Ler o nome da máquina e o IP em asp.Net

//le o ip e o hostname do user
                        string Ip="";
                        string HostName = System.Net.Dns.GetHostName().ToString();
                        System.Net.IPHostEntry HostIP = System.Net.Dns.Resolve(HostName); //saca o ip a partir do hostname
                        System.Net.IPAddress [] address = HostIP.AddressList;
                        for(int i = 0;i< address.Length; i++) //ciclo q escreve o ip
                                Ip=(Ip + address[i]);