Get local IP address

Question

In the internet there are several places that show you how to get an IP address  And a lot of them look like this example   String strHostName   string Empty     Getting Ip address of local machine       First get the host name of local machine  strHostName   Dns GetHostName    Console WriteLine  Local Machine s Host Name      strHostName      Then using host name  get the IP address list   IPHostEntry ipEntry   Dns GetHostEntry strHostName   IPAddress   addr   ipEntry AddressList   for  int i   0  i  lt  addr Length  i          Console WriteLine  IP Address  0    1     i  addr i  ToString       Console ReadLine      With this example I get several IP addresses  but I m only interested in getting the one that the router assigns to the computer running the program  the IP that I would give to someone if he wishes to access a shared folder in my computer for instance   If I am not connected to a network and I am connected to the internet directly via a modem with no router then I would like to get an error  How can I see if my computer is connected to a network with C  and if it is then to get the LAN IP address

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Tested with one or multiple LAN cards and Virtual machines  public static string DisplayIPAddresses                 string returnAddress   String Empty              Get a list of all network interfaces  usually one per network card  dialup  and VPN connection          NetworkInterface   networkInterfaces   NetworkInterface GetAllNetworkInterfaces             foreach  NetworkInterface network in networkInterfaces                           Read the IP configuration for each network             IPInterfaceProperties properties   network GetIPProperties                 if  network NetworkInterfaceType    NetworkInterfaceType Ethernet  amp  amp                     network OperationalStatus    OperationalStatus Up  amp  amp                      network Description ToLower   Contains  virtual    amp  amp                      network Description ToLower   Contains  pseudo                                     Each network interface may have multiple IP addresses                 foreach  IPAddressInformation address in properties UnicastAddresses                                           We re only interested in IPv4 addresses for now                     if  address Address AddressFamily    AddressFamily InterNetwork                          continue                          Ignore loopback addresses  e g   127 0 0 1                      if  IPAddress IsLoopback address Address                           continue                       returnAddress   address Address ToString                        Console WriteLine address Address ToString            network Name     -     network Description                                                           return returnAddress

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Pre requisites  you have to add System Data Linq reference and refer it  using System Linq  string ipAddress      IPHostEntry ipHostInfo   Dns GetHostEntry Dns GetHostName     ipAddress   Convert ToString ipHostInfo AddressList FirstOrDefault address   gt  address AddressFamily    AddressFamily InterNetwork

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There is a more accurate way when there are multi ip addresses available on local machine  Connect a UDP socket and read its local endpoint   string localIP  using  Socket socket   new Socket AddressFamily InterNetwork  SocketType Dgram  0         socket Connect  8 8 8 8   65530       IPEndPoint endPoint   socket LocalEndPoint as IPEndPoint      localIP   endPoint Address ToString        Connect on a UDP socket has the following effect  it sets the destination for Send Recv  discards all packets from other addresses  and - which is what we use - transfers the socket into  connected  state  settings its appropriate fields  This includes checking the existence of the route to the destination according to the system s routing table and setting the local endpoint accordingly  The last part seems to be undocumented officially but it looks like an integral trait of Berkeley sockets API  a side effect of UDP  connected  state  that works reliably in both Windows and Linux across versions and distributions   So  this method will give the local address that would be used to connect to the specified remote host  There is no real connection established  hence the specified remote ip can be unreachable

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Just an updated version of mine using LINQ        lt summary gt      Gets the local Ipv4       lt  summary gt       lt returns gt The local Ipv4  lt  returns gt       lt param name  networkInterfaceType  gt Network interface type  lt  param gt  IPAddress GetLocalIPv4 NetworkInterfaceType networkInterfaceType        var networkInterfaces   NetworkInterface GetAllNetworkInterfaces   Where i   gt  i NetworkInterfaceType    networkInterfaceType  amp  amp  i OperationalStatus    OperationalStatus Up        foreach  var networkInterface in networkInterfaces                var adapterProperties   networkInterface GetIPProperties             if  adapterProperties GatewayAddresses FirstOrDefault      null                  continue          foreach  var ip in networkInterface GetIPProperties   UnicastAddresses                        if  ip Address AddressFamily    AddressFamily InterNetwork                      continue               return ip Address                       return null

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This returns addresses from any interfaces that have gateway addresses and unicast addresses in two separate lists  IPV4 and IPV6   public static  List lt IPAddress gt  V4  List lt IPAddress gt  V6  GetLocal         List lt IPAddress gt  foundV4   new List lt IPAddress gt         List lt IPAddress gt  foundV6   new List lt IPAddress gt          NetworkInterface GetAllNetworkInterfaces   ToList   ForEach ni   gt                if  ni GetIPProperties   GatewayAddresses FirstOrDefault      null                        ni GetIPProperties   UnicastAddresses ToList   ForEach ua   gt                                if  ua Address AddressFamily    AddressFamily InterNetwork  foundV4 Add ua Address                   if  ua Address AddressFamily    AddressFamily InterNetworkV6  foundV6 Add ua Address                                          return  foundV4 Distinct   ToList    foundV6 Distinct   ToList

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To get local Ip Address   public static string GetLocalIPAddress         var host   Dns GetHostEntry Dns GetHostName         foreach  var ip in host AddressList                if  ip AddressFamily    AddressFamily InterNetwork                        return ip ToString                        throw new Exception  No network adapters with an IPv4 address in the system         To check if you re connected or not   System Net NetworkInformation NetworkInterface GetIsNetworkAvailable

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Updating Mrchief s answer with Linq  we will have   public static IPAddress GetLocalIPAddress        var host   Dns GetHostEntry Dns GetHostName        var ipAddress  host AddressList FirstOrDefault ip   gt  ip AddressFamily    AddressFamily InterNetwork      return ipAddress

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string str      System Net Dns GetHostName     IPHostEntry ipEntry   System Net Dns GetHostEntry str    IPAddress   addr   ipEntry AddressList   string IP  Your Ip Address Is  - gt    addr addr Length - 1  ToString

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There is already many of answer  but I m still contributing mine one   public static IPAddress LocalIpAddress         Func lt IPAddress  bool gt  localIpPredicate   ip   gt          ip AddressFamily    AddressFamily InterNetwork  amp  amp          ip ToString   StartsWith  192 168      check only for 16-bit block     return Dns GetHostEntry Dns GetHostName    AddressList LastOrDefault localIpPredicate       One liner   public static IPAddress LocalIpAddress     gt  Dns GetHostEntry Dns GetHostName    AddressList LastOrDefault ip   gt  ip AddressFamily    AddressFamily InterNetwork  amp  amp  ip ToString   StartsWith  192 168       note  Search from last because it still worked after some interfaces added into device  such as MobileHotspot VPN or other fancy virtual adapters

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In addition just simple code for getting Client Ip           public static string getclientIP                         var HostIP   HttpContext Current    null   HttpContext Current Request UserHostAddress                   return HostIP              Hope it s help you

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Imports System Net Imports System Net Sockets Function LocalIP       Dim strHostName   Dns GetHostName     Dim Host   Dns GetHostEntry strHostName      For Each ip In Host AddressList         If ip AddressFamily   AddressFamily InterNetwork Then             txtIP Text   ip ToString         End If     Next      Return True End Function  Below same action Function LocalIP       Dim Host As String  Dns GetHostEntry Dns GetHostName  AddressList 1  MapToIPv4 ToString     txtIP Text   Host     Return True  End Function

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Using these  using System Net  using System Net Sockets  using System Net NetworkInformation  using System Linq   You can use a series of LINQ methods to grab the most preferred IP address  public static bool IsIPv4 IPAddress ipa    gt  ipa AddressFamily    AddressFamily InterNetwork   public static IPAddress GetMainIPv4     gt  NetworkInterface GetAllNetworkInterfaces    Select  ni   gt ni GetIPProperties     Where  ip   gt  ip GatewayAddresses Where  ga    gt  IsIPv4 ga Address   Count    gt  0   FirstOrDefault    UnicastAddresses   Where  ua    gt  IsIPv4 ua Address    FirstOrDefault    Address   This simply finds the first Network Interface that has an IPv4 Default Gateway  and gets the first IPv4 address on that interface  Networking stacks are designed to have only one Default Gateway  and therefore the one with a Default Gateway  is the best one  WARNING  If you have an abnormal setup where the main adapter has more than one IPv4 Address  this will grab only the first one   The solution to grabbing the best one in that scenario involves grabbing the Gateway IP  and checking to see which Unicast IP is in the same subnet as the Gateway IP Address  which would kill our ability to create a pretty LINQ method based solution  as well as being a LOT more code

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Here is a modified version  from compman2408 s one  which worked for me       internal static string GetLocalIPv4 NetworkInterfaceType  type            Checks your IP adress from the local network connected to a gateway  This to avoid issues with double network cards         string output           default output         foreach  NetworkInterface item in NetworkInterface GetAllNetworkInterfaces       Iterate over each network interface               Find the network interface which has been provided in the arguments  break the loop if found             if  item NetworkInterfaceType     type  amp  amp  item OperationalStatus    OperationalStatus Up                     Fetch the properties of this adapter                 IPInterfaceProperties adapterProperties   item GetIPProperties                       Check if the gateway adress exist  if not its most likley a virtual network or smth                 if  adapterProperties GatewayAddresses FirstOrDefault      null                         Iterate over each available unicast adresses                     foreach  UnicastIPAddressInformation ip in adapterProperties UnicastAddresses                             If the IP is a local IPv4 adress                         if  ip Address AddressFamily    System Net Sockets AddressFamily InterNetwork                                 we got a match                              output   ip Address ToString                                break      break the loop                                                                                                  Check if we got a result if so break this method             if  output          break                         Return results         return output          You can call this method for example like    GetLocalIPv4 NetworkInterfaceType Ethernet     The change  I m retrieving the IP from an adapter which has a gateway IP assigned to it  Second change  I ve added docstrings and break statement to make this method more efficient

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I think using LINQ is easier  Dns GetHostEntry Dns GetHostName        AddressList     First x   gt  x AddressFamily    System Net Sockets AddressFamily InterNetwork      ToString

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Other way to get IP using linq expression   public static List lt string gt  GetAllLocalIPv4 NetworkInterfaceType type        return NetworkInterface GetAllNetworkInterfaces                       Where x   gt  x NetworkInterfaceType    type  amp  amp  x OperationalStatus    OperationalStatus Up                      SelectMany x   gt  x GetIPProperties   UnicastAddresses                      Where x   gt  x Address AddressFamily    AddressFamily InterNetwork                      Select x   gt  x Address ToString                        ToList

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mrcheif I found this answer today and it was very useful although it did return a wrong IP  not due to the code not working  but it gave the wrong internetwork IP when you have such things as Himachi running   public static string localIPAddress         IPHostEntry host      string localIP           host   Dns GetHostEntry Dns GetHostName          foreach  IPAddress ip in host AddressList                localIP   ip ToString             string   temp   localIP Split                if  ip AddressFamily    AddressFamily InterNetwork  amp  amp  temp 0      192                         break                    else                       localIP   null                       return localIP

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Keep in mind  in the general case you could have multiple NAT translations going on  and multiple dns servers  each operating on different NAT translation levels   What if you have carrier grade NAT  and want to communicate with other customers of the same carrier  In the general case you never know for sure because you might appear with different host names at every NAT translation

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I also was struggling with obtaining the correct IP    I tried a variety of the solutions here but none provided me the desired affect  Almost all of the conditional tests that was provided caused no address to be used   This is what worked for me  hope it helps     var firstAddress    from address in NetworkInterface GetAllNetworkInterfaces   Select x   gt  x GetIPProperties    SelectMany x   gt  x UnicastAddresses  Select x   gt  x Address                      where  IPAddress IsLoopback address   amp  amp  address AddressFamily    System Net Sockets AddressFamily InterNetwork                     select address  FirstOrDefault     Console WriteLine firstAddress

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Dns GetHostEntry Dns GetHostName    AddressList 1  MapToIPv4     returns 192 168 14 1

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This is the best code I found to get the current IP  avoiding get VMWare host or other invalid IP address   public string GetLocalIpAddress         UnicastIPAddressInformation mostSuitableIp   null       var networkInterfaces   NetworkInterface GetAllNetworkInterfaces         foreach  var network in networkInterfaces                if  network OperationalStatus    OperationalStatus Up              continue           var properties   network GetIPProperties             if  properties GatewayAddresses Count    0              continue           foreach  var address in properties UnicastAddresses                        if  address Address AddressFamily    AddressFamily InterNetwork                  continue               if  IPAddress IsLoopback address Address                   continue               if   address IsDnsEligible                                if  mostSuitableIp    null                      mostSuitableIp   address                  continue                                The best IP is the IP got from DHCP server             if  address PrefixOrigin    PrefixOrigin Dhcp                                if  mostSuitableIp    null     mostSuitableIp IsDnsEligible                      mostSuitableIp   address                  continue                             return address Address ToString                         return mostSuitableIp    null            mostSuitableIp Address ToString

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For a laugh  thought I d try and get a single LINQ statement by using the new C  6 null-conditional operator  Looks pretty crazy and probably horribly inefficient  but it works   private string GetLocalIPv4 NetworkInterfaceType type   NetworkInterfaceType Ethernet           Bastardized from  http   stackoverflow com a 28621250 2685650       return NetworkInterface          GetAllNetworkInterfaces            FirstOrDefault ni   gt              ni NetworkInterfaceType    type              amp  amp  ni OperationalStatus    OperationalStatus Up              amp  amp  ni GetIPProperties   GatewayAddresses FirstOrDefault      null              amp  amp  ni GetIPProperties   UnicastAddresses FirstOrDefault ip   gt  ip Address AddressFamily    AddressFamily InterNetwork     null                     GetIPProperties            UnicastAddresses          FirstOrDefault ip   gt  ip Address AddressFamily    AddressFamily InterNetwork            Address           ToString              string Empty      Logic courtesy of Gerardo H  and by reference compman2408

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Obsolete gone  this works to me  public static IPAddress GetIPAddress       IPAddress ip   Dns GetHostAddresses Dns GetHostName    Where address   gt    address AddressFamily    AddressFamily InterNetwork  First     return ip

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Refactoring Mrcheif s code to leverage Linq  ie   Net 3 0       private IPAddress LocalIPAddress         if   System Net NetworkInformation NetworkInterface GetIsNetworkAvailable                  return null             IPHostEntry host   Dns GetHostEntry Dns GetHostName          return host          AddressList          FirstOrDefault ip   gt  ip AddressFamily    AddressFamily InterNetwork

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Modified compman2408 s code to be able to iterate through each NetworkInterfaceType   public static string GetLocalIPv4  NetworkInterfaceType  type        string output   null      foreach  NetworkInterface item in NetworkInterface GetAllNetworkInterfaces               if  item NetworkInterfaceType     type  amp  amp  item OperationalStatus    OperationalStatus Up                foreach  UnicastIPAddressInformation ip in item GetIPProperties    UnicastAddresses                    if  ip Address AddressFamily    AddressFamily InterNetwork                        output   ip Address ToString                                                         return output      And you can call it like so   static void Main  string   args           Get all possible enum values      var nitVals   Enum GetValues  typeof  NetworkInterfaceType   Cast lt NetworkInterfaceType gt           foreach  var nitVal in nitVals            Console WriteLine     nitVal    gt   GetLocalIPv4  nitVal      NULL

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I know this may be kicking a dead horse  but maybe this can help someone  I have looked all over the place for a way to find my local IP address  but everywhere I find it says to use   Dns GetHostEntry Dns GetHostName       I don t like this at all because it just gets all the addresses assigned to your computer  If you have multiple network interfaces  which pretty much all computers do now-a-days  you have no idea which address goes with which network interface  After doing a bunch of research I created a function to use the NetworkInterface class and yank the information out of it  This way I can tell what type of interface it is  Ethernet  wireless  loopback  tunnel  etc    whether it is active or not  and SOOO much more   public string GetLocalIPv4 NetworkInterfaceType  type        string output           foreach  NetworkInterface item in NetworkInterface GetAllNetworkInterfaces                  if  item NetworkInterfaceType     type  amp  amp  item OperationalStatus    OperationalStatus Up                        foreach  UnicastIPAddressInformation ip in item GetIPProperties   UnicastAddresses                                if  ip Address AddressFamily    AddressFamily InterNetwork                                        output   ip Address ToString                                                        return output      Now to get the IPv4 address of your Ethernet network interface call   GetLocalIPv4 NetworkInterfaceType Ethernet     Or your Wireless interface   GetLocalIPv4 NetworkInterfaceType Wireless80211     If you try to get an IPv4 address for a wireless interface  but your computer doesn t have a wireless card installed it will just return an empty string  Same thing with the Ethernet interface   Hope this helps someone   -   EDIT   It was pointed out  thanks  NasBanov  that even though this function goes about extracting the IP address in a much better way than using Dns GetHostEntry Dns GetHostName    it doesn t do very well at supporting multiple interfaces of the same type or multiple IP addresses on a single interface  It will only return a single IP address when there may be multiple addresses assigned  To return ALL of these assigned addresses you could simply manipulate the original function to always return an array instead of a single string  For example   public static string   GetAllLocalIPv4 NetworkInterfaceType  type        List lt string gt  ipAddrList   new List lt string gt         foreach  NetworkInterface item in NetworkInterface GetAllNetworkInterfaces                  if  item NetworkInterfaceType     type  amp  amp  item OperationalStatus    OperationalStatus Up                        foreach  UnicastIPAddressInformation ip in item GetIPProperties   UnicastAddresses                                if  ip Address AddressFamily    AddressFamily InterNetwork                                        ipAddrList Add ip Address ToString                                                         return ipAddrList ToArray        Now this function will return ALL assigned addresses for a specific interface type  Now to get just a single string  you could use the  FirstOrDefault   extension to return the first item in the array or  if it s empty  return an empty string   GetLocalIPv4 NetworkInterfaceType Ethernet  FirstOrDefault

[c#] Get local IP address

Tested with one or multiple LAN cards and Virtual machines

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