOCAL.Octets = ListToArray(Arguments.IPAddress, ".") />
    <cfloop array="#LOCAL.Octets#" index="LOCAL.octet">
        <cfif LOCAL.octet LT 0 OR LOCAL.octet GT 255>
            <cfthrow 
                type="exception" 
                message="Invalid Octet" 
                detail="The octet '#LOCAL.octet#' is outside acceptable range. Octets must between 0 and 255."  />
        </cfif>
    </cfloop>

    <cfif LOCAL.Octets[1] LT 128>
        <cfset LOCAL.base = LOCAL.Octets[1] * 16777216 />
    <cfelse>
        <cfset LOCAL.base = -(256 - LOCAL.Octets[1]) * 16777216 />
    </cfif>

    <cfset LOCAL.retVal.Start = LOCAL.base + (LOCAL.Octets[2] * 65536) + (LOCAL.Octets[3] * 256) + (LOCAL.Octets[4]) />
    <cfset LOCAL.retVal.End = LOCAL.retVal.Start + LOCAL.retVal.Range />

    <cfreturn LOCAL.retVal />

</cffunction>