IPAddress Class
Provides an Internet Protocol (IP) address.
For a list of all members of this type, see IPAddress Members.
System.Object
System.Net.IPAddress
[Visual Basic] <Serializable> Public Class IPAddress [C#] [Serializable] public class IPAddress [C++] [Serializable] public __gc class IPAddress [JScript] public Serializable class IPAddress
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
The IPAddress class contains the address of a computer on an IP network.
Example
[Visual Basic, C#, C++] The following code example shows how to query a server to obtain the family addresses and the IP addresses it supports.
[Visual Basic] ' This program shows how to use the IPAddress class to obtain a server ' IP addressess and related information. Imports System Imports System.Net Imports System.Net.Sockets Imports System.Text.RegularExpressions Imports Microsoft.VisualBasic Namespace Mssc.Services.ConnectionManagement Module M_TestIPAddress Class TestIPAddress 'The IPAddresses method obtains the selected server IP address information. 'It then displays the type of address family supported by the server and 'its IP address in standard and byte format. Private Shared Sub IPAddresses(ByVal server As String) Try Dim ASCII As New System.Text.ASCIIEncoding() ' Get server related information. Dim heserver As IPHostEntry = Dns.Resolve(server) ' Loop on the AddressList Dim curAdd As IPAddress For Each curAdd In heserver.AddressList ' Display the type of address family supported by the server. If the ' server is IPv6-enabled this value is: InternNetworkV6. If the server ' is also IPv4-enabled there will be an additional value of InterNetwork. Console.WriteLine(("AddressFamily: " + curAdd.AddressFamily.ToString())) ' Display the ScopeId property in case of IPV6 addresses. If curAdd.AddressFamily.ToString() = ProtocolFamily.InterNetworkV6.ToString() Then Console.WriteLine(("Scope Id: " + curAdd.ScopeId.ToString())) End If ' Display the server IP address in the standard format. In ' IPv4 the format will be dotted-quad notation, in IPv6 it will be ' in in colon-hexadecimal notation. Console.WriteLine(("Address: " + curAdd.ToString())) ' Display the server IP address in byte format. Console.Write("AddressBytes: ") Dim bytes As [Byte]() = curAdd.GetAddressBytes() Dim i As Integer For i = 0 To bytes.Length - 1 Console.Write(bytes(i)) Next i Console.WriteLine(ControlChars.Cr + ControlChars.Lf) Next curAdd Catch e As Exception Console.WriteLine(("[DoResolve] Exception: " + e.ToString())) End Try End Sub 'IPAddresses ' This IPAddressAdditionalInfo displays additional server address information. Private Shared Sub IPAddressAdditionalInfo() Try ' Display the flags that show if the server supports IPv4 or IPv6 ' address schemas. Console.WriteLine((ControlChars.Cr + ControlChars.Lf + "SupportsIPv4: " + Socket.SupportsIPv4.ToString())) Console.WriteLine(("SupportsIPv6: " + Socket.SupportsIPv6.ToString())) If Socket.SupportsIPv6 Then ' Display the server Any address. This IP address indicates that the server ' should listen for client activity on all network interfaces. Console.WriteLine((ControlChars.Cr + ControlChars.Lf + "IPv6Any: " + IPAddress.IPv6Any.ToString())) ' Display the server loopback address. Console.WriteLine(("IPv6Loopback: " + IPAddress.IPv6Loopback.ToString())) ' Used during autoconfiguration first phase. Console.WriteLine(("IPv6None: " + IPAddress.IPv6None.ToString())) Console.WriteLine(("IsLoopback(IPv6Loopback): " + IPAddress.IsLoopback(IPAddress.IPv6Loopback).ToString())) End If Console.WriteLine(("IsLoopback(Loopback): " + IPAddress.IsLoopback(IPAddress.Loopback).ToString())) Catch e As Exception Console.WriteLine(("[IPAddresses] Exception: " + e.ToString())) End Try End Sub 'IPAddressAdditionalInfo Public Shared Sub Main(ByVal args() As String) Dim server As String = Nothing ' Define a regular expression to parse user's input. ' This is a security check. It allows only ' alphanumeric input string between 2 to 40 character long. 'Define a regular expression to parse user's input. 'This is a security check. It allows only 'alphanumeric input string between 2 to 40 character long. Dim rex As New Regex("^[a-zA-Z]\w{1,39}$") If args.Length < 1 Then ' If no server name is passed as an argument to this program, use the current ' server name as default. server = Dns.GetHostName() Console.WriteLine(("Using current host: " + server)) Else server = args(0) If Not rex.Match(server).Success Then Console.WriteLine("Input string format not allowed.") Return End If End If ' Get the list of the addresses associated with the requested server. IPAddresses(server) ' Get additonal address information. IPAddressAdditionalInfo() End Sub 'Main End Class 'TestIPAddress End Module End Namespace [C#] // This program shows how to use the IPAddress class to obtain a server // IP addressess and related information. using System; using System.Net; using System.Net.Sockets; using System.Text.RegularExpressions; namespace Mssc.Services.ConnectionManagement { class TestIPAddress { /** * The IPAddresses method obtains the selected server IP address information. * It then displays the type of address family supported by the server and its * IP address in standard and byte format. **/ private static void IPAddresses(string server) { try { System.Text.ASCIIEncoding ASCII = new System.Text.ASCIIEncoding(); // Get server related information. IPHostEntry heserver = Dns.Resolve(server); // Loop on the AddressList foreach (IPAddress curAdd in heserver.AddressList) { // Display the type of address family supported by the server. If the // server is IPv6-enabled this value is: InternNetworkV6. If the server // is also IPv4-enabled there will be an additional value of InterNetwork. Console.WriteLine("AddressFamily: " + curAdd.AddressFamily.ToString()); // Display the ScopeId property in case of IPV6 addresses. if(curAdd.AddressFamily.ToString() == ProtocolFamily.InterNetworkV6.ToString()) Console.WriteLine("Scope Id: " + curAdd.ScopeId.ToString()); // Display the server IP address in the standard format. In // IPv4 the format will be dotted-quad notation, in IPv6 it will be // in in colon-hexadecimal notation. Console.WriteLine("Address: " + curAdd.ToString()); // Display the server IP address in byte format. Console.Write("AddressBytes: "); Byte[] bytes = curAdd.GetAddressBytes(); for (int i = 0; i < bytes.Length; i++) { Console.Write(bytes[i]); } Console.WriteLine("\r\n"); } } catch (Exception e) { Console.WriteLine("[DoResolve] Exception: " + e.ToString()); } } // This IPAddressAdditionalInfo displays additional server address information. private static void IPAddressAdditionalInfo() { try { // Display the flags that show if the server supports IPv4 or IPv6 // address schemas. Console.WriteLine("\r\nSupportsIPv4: " + Socket.SupportsIPv4); Console.WriteLine("SupportsIPv6: " + Socket.SupportsIPv6); if (Socket.SupportsIPv6) { // Display the server Any address. This IP address indicates that the server // should listen for client activity on all network interfaces. Console.WriteLine("\r\nIPv6Any: " + IPAddress.IPv6Any.ToString()); // Display the server loopback address. Console.WriteLine("IPv6Loopback: " + IPAddress.IPv6Loopback.ToString()); // Used during autoconfiguration first phase. Console.WriteLine("IPv6None: " + IPAddress.IPv6None.ToString()); Console.WriteLine("IsLoopback(IPv6Loopback): " + IPAddress.IsLoopback(IPAddress.IPv6Loopback)); } Console.WriteLine("IsLoopback(Loopback): " + IPAddress.IsLoopback(IPAddress.Loopback)); } catch (Exception e) { Console.WriteLine("[IPAddresses] Exception: " + e.ToString()); } } public static void Main(string[] args) { string server = null; // Define a regular expression to parse user's input. // This is a security check. It allows only // alphanumeric input string between 2 to 40 character long. Regex rex = new Regex(@"^[a-zA-Z]\w{1,39}$"); if (args.Length < 1) { // If no server name is passed as an argument to this program, use the current // server name as default. server = Dns.GetHostName(); Console.WriteLine("Using current host: " + server); } else { server = args[0]; if (!(rex.Match(server)).Success) { Console.WriteLine("Input string format not allowed."); return; } } // Get the list of the addresses associated with the requested server. IPAddresses(server); // Get additonal address information. IPAddressAdditionalInfo(); } } } [C++] #using <mscorlib.dll> #using <System.dll> using namespace System; using namespace System::Net; using namespace System::Net::Sockets; /** * The IPAddresses method obtains the selected server IP address information. * It then displays the type of address family supported by the server and its * IP address in standard and Byte format. **/ void IPAddresses(String* server) { try { System::Text::ASCIIEncoding* ASCII = new System::Text::ASCIIEncoding(); // Get server related information. IPHostEntry* heserver = Dns::Resolve(server); // Loop on the AddressList System::Collections::IEnumerator* myEnum = heserver->AddressList->GetEnumerator(); while (myEnum->MoveNext()) { IPAddress* curAdd = __try_cast<IPAddress*>(myEnum->Current); // Display the type of address family supported by the server. If the // server is IPv6-enabled this value is: InternNetworkV6. If the server // is also IPv4-enabled there will be an additional value of InterNetwork. Console::WriteLine(S"AddressFamily: {0}", __box( curAdd->AddressFamily)); // Display the server IP address in the standard format. In // IPv4 the format will be dotted-quad notation, in IPv6 it will be // in in colon-hexadecimal notation. Console::WriteLine(S"Address: {0}", curAdd); // Display the server IP address in Byte format. Console::Write(S"AddressBytes: "); Byte bytes[] = curAdd->GetAddressBytes(); for (int i = 0; i < bytes->Length; i++) { Console::Write(bytes->Item[i]); } Console::WriteLine(S"\r\n"); } } catch (Exception* e) { Console::WriteLine(S"->Item[DoResolve] Exception: {0}", e); } } // This IPAddressAdditionalInfo displays additional server address information. void IPAddressAdditionalInfo() { try { // Display the flags that show if the server supports IPv4 or IPv6 // address schemas. Console::WriteLine(S"\r\nSupportsIPv4: {0}", __box( Socket::SupportsIPv4)); Console::WriteLine(S"SupportsIPv6: {0}", __box( Socket::SupportsIPv6)); if (Socket::SupportsIPv6) { // Display the server Any address. This IP address indicates that the server // should listen for client activity on all network interfaces. Console::WriteLine(S"\r\nIPv6Any: {0}", IPAddress::IPv6Any); // Display the server loopback address. Console::WriteLine(S"IPv6Loopback: {0}", IPAddress::IPv6Loopback); // Used during autoconfiguration first phase. Console::WriteLine(S"IPv6None: {0}", IPAddress::IPv6None); Console::WriteLine(S"IsLoopback(IPv6Loopback): {0}", __box( IPAddress::IsLoopback(IPAddress::IPv6Loopback))); } Console::WriteLine(S"IsLoopback(Loopback): {0}", __box( IPAddress::IsLoopback(IPAddress::Loopback))); } catch (Exception* e) { Console::WriteLine(S"->Item[IPAddresses] Exception: {0}", e); } } int main() { String* args[] = Environment::GetCommandLineArgs(); String* server; if (args->Length == 1) // If no server name is passed as an argument to this program, use the current // server name as default. server = Dns::GetHostName(); else server = args[1]; // Get the list of the addresses associated with the requested server. IPAddresses(server); // Get additonal address information. IPAddressAdditionalInfo(); }
[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Namespace: System.Net
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework
Assembly: System (in System.dll)