Csharp/CSharp Tutorial/Windows/Registry Network

Find DNS Servers and get server list

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

  public static void Main()
  {
     RegistryKey start = Registry.LocalMachine;
     string DNSservers = @"SYSTEM\CurrentControlSet\Services\Tcpip\Parameters";
     RegistryKey DNSserverKey = start.OpenSubKey(DNSservers);
     if (DNSserverKey == null)
     {
        Console.WriteLine("Unable to open DNS servers key");
        return;
     }
 
     string serverlist = (string)DNSserverKey.GetValue("NameServer");
     Console.WriteLine("DNS Servers: {0}", serverlist);
     DNSserverKey.Close();
     start.Close();
  }

}</source>

Get default gateway from network key stored in Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

   public static void Main()
   {
     RegistryKey start = Registry.LocalMachine;
     RegistryKey cardServiceName, networkKey;
     string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
     string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
     string networkcardKeyName, deviceName, deviceServiceName, serviceName;
   
     RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
     if (serviceNames == null)
     {
         Console.WriteLine("Bad registry key");
         return;
     }
   
     string[] networkCards = serviceNames.GetSubKeyNames();
     serviceNames.Close();
   
     foreach(string keyName in networkCards)
     {
         networkcardKeyName = networkcardKey + "\\" + keyName;
         cardServiceName = start.OpenSubKey(networkcardKeyName);
         if (cardServiceName == null)
         {
           Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
           return;
         }
         deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
         deviceName = (string)cardServiceName.GetValue("Description");
         serviceName = serviceKey + deviceServiceName + "\\Parameters\\Tcpip";
         networkKey = start.OpenSubKey(serviceName);
         if (networkKey == null)
         {
           Console.WriteLine("    No IP configuration set");
           return;
         }
         string[] defaultGateways = (string[])networkKey.GetValue("DefaultGateway");
         foreach(string defaultGateway in defaultGateways)
         {
             Console.WriteLine("    Gateway: {0}", defaultGateway);
         }
         networkKey.Close();
     }
     start.Close();
   }

}</source>

Get DNS server from Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

  public static void Main()
  {
     RegistryKey start = Registry.LocalMachine;
     string DNSservers = @"SYSTEM\CurrentControlSet\Services\Tcpip\Parameters";
     RegistryKey DNSserverKey = start.OpenSubKey(DNSservers);
     if (DNSserverKey == null)
     {
        Console.WriteLine("Unable to open DNS servers key");
        return;
     }
 
     string serverlist = (string)DNSserverKey.GetValue("NameServer");
     Console.WriteLine("DNS Servers: {0}", serverlist);
     DNSserverKey.Close();
     start.Close();
  }

}</source>

Get IP address from network key stored in Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

   public static void Main()
   {
     RegistryKey start = Registry.LocalMachine;
     RegistryKey cardServiceName, networkKey;
     string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
     string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
     string networkcardKeyName, deviceName, deviceServiceName, serviceName;
   
     RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
     if (serviceNames == null)
     {
         Console.WriteLine("Bad registry key");
         return;
     }
   
     string[] networkCards = serviceNames.GetSubKeyNames();
     serviceNames.Close();
   
     foreach(string keyName in networkCards)
     {
         networkcardKeyName = networkcardKey + "\\" + keyName;
         cardServiceName = start.OpenSubKey(networkcardKeyName);
         if (cardServiceName == null)
         {
           Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
           return;
         }
         deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
         deviceName = (string)cardServiceName.GetValue("Description");
         serviceName = serviceKey + deviceServiceName + "\\Parameters\\Tcpip";
         networkKey = start.OpenSubKey(serviceName);
         if (networkKey == null)
         {
           Console.WriteLine("    No IP configuration set");
           return;
         }
         string[] ipaddresses = (string[])networkKey.GetValue("IPAddress");
       
         foreach(string ipaddress in ipaddresses)
         {
             Console.WriteLine("    IP Address: {0}", ipaddress);
         }
         networkKey.Close();
     }
     start.Close();
   }

}</source>

IP Address: 0.0.0.0
    IP Address: 0.0.0.0

Get Network Card Information from Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

   public static void Main()
   {
     RegistryKey start = Registry.LocalMachine;
     RegistryKey cardServiceName, networkKey;
     string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
     string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
     string networkcardKeyName, deviceName, deviceServiceName, serviceName;
   
     RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
     if (serviceNames == null)
     {
         Console.WriteLine("Bad registry key");
         return;
     }
   
     string[] networkCards = serviceNames.GetSubKeyNames();
     serviceNames.Close();
   
     foreach(string keyName in networkCards)
     {
         networkcardKeyName = networkcardKey + "\\" + keyName;
         cardServiceName = start.OpenSubKey(networkcardKeyName);
         if (cardServiceName == null)
         {
           Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
           return;
         }
         deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
         deviceName = (string)cardServiceName.GetValue("Description");
         Console.WriteLine("\nNetwork card: {0}", deviceName);
     }
   
     start.Close();
   }

}</source>

Network card: Broadcom 802.11b/g WLAN
Network card: Realtek RTL8139/810x Family Fast Ethernet NIC

Get subnet mask from network key stored in Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

   public static void Main()
   {
     RegistryKey start = Registry.LocalMachine;
     RegistryKey cardServiceName, networkKey;
     string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
     string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
     string networkcardKeyName, deviceName, deviceServiceName, serviceName;
   
     RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
     if (serviceNames == null)
     {
         Console.WriteLine("Bad registry key");
         return;
     }
   
     string[] networkCards = serviceNames.GetSubKeyNames();
     serviceNames.Close();
   
     foreach(string keyName in networkCards)
     {
         networkcardKeyName = networkcardKey + "\\" + keyName;
         cardServiceName = start.OpenSubKey(networkcardKeyName);
         if (cardServiceName == null)
         {
           Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
           return;
         }
         deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
         deviceName = (string)cardServiceName.GetValue("Description");
         serviceName = serviceKey + deviceServiceName + "\\Parameters\\Tcpip";
         networkKey = start.OpenSubKey(serviceName);
         if (networkKey == null)
         {
           Console.WriteLine("    No IP configuration set");
           return;
         }
         string[] subnetmasks = (string[])networkKey.GetValue("SubnetMask");
         foreach(string subnetmask in subnetmasks)
         {
             Console.WriteLine("    Subnet Mask: {0}", subnetmask);
         }
         networkKey.Close();
     }
     start.Close();
   }

}</source>

Subnet Mask: 0.0.0.0
    Subnet Mask: 0.0.0.0

Get the network device name, device service name

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

   public static void Main()
   {
     RegistryKey start = Registry.LocalMachine;
     RegistryKey cardServiceName, networkKey;
     string networkcardKey = "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\NetworkCards";
     string serviceKey = "SYSTEM\\CurrentControlSet\\Services\\";
     string networkcardKeyName, deviceName, deviceServiceName, serviceName;
   
     RegistryKey serviceNames = start.OpenSubKey(networkcardKey);
     if (serviceNames == null)
     {
         Console.WriteLine("Bad registry key");
         return;
     }
   
     string[] networkCards = serviceNames.GetSubKeyNames();
     serviceNames.Close();
   
     foreach(string keyName in networkCards)
     {
         networkcardKeyName = networkcardKey + "\\" + keyName;
         cardServiceName = start.OpenSubKey(networkcardKeyName);
         if (cardServiceName == null)
         {
           Console.WriteLine("Bad registry key: {0}", networkcardKeyName);
           return;
         }
         Console.WriteLine(networkcardKeyName);
         deviceServiceName = (string)cardServiceName.GetValue("ServiceName");
         Console.WriteLine(deviceServiceName);
         deviceName = (string)cardServiceName.GetValue("Description");
         Console.WriteLine("Network card: {0}", deviceName);
     }
     start.Close();
   }

}</source>

SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards\11
{4FA13198-E7E5-4065-8395-EDC576EE1020}
Network card: Broadcom 802.11b/g WLAN
SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards\2
{0180EFAF-14BF-42AA-A274-6D8D766A0093}
Network card: Realtek RTL8139/810x Family Fast Ethernet NIC

Parse server list stored in Registry

<source lang="csharp">using System; using Microsoft.Win32; class MainClass {

  public static void Main()
  {
     RegistryKey start = Registry.LocalMachine;
     string DNSservers = @"SYSTEM\CurrentControlSet\Services\Tcpip\Parameters";
     RegistryKey DNSserverKey = start.OpenSubKey(DNSservers);
     if (DNSserverKey == null)
     {
        Console.WriteLine("Unable to open DNS servers key");
        return;
     }
 
     string serverlist = (string)DNSserverKey.GetValue("NameServer");
     Console.WriteLine("DNS Servers: {0}", serverlist);
     DNSserverKey.Close();
     start.Close();
     char[] token = new char[1];
     token[0] = " ";
     string[] servers = serverlist.Split(token);
     foreach(string server in servers)
     {
        Console.WriteLine("DNS server: {0}", server);
     }
  }

}</source>