how to get my system IP ?

I have set some rights in Pertuculer IP so what can i do

i have create code  like

string strHostName = Dns.GetHostName();
        IPHostEntry ipEntry = Dns.GetHostEntry(strHostName);

        lblIPAddress.Text = Convert.ToString(ipEntry.AddressList[1]);
        lblHostName.Text = Convert.ToString(ipEntry.HostName);


        //Find IP Address Behind Proxy Or Client Machine In ASP.NET
        string IPAdd = string.Empty;
        IPAdd = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

        if (string.IsNullOrEmpty(IPAdd))
        {
            IPAdd = Request.ServerVariables["REMOTE_ADDR"];
            lblIPBehindProxy.Text = IPAdd;
        }

Out Put :2001:0:4137:9e76:1c7d:20c:3f57:fe4d

my IP is :192.168.1.178 is not get