Develop Reference

Obtained different MAC Addresses during offline and online?

I'm coding a part where the software need to obtain MAC Address of the current PC and found this solution which works for offline too:
https://stackoverflow.com/a/15784105/9641721
I obtained the same MAC Address using method 1 but somehow get different Addresses during offline vs online when using method 2, anyone can explain to me why? FYI my laptop only has one network card.
Method 2:
public static string GetMACAddress2()
{
NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
String sMacAddress = string.Empty;
foreach (NetworkInterface adapter in nics)
{
if (sMacAddress == String.Empty)// only return MAC Address from first card
{
sMacAddress = adapter.GetPhysicalAddress().ToString();
}
}
return sMacAddress;
}
My result:
Online:
Method1: C85B76FD53xx
Method2: 6A00E3D94Exx
Offline:
Method1: C85B76FD53xx
Method2: C85B76FD53xx
Thanks.

Unable to get the IP Address of network printer?

I need to find the IP address of the installed printers on my laptop. I move my laptop between different locations and networks. Each network has its own set of ip addresses. The laptop has different printers installed for each location with all connections being made wirelessly.
In using the below code (.net 4.0), the QueuePort.Name returns:
WSD-27e3f972-cdc7-459d-b0c1-20e8410fb1db.0032 and
192.168.1.12_1
Since these are network printers, I assume these have to resolve to a real IP Address??
Where am I going wrong? Or is there a better way? Any help is really appreciated.
IEnumerable<Printer> GetLocalPrinters()
{
EnumeratedPrintQueueTypes[] enumerationFlags = { EnumeratedPrintQueueTypes.Local, EnumeratedPrintQueueTypes.Connections };
LocalPrintServer printServer = new LocalPrintServer();
var x = printServer.GetPrintQueues(enumerationFlags).Select(y =>
new Printer
{
Fullname = y.FullName,
QueuePortName = y.QueuePort.Name,
Location = y.Location
})
.OrderBy( z => z.QueuePortName);
return x;
}

The portname is NOT the IP address. Sometimes they are the same text.
They answer appears to be here:
Determine the IP Address of a Printer in C#
Edited 31-Oct-2011:
Query the WMI for the printer port IP address.
using System;
using System.Management;
namespace WMI_example_01
{
class Program
{
static void Main(string[] args)
{
var scope = new ManagementScope(#"\\.\root\cimv2");
var query = new ObjectQuery("SELECT * FROM win32_tcpipprinterport");
var searcher = new ManagementObjectSearcher(scope, query);
var collection = searcher.Get();
foreach(var col in collection)
{
Console.WriteLine("Port name: {0}\tHostAddress: {1}", col["Name"], col"HostAddress"]);
}
}
}
}

The printing queue has a corresponding port that is handled by the port monitor.
There are different port monitors (not only standard monitors like TCPMON and WSD but also custom and vendor-specific), as far as I know, there is no universal way to deal with all kinds of them.
From the provided port name, I assume you are dealing with the WSD port. Here things become a bit tricky, I suggest you read my answer https://stackoverflow.com/a/63705944/4700228 for the solution.

How to get mac address of client in asp.net?

i want get mac address of my website visitor in asp.net
how can i do it?
this code get host mac address
ManagementClass objMC = new ManagementClass("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection objMOC = objMC.GetInstances();
foreach (ManagementObject objMO in objMOC)
{
if (!(bool)objMO["ipEnabled"])
continue;
string a = ((string)objMO["MACAddress"]);
}

You cannot get the MAC of your visitor because MAC addresses do not survive hops across different hosts like IP addresses do. At the most what you could get is the MAC of the switch closest to the server, and even in that case I 'm not sure it is technically possible from ASP.NET.

Get IP address from hostname in LAN

I found many samples on how to get a hostname by an IP address, how can I get the IP address of a host in the LAN?

Try this
public static void DoGetHostAddresses(string hostname)
{
IPAddress[] ips;
ips = Dns.GetHostAddresses(hostname);
Console.WriteLine("GetHostAddresses({0}) returns:", hostname);
foreach (IPAddress ip in ips)
{
Console.WriteLine(" {0}", ip);
}
}
i got this from http://msdn.microsoft.com/en-us/library/system.net.dns.gethostaddresses.aspx

Here is simple code if you want to get the IP Address(V4) from your pc.
Import this library into your class
using System.Net;
Initialize and declare these variables into your codes. They contain hostname, ipaddress and an array of Host Addresses:
string HostName = Dns.GetHostName().ToString();
IPAddress[] IpInHostAddress = Dns.GetHostAddresses(HostName);
string IPV4Address = IpInHostAddress[1].ToString(); //Default IPV4Address. This might be the ip address you need to retrieve
string IPV6Address = IpInHostAddress[0].ToString(); //Default Link local IPv6 Address
Open your command prompt, just type "ipconfig" and press enter.Once you are done, you could check if the string IPV4Address matches to IPv4Address in our pc.

As long as you know the name of a machine, you can use Dns.GetHostAddresses. Your network DNS should recognize it as LAN computer and return proper IP.

Use Dns.GetHostEntry(hostname) instead of obsolete Dns.GetHostAddresses.

Here is an excellent example of how it is doing: http://www.codeproject.com/Articles/854/How-To-Get-IP-Address-Of-A-Machine

you could use the windows management classes to do this, it also works for remote machines that are in the same domain (but I don't know if they need to enable or disable any security or policy settings for this to work). for example:
public List<NetworkAdapter> GetAdapterList()
{
ManagementClass mgmt = new ManagementClass("Win32_NetworkAdapterConfiguration ");
ManagementObjectCollection moc = mgmt.GetInstances();
List<NetworkAdapter> adapters = new List<NetworkAdapter>();
// Search for adapters with IP addresses
foreach(ManagementObject mob in moc)
{
string[] addresses = (string[])mob.Properties["IPAddress"].Value;
if (null == addresses)
{
continue;
}
NetworkAdapter na = new NetworkAdapter();
na.Description = (string) mob.Properties["Description"].Value;
na.MacAddress = (string) mob.Properties["MACAddress"].Value;
na.IPAddresses = addresses;
adapters.Add(na);
}
return adapters;
}
and to access a remote machine create the management class like this instead:
ManagementClass mgmt = new ManagementClass
(\\\\servername\\root\\cimv2:Win32_NetworkAdapterConfiguration);
this approach may get you more IPs than just the ones that have been registered in the DNS.

How do you determine which adapter is used?

I have a need to figure out which adapter is used when a connection is created. In other words, if I have multiple NIC cards (i.e. wireless, lan, etc) on my machine, which card is being used for the connection?
If anyone can point me in the right direction...

In C#
foreach(var nic in NetworkInterface.GetAllNetworkInterfaces.Where(n => n.OperationalStatus == OperationStatus.UP)
{
if(nic.GetIsNetworkAvailable())
{
//nic is attached to some form of network
}
}
VB .NET
ForEach nic in NetworkInterface.GetAllNetworkInterfaces.Where(Function(n) n.OperationalStatus = OperationStatus.UP)
If nic.GetIsNetworkAvailable() Then
//nic is attached to some form of network
End If
Next
This will only test active working Network Interfaces that are connected to an active network.

Why don't you use the MAC address?

Maybe you could map it by the MAC Address:
var nics = NetworkInterface.GetAllNetworkInterfaces();
foreach (var nic in nics)
{
if (nic.OperationalStatus == OperationalStatus.Up)
{
var mac = nic.GetPhysicalAddress().ToString();
if (mac == "your:connections:mac:address")
{
/* ... */
}
}
}
The "your:connections:mac:address" part you can figure out following this method, using the IP address of the LocalEndPoint.
How do I obtain the physical (MAC) address of an IP address using C#?
It's not beautiful, but it could work.