//获取客户端的IP地址
TextBox1.Text = Request.UserHostAddress;
//获取服务器的主机名
string hostName = Dns.GetHostName();
//获取服务器的IP地址
IPAddress[] ips;
ips = Dns.GetHostAddresses(hostName);
foreach ( IPAddress ip in ips)
{
TextBox2.Text = ip.ToString();
}