IP Address increased controlled way at C#

Question

I just want to automatically increase and get IP address which started from any IP range.

For example,

10.1.1.255 (passed value that IP to function)
10.1.2.1 (third octet changed, fourth octet set to '1')

or

10.1.2.11 (passed value that IP to function)
10.1.2.12 (third octet stable, fourth octet increased)

Is is possible to do this like above controlled way?

Be careful, depending on your netmask `10.1.1.255` can be a broadcast address. — Frédéric Hamidi, Aug 29 '14 at 09:16
The duplicates required OP to have the IP address as a byte array, which he doesn't. — Rawling, Aug 29 '14 at 09:34

score 3 · Answer 1 · answered Aug 29 '14 at 13:37

To offer another possible solution, you could use an Extension method on the System.Net.IPAddress class like so:

public static class MyExtensions
{
    public static System.Net.IPAddress Increment(this System.Net.IPAddress value)
    {
        var ip = BitConverter.ToInt32(value.GetAddressBytes().Reverse().ToArray(), 0);
        ip++;
        return new System.Net.IPAddress(BitConverter.GetBytes(ip).Reverse().ToArray());
    }
}

Then, you would use it like this:

var ipAddress = IPAddress.Parse("10.1.1.255");
var newIpAddress = ipAddress.Increment();

Patrick Hofman · Accepted Answer · 2014-08-29T09:35:45.323

1

Try this one:

string[] i = "10.1.1.255".Split('.');

long n = Convert.ToInt64(i[0]) * (long)Math.Pow(256, 3)
        + Convert.ToInt64(i[1]) * (long)Math.Pow(256, 2)
        + Convert.ToInt64(i[2]) * 256
        + Convert.ToInt64(i[3]);

n++;

n = n % (long)Math.Pow(256, 4);

string next = string.Format("{0}.{1}.{2}.{3}", n / (int)Math.Pow(256, 3), (n % (int)Math.Pow(256, 3)) / (int)Math.Pow(256, 2), (n % (int)Math.Pow(256, 2)) / 256, n % 256);

It splits the IP address in pieces. Calculates a numeric value of it. Then it adds one to get the next, check for overflow. Then it outputs the next value.

edited Aug 29 '14 at 09:35

answered Aug 29 '14 at 09:25

Patrick Hofman

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Lol. Figuring out how to fix it. Thanks. – Patrick Hofman Aug 29 '14 at 09:35
@Rawling: I think the easy option is to use `long`. Can you agree with that? – Patrick Hofman Aug 29 '14 at 09:39
1

Either `long` and modulo it or `uint` and let it wrap around to `0` by itself. I half expected it would work with `int` but I suppose you end up with some negative "bytes". – Rawling Aug 29 '14 at 09:42
Yes, indeed. It becomes negative. Thanks. – Patrick Hofman Aug 29 '14 at 09:42

IP Address increased controlled way at C#

2 Answers2