We Keep Coding

How to retrieve the onboard ethernet MAC address of a computer?

I am trying to retrieve the MAC address for the onboard ethernet adapter from a computer, in order to generate a unique identifier for the device. Below is the approach I am using.
NetworkInterface[] ifConfig = NetworkInterface.GetAllNetworkInterfaces();
int maxHash = int.MinValue;
Guid D = Guid.Empty;
foreach (NetworkInterface net in ifConfig)
{
if (net.NetworkInterfaceType == NetworkInterfaceType.Ethernet)
{
if (maxHash < net.GetPhysicalAddress().ToString().GetHashCode())
{
maxHash = net.GetPhysicalAddress().ToString().GetHashCode();
ID = new Guid(String.Concat("00000000-0000-0000-0000-", net.GetPhysicalAddress().ToString()));
}
}
}
However, the Bluetooth adapter, VM adapter and several other network adapters are also of the NetworkInterfaceType.Ethernet type. How can I specifically get the onboard ethernet connection's MAC address?
Doing a contains to omit those wouldn't be possible. Any help would be much appreciated.

I recently wrote a Powershell Script to generate a permanent system-format-immutable unique ID for a Windows PC for inventory purposes (QR encode the ID, print it on a sticker...).
It concatenates the PC manufacturer UUID field with the permanent MAC address of every PCI-connected network adapter (sorted alphabetically by MAC). The PCI requirement automatically dismisses removable or virtual NICs. The real script MD5-hashes the resulting string in order to obtain a more homogeneous identifier (constant length and 0-9A-F set of symbols), but I will omit this here for the sake of simplicity
I could’ve settled for the PC manufacturer UUID and call it a day, but I didn’t feel comfortable with an ID that relies on:
Each PC manufacturer in the world making the effort of filling in the UUID BIOS field.
Every PC manufacturer making the effort of keeping track of already used UUIDs
Basically, I tried to adhere to the intuitive idea of putting in the mixer as many non-removable components with permanent and “unique” (dream on) identifier as possible.
This ID generation technique is not fail proof: if a new PCI network adapter is added to the system, the ID will change. But with the popularization of integrated NICs I believe this is no longer something to worry about, if it ever was.
This solution is not directly applicable for C#, but I believe it can be easily adapted since Powershell shares almost the same .net object-class ecosystem.
#Variable names in spanish, but if I try to translate them in a hurry
#I will most certainly end up with a non-working script
$elpc=(Get-WmiObject -Class Win32_ComputerSystemProduct)
$id=$elpc.UUID #This is the UUID the manufacturer wrote somewhere in the BIOS
#Get network devices
#"Net" for network devices, "PCI*" because PCI connected devices begin that way
$dispositivosdered=#(Get-PnpDevice | Where-Object {($_.Class -eq "Net") -and ($_.InstanceId -like "PCI*")})
#Get network adapters
#Use "PermanentAddress" property. "MacAddress" property can be spoofed easily
$tarjetasdered=#(Get-Netadapter | Sort-Object PermanentAddress)
#Double loop to rule out any network adapters which are not PCI
#Comparison is made using long name, ie "Realtek PCIe GBE Family Controller #2"
#Is the only valid field I found to (inner) join the device and adapter worlds
for($j=0; $j -lt $tarjetasdered.length; $j++) {
for ($i=0; $i -lt $dispositivosdered.length; $i++) {
if($dispositivosdered[$i].FriendlyName -eq $tarjetasdered[$j].InterfaceDescription) {
if(-not [string]::IsNullOrEmpty($tarjetasdered[$j].PermanentAddress)) {
$id= $id + $tarjetasdered[$j].PermanentAddress.Replace("-", "");
}
}
}
}

As an option (not the best, but still =) ) - You can try to use
metric. In most cases the metric of the network to a physical network
card priority
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Management;
using System.Net.NetworkInformation;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
private void button1_Click(object sender, EventArgs e)
{
listBox1.Items.Clear();
ManagementObjectSearcher query = new
ManagementObjectSearcher("SELECT * FROM Win32_NetworkAdapterConfiguration WHERE IPEnabled = 'TRUE'");
ManagementObjectCollection queryCollection = query.Get();
foreach (ManagementObject mo in queryCollection)
{
if (!(mo["Description"].ToString().Contains("VM")))
{
if (!(mo["Description"].ToString().Contains("Virtual")))
{
if (!(mo["Description"].ToString().Contains("Hyper")))
{
string[] addresses = (string[])mo["IPAddress"];
string IPConnectionMetric = Convert.ToString(mo["IPConnectionMetric"]).Trim();
foreach (string ipaddress in addresses)
{
listBox1.Items.Add(ipaddress + ";" + IPConnectionMetric);
}
}
private void button2_Click(object sender, EventArgs e)
{
if (listBox1.Items.Count > 1)
{
int maximum = int.MinValue;
int minimum = int.MaxValue;
for (int i = 0; i < listBox1.Items.Count; i++)
{
int output = Convert.ToInt32(listBox1.Items[i].ToString().Split(';')[1]);
if ((int)output > maximum)
maximum = (int)output;
}
for (int i = 0; i < listBox1.Items.Count; i++)
{
int output = Convert.ToInt32(listBox1.Items[i].ToString().Split(';')[1]);
if ((int)output < maximum)
minimum = (int)output;
if (listBox1.Items[i].ToString().Contains(minimum.ToString()))
{
var minmetric = listBox1.Items[i].ToString();
NetworkInterface[] ifConfig = NetworkInterface.GetAllNetworkInterfaces();
int maxHash = int.MinValue;
Guid D = Guid.Empty;
foreach (NetworkInterface net in ifConfig)
{
if (net.NetworkInterfaceType == NetworkInterfaceType.Ethernet)
{
if (maxHash < net.GetPhysicalAddress().ToString().GetHashCode())
{
maxHash = net.GetPhysicalAddress().ToString().GetHashCode();
foreach (UnicastIPAddressInformation ip in net.GetIPProperties().UnicastAddresses)
{
if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
{
if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
{
if (ip.Address.ToString().Contains(minmetric.ToString().Split(';')[0]))
{
var ID = new Guid(String.Concat("00000000-0000-0000-0000-", net.GetPhysicalAddress().ToString()));
}
}
else
{
NetworkInterface[] ifConfig = NetworkInterface.GetAllNetworkInterfaces();
int maxHash = int.MinValue;
Guid D = Guid.Empty;
foreach (NetworkInterface net in ifConfig)
{
if (net.NetworkInterfaceType == NetworkInterfaceType.Ethernet)
{
if (maxHash < net.GetPhysicalAddress().ToString().GetHashCode())
{
maxHash = net.GetPhysicalAddress().ToString().GetHashCode();
var ID = new Guid(String.Concat("00000000-0000-0000-0000-", net.GetPhysicalAddress().ToString()));
}
}
}

using system.Management;
private string GetMACAddress()
{
ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection moc = mc.GetInstances();
string MACAddress = String.Empty;
foreach (ManagementObject mo in moc)
{
if (MACAddress == String.Empty) // only return MAC Address from first card
{
if ((bool)mo["IPEnabled"] == true) MACAddress = mo["MacAddress"].ToString();
}
mo.Dispose();
}
MACAddress = MACAddress.Replace(":", "");
return MACAddress;
}

How to Change Public IP Address in C#

I am creating a C# winform application, in which I want to change the Public IP Address, NOT the IPv4 Address like (Hotspot-Shield, ZenMate, OpenVPN, and others do).
I have checked the following links but didn't find enough help, so I am posting this question:
How can you change Network settings (IP Address, DNS, WINS, Host Name) with code in C#
Changing IP address in C#
I write the same code as in the answer of 1st link and also used the libraries but when I check my IP address through google.com it remains the same. I don't know the socket programming.
Here is my code:
namespace WindowsFormsApplication1
{
class ChangeIP
{
public void SetIP(string ipAddress, string subnetMask, string gateway)
{
using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
{
using (var networkConfigs = networkConfigMng.GetInstances())
{
foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(managementObject => (bool)managementObject["IPEnabled"]))
{
using (var newIP = managementObject.GetMethodParameters("EnableStatic"))
{
// Set new IP address and subnet if needed
if ((!String.IsNullOrEmpty(ipAddress)) || (!String.IsNullOrEmpty(subnetMask)))
{
if (!String.IsNullOrEmpty(ipAddress))
{
newIP["IPAddress"] = new[] { ipAddress };
}
if (!String.IsNullOrEmpty(subnetMask))
{
newIP["SubnetMask"] = new[] { subnetMask };
}
managementObject.InvokeMethod("EnableStatic", newIP, null);
}
// Set mew gateway if needed
if (!String.IsNullOrEmpty(gateway))
{
using (var newGateway = managementObject.GetMethodParameters("SetGateways"))
{
newGateway["DefaultIPGateway"] = new[] { gateway };
newGateway["GatewayCostMetric"] = new[] { 1 };
managementObject.InvokeMethod("SetGateways", newGateway, null);
}
}
}
}
}
}
}
/// <summary>
/// Set's the DNS Server of the local machine
/// </summary>
/// <param name="nic">NIC address</param>
/// <param name="dnsServers">Comma seperated list of DNS server addresses</param>
/// <remarks>Requires a reference to the System.Management namespace</remarks>
public void SetNameservers(string nic, string dnsServers)
{
using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
{
using (var networkConfigs = networkConfigMng.GetInstances())
{
foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(objMO => (bool)objMO["IPEnabled"] && objMO["Caption"].Equals(nic)))
{
using (var newDNS = managementObject.GetMethodParameters("SetDNSServerSearchOrder"))
{
newDNS["DNSServerSearchOrder"] = dnsServers.Split(',');
managementObject.InvokeMethod("SetDNSServerSearchOrder", newDNS, null);
}
}
}
}
}
}
}
And Here is how I am calling those methods:
{
static string local_ip;
string public_ip;
public static string GetLocalIPAddress() //Method For Getting Local Machine IP
{
var host = Dns.GetHostEntry(Dns.GetHostName());
foreach (var ip in host.AddressList)
{
if (ip.AddressFamily == AddressFamily.InterNetwork)
{
return ip.ToString();
}
}
throw new Exception("Local IP Address Not Found!");
}
// Mehod End
local_ip = GetLocalIPAddress();
ChangeIP ip = new ChangeIP();
ip.SetIP(local_ip, null, null); // Calling Method
var getNIC = NetworkInterface.GetAllNetworkInterfaces();
NetworkInterface[] NI = NetworkInterface.GetAllNetworkInterfaces();
string nic = string.Empty;
string dnsServer = string.Empty;
foreach(var r in getNIC)
{
nic = r.Name;
}
foreach(NetworkInterface ninter in NI)
{
if(ninter.OperationalStatus == OperationalStatus.Up)
{
IPInterfaceProperties ipProperties = ninter.GetIPProperties();
IPAddressCollection dnsAddresses = ipProperties.DnsAddresses;
foreach(IPAddress dnsAdrs in dnsAddresses)
{
dnsServer = dnsAdrs.ToString();
}
}
}
ip.SetNameservers(nic, dnsServer); // Calling Method
public_ip = new WebClient().DownloadString("http://icanhazip.com");
}

How you've described your question is not how the internet (is supposed to) work(s).
Windows doesn't let you write raw IP packets, for this you need to use a TAP/TUN driver. But although you send out packets spoofing the source IP address, the internet between you and the destination won't return the route.
If you're operating behind a block of IP addresses, and only want to spoof another in that block, the return address will get back to your local router, but still won't necessary route back to you.
Unless you use TAP/TUN, there's no other way to steal someone else's Public IP address, excluding other network security vulnerability exploitations which are beyond the scope of this forum.
And even with TAP/TUN you're very limited in what you can achieve over spoofed IP packets in one direction. In fact, ISPs may filter out spoofed IP addresses.

Determine which network adapter has the highest priority in C#?

If we have multiple network interfaces with the same DNS suffix on a given machine, how do I programatically determine which network interface traffic will be routed over?
For example, I am connected to my companies network via ethernet in office, and connected to the companies network via VPN from inside the office. This sounds stupid, but with the way our networks are connected, if the internal link to our datacenter goes down - I VPN from inside the office to continue development.
Our software has logic to determine our "local ip address" and uses that for authentication logic elsewhere. I know from practice that all my traffic is routed over the VPN when connected - but am struggling with what the correct implementation in code is for robustly choosing the IP address of the adapter with the highest priority.
What I have right now is:
var unicastIpAddressInformation = NetworkInterface.GetAllNetworkInterfaces()
.Where(nic => nic.OperationalStatus == OperationalStatus.Up
&& nic.NetworkInterfaceType != NetworkInterfaceType.Loopback // ...ignore the loopback NIC as we don't want 127.0.0.1 (1 of 2)
&& nic.Name.IndexOf("loopback", StringComparison.OrdinalIgnoreCase) == -1 // ...ignore the loopback NIC as we don't want 127.0.0.1 (2 of 2)
&& nic.Name.IndexOf("virtual", StringComparison.OrdinalIgnoreCase) == -1 // ... ignore virtual NICs so that VMs don't conflict with IP resolution
)
.Select(n => n.GetIPProperties())
// All developer network connections should have the my-company-internal.com suffix
.Where(ipp => ipp.DnsSuffix.ToLowerInvariant().IndexOf("my-company-internal.com", StringComparison.OrdinalIgnoreCase) >= 0)
.Where(ipp => ipp.UnicastAddresses.Any(u => u.Address.AddressFamily == AddressFamily.InterNetwork))
// Is this order by correct?
.OrderByDescending(ipp => ipp.GetIPv4Properties().Index)
.SelectMany(ipp => ipp.UnicastAddresses.Where(ip => ip.Address.AddressFamily == AddressFamily.InterNetwork))
.FirstOrDefault();
I know with the IPV4Properties.Index - it is only populated when IPv4 is enabled; I don't know if corresponds to priority or metric, and whether or not they are guaranteed to be distinct.

I had the same problem here a few weeks ago. I figured out that the NIC priority is persisted in Windows Registry, and there are a few PowerShell scripts that can give you the NIC order, but not the IP addresses. So, I've written the code below and it worked for me. You can use it to see additional info like dns suffix, gateway address and plus.
You just have to call RMSNetUtils.GetTopIpv4Ip(string.Empty)
public class RMSNetUtils
{
private static string _linkagePath = #"SYSTEM\CurrentControlSet\Services\Tcpip\Linkage";
private static string _interfacesPath = #"SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\";
private static List<string> GetBindingsPriority()
{
using (var bindMasterKey = Registry.LocalMachine.OpenSubKey(_linkagePath))
{
var bind = (string[]) bindMasterKey.GetValue("Bind");
var deviceList = bind.Select(x => $#"{_interfacesPath}{x.Replace("\\Device\\", string.Empty)}")
.ToList();
var result = new List<string>();
foreach (var device in deviceList)
{
using (var bindKey = Registry.LocalMachine.OpenSubKey(device))
{
var fixIP = (string[])bindKey.GetValue("IPAddress");
if (fixIP != null)
{
result.Add( fixIP.FirstOrDefault());
continue;
}
var dhcpIp = bindKey.GetValue("DhcpIPAddress");
if (dhcpIp != null)
{
result.Add((string) dhcpIp);
}
}
}
return result;
}
}
private static List<NICInformation> GetFilteredBindings()
{
var bindings = GetBindingsPriority();
var nicsInfo = GetIpList(GetInterNetworkAdapters());
var result = new List<NICInformation>();
foreach (var bind in bindings)
{
var nicInfo = nicsInfo.FirstOrDefault(y => string.Compare(y.IPv4, bind) == 0);
if(nicInfo!= null)
result.Add(nicInfo);
}
return result;
}
private static IEnumerable<IPAddress> GetInterNetworkAdapters()
{
IPHostEntry local = Dns.GetHostEntry(string.Empty);
return (from ipa in local.AddressList
where ipa.AddressFamily == AddressFamily.InterNetwork
select ipa);
}
public static string GetFirstIpv4Ip()
{
return GetFirstIpv4Ip(String.Empty);
}
private static List<NICInformation> GetIpList(IEnumerable<IPAddress> ips)
{
var ipAddresses = ips.Select(x => x.ToString()).ToList();
var result = new List<NICInformation>();
foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
{
if (ni.NetworkInterfaceType == NetworkInterfaceType.Wireless80211 ||
ni.NetworkInterfaceType == NetworkInterfaceType.Ethernet)
{
foreach (UnicastIPAddressInformation ip in ni.GetIPProperties().UnicastAddresses)
{
if (ip.Address.AddressFamily == AddressFamily.InterNetwork)
{
var ipStr = ip.Address.ToString();
if (ipAddresses.Contains(ipStr))
{
var nic = new NICInformation();
nic.IPv4 = ip.Address.ToString();
nic.Mask = ip.IPv4Mask.ToString();
nic.DnsSuffix = ni.GetIPProperties().DnsSuffix;
var gateway = ni.GetIPProperties().GatewayAddresses.FirstOrDefault();
if(gateway!=null)
nic.Gateway = gateway.Address.ToString();
result.Add(nic);
}
}
}
}
}
return result;
}
public static string GetTopIpv4Ip(string hostName)
{
if (!string.IsNullOrEmpty(hostName))
return GetFirstIpv4Ip(hostName);
var item = GetFilteredBindings().FirstOrDefault();
return item == null ? hostName : item.IPv4;
}
public static string GetFirstIpv4Ip(string hostName)
{
var ip = string.Empty;
try
{
IPHostEntry local = Dns.GetHostEntry(hostName);
var result = GetInterNetworkAdapters().FirstOrDefault();
return result != null ? result.ToString() : hostName;
}
catch (SocketException ex)
{
ip = hostName;
}
return ip;
}
}
public class NICInformation
{
public string DnsSuffix {get;set;}
public string IPv4 {get;set; }
public string Gateway {get;set;}
public string Mask {get;set;}
}

How to obtain Public IP of a device using C# with out using external API/Services

public static string GetPublicIp()
{
HttpContext context = HttpContext.Current;
string ipAddress = context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (!string.IsNullOrEmpty(ipAddress))
{
string[] addresses = ipAddress.Split(',');
if (addresses.Length != 0)
{
return addresses[0];
}
}
return context.Request.ServerVariables["REMOTE_ADDR"];
}
I'm trying to get the client Public IP but the above code only returns the client Local IP. If different people are connecting to my organisation from the same organisations network, i want to get only their public IP address. I'm not intrested in their local IPs, is this possible.
Below is one solution i have so far seen but i'm NOT liking it.
public static string GetPublicIp()
{
string direction = "";
WebRequest request = WebRequest.Create("http://checkip.dyndns.org");
using (WebResponse response1 = request.GetResponse())
using (StreamReader stream1 = new StreamReader(response1.GetResponseStream()))
{
direction = stream1.ReadToEnd();
}
//Search for the ip in the html
int first1 = direction.IndexOf("Address: ") + 9;
int last1 = direction.LastIndexOf("</body>");
direction = direction.Substring(first1, last1 - first1);
return direction;
}
The above sample solution can get me the public IP but i don't want to be tied to an external service that i have no control over because if that service is down then iam screwed and the performance is terrible.
Does any one know how i can get the clients public IP with out calling external services?

This method gives you the local ip address. I've copied it from a WinRT-Solution, maybe the class names are a bit different in other .NET environments.
private static string GetLocalAddress()
{
var hostnames = NetworkInformation.GetHostNames();
foreach (var hn in hostnames)
{
//IanaInterfaceType == 71 => Wifi
//IanaInterfaceType == 6 => Ethernet (Emulator)
if (hn.IPInformation != null &&
(hn.IPInformation.NetworkAdapter.IanaInterfaceType == 71
|| hn.IPInformation.NetworkAdapter.IanaInterfaceType == 6))
{
return hn.DisplayName;
}
}
return IpAddress.Broadcast.Address;
}
EDIT: The following method prints out all local ip addresses.
private static void PrintLocalAddresses()
{
var interfaces = NetworkInterface.GetAllNetworkInterfaces();
foreach (var ni in interfaces)
{
if (ni.NetworkInterfaceType == NetworkInterfaceType.Ethernet ||
ni.NetworkInterfaceType == NetworkInterfaceType.Wireless80211)
{
var adapterProperties = ni.GetIPProperties();
foreach (var x in adapterProperties.UnicastAddresses)
{
if (x.Address.AddressFamily == AddressFamily.InterNetwork)
{
Console.WriteLine(x.Address);
}
}
}
}
}

How to get IPv4 and IPv6 address of local machine?

I am developing a windows application and I need to find the IPv4 and IPv6 address of local machine. OS can be XP or Windows 7.
I got a solution for getting MAC address like,
string GetMACAddress()
{
var macAddr =
(
from nic in NetworkInterface.GetAllNetworkInterfaces()
where nic.OperationalStatus == OperationalStatus.Up
select nic.GetPhysicalAddress().ToString()
).FirstOrDefault();
return macAddr.ToString();
}
This is working in all OS.
What is the correct way to get IPv4 and IPv6 address that work on XP and WINDOWS 7?

string strHostName = System.Net.Dns.GetHostName();;
IPHostEntry ipEntry = System.Net.Dns.GetHostEntry(strHostName);
IPAddress[] addr = ipEntry.AddressList;
Console.WriteLine(addr[addr.Length-1].ToString());
if (addr[0].AddressFamily == System.Net.Sockets.AddressFamily.InterNetworkV6)
{
Console.WriteLine(addr[0].ToString()); //ipv6
}

To get all IP4 and IP6 address, here is my preferred solution. Note that it also filters the loopback IP addresses like 127.0.0.1 or ::1
public static IEnumerable<IPAddress> GetIpAddress()
{
var host = Dns.GetHostEntry(Dns.GetHostName());
return (from ip in host.AddressList where !IPAddress.IsLoopback(ip) select ip).ToList();
}

Here's my method for getting all the IPv4 addresses only.
/// <summary>
/// Gets/Sets the IPAddress(s) of the computer which the client is running on.
/// If this isn't set then all IPAddresses which could be enumerated will be sent as
/// a comma separated list.
/// </summary>
public string IPAddress
{
set
{
_IPAddress = value;
}
get
{
string retVal = _IPAddress;
// If IPAddress isn't explicitly set then we enumerate all IP's on this machine.
if (_IPAddress == null)
{
// TODO: Only return ipaddresses that are for Ethernet Adapters
String strHostName = Dns.GetHostName();
IPHostEntry ipEntry = Dns.GetHostEntry(strHostName);
IPAddress[] addr = ipEntry.AddressList;
List<string> validAddresses = new List<string>();
// Loops through the addresses and creates a list of valid ones.
for (int i = 0; i < addr.Length; i++)
{
string currAddr = addr[i].ToString();
if( IsValidIP( currAddr ) ) {
validAddresses.Add( currAddr );
}
}
for(int i=0; i<validAddresses.Count; i++)
{
retVal += validAddresses[i];
if (i < validAddresses.Count - 1)
{
retVal += ",";
}
}
if (String.IsNullOrEmpty(retVal))
{
retVal = String.Empty;
}
}
return retVal;
}
}