A/B/n testing, how to distribute web site client?

Question

In standard A/B testing, we can use the parity of the ip adresse to distribute the client to A or B testing page.

My question is how to distribute when we need 3 case: A/B/C. If someone know to code or has already coded this for asp.net in c#, I will be happy to know !

Sinn'

Answer 1

Convert the ip to long, and then just make a module divide

    switch(addrToNum("ip address")%3)
    {
        case 0:
            break;
        case 1:
            break;
        case 2:
            break;
    }

and here is the convertion of the ip to number

    public long addrToNum(IPAddress Address)
    {
        byte[] b = BitConverter.GetBytes(Address.Address);

        if (b.Length == 8)
            return (long)(((long)16777216 * b[0]) + ((long)(65536 * b[1])) + ((long)(256 * b[2])) + b[3]);
        else
            return 0;
    }