We're trying to obtain all ip addresses and hostnames of machines on local network, we have a display box(BrightSign box) which is connected to local network and we want to have all information about that box. We can find ip address of it, but cannot get host name. So we can't determine which ip adresses is assigned to that box. (We can learn the ip address of the box by using its own program; but we want to detect automatically)
here the code we use in c#
`
public void scan(string subnet)
{
Ping myping;
PingReply reply;
IPAddress addr;
IPHostEntry host;
for (int i = 1; i < 255; i++)
{
string subnetn = "." + i.ToString();
myping = new Ping();
//string data = "aa";
//byte[] buffer = Encoding.ASCII.GetBytes(data);
//PingOptions optionss = new PingOptions(64, true);
int timeout = 1000;
reply = myping.Send(subnet + subnetn);
if (reply.Status == IPStatus.Success)
{
try {
addr = IPAddress.Parse(subnet+subnetn);
host = Dns.GetHostEntry(addr);
txtHosts.AppendText(subnet + subnetn + host.HostName.ToString()+"\n");
}
catch {
}
}
}
}`
if we use this code, system can detect all ip but not host names belongs to telephone and the box i mentioned.
Briefly, we need to have all machine name and ip addresses on local network.
So, do you guys have any idea what's the problem and what can we do to solve this issue. We made some research and tried some ways. We tried to send ping the ip address which we cannot take the hostname and we realized that if ttl of machine is set to 64, we cannot take the hostname, but if its ttl is 128, we can manage to learn the hostname, i also adjusted ping settings to test this challenge, but i still have problem.
I am looking forward to hearing your response.
Thank you all.
Machine name could be DNS or NETBIOS or something else. I recommend you check out NMAP and see what it can do. If you want to emulate that, you can ask about a specific requirement. For example, getting a DNS name means querying the DNS server, a computer wont reply with a name just from an ICMP ping. If the computer security settings allow it, you can do a netbios query, or use WMI, or if you are in a domain, query the domain server.
I don't know what brightsign is, but there is no law that says a device must have a DNS name, some appliances just use IP address and thats it. Also there's no law that says a device must respond to ping or any other protocol.
Related
Assume there are two systems; System1 and System2.
System1 - Windows XP
System2 - Linux.
I have installed a WPF application on System1. A user on System2 connects to System1 via a Remote Desktop Connection and launches the WPF application.
In the WPF application, I can get the local IP address and Windows Login Name for System1 using the following code.
private String GetIP()
{
string strHostName = "";
strHostName = System.Net.Dns.GetHostName();
IPHostEntry ipEntry = System.Net.Dns.GetHostEntry(strHostName);
IPAddress[] addr = ipEntry.AddressList;
return addr[0].ToString();
}
String WinUserName_withNetwork = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
String WinUserNameOnly = System.Environment.UserName;
My problem is I want the IP address and user name of the user logging in from System2.
What do I need to do in order to get that IP address and user name?
As far as I understand the question you want to know the IP address of the System2 from the System1 computer and the name of the user logged thru the remote connection. Am I right?
Assuming that you can use environment variables to gather this information:
CLIENTNAME: contains the name of the computer connected thru remote desktop.
USERNAME: contains the name of the user logged in.
Hope this helps.
Refer following Code:
IPHostEntry iPAddress = DNS.GetHostByName (HostName);
IPAddress [] IPAdd = iPAddress.AddressList;
for (int j = 0; j < IPAdd.Length; j++)
{
Console.WriteLine ("IP Address {0}: {1} ", j, IPAdd[j].ToString ());
}
Can also refer THIS doccument.
Simply open a command prompt / shell and type IPCONFIG
Look for an IP4 address. Quite often you'll see it's "127.0.0.1". Type NSLOOKUP to get the name of the computer.
Hope this helps
Using C# Winforms I am trying to automatically detect the local machines IP address through which it can connect to a particular remote DNS/IP address.
One senario is running over a VPN, with the remote address being 10.8.0.1 and local address being 10.8.0.6, netmask of 255.255.255.252
Iterating through the local addresses and checking if the remote and local are on the same subnet obviously fails and I am unsure of how else to do this.
Here is some sample code that should get you the information you're looking for. It creates a UDP socket and calls Connect() on it (effectively a NOOP), and then checks the local address.
static EndPoint GetLocalEndPointFor(IPAddress remote)
{
using (Socket s = new Socket(remote.AddressFamily,
SocketType.Dgram,
ProtocolType.IP))
{
// Just picked a random port, you could make this application
// specific if you want, but I don't think it really matters
s.Connect(new IPEndPoint(remote, 35353));
return s.LocalEndPoint;
}
}
static void Main(string[] args)
{
IPAddress remoteAddress = IPAddress.Parse("10.8.0.1");
IPEndPoint localEndPoint = GetLocalEndPointFor(remoteAddress) as IPEndPoint;
if (localEndPoint == null)
Console.WriteLine("Couldn't find local address");
else
Console.WriteLine(localEndPoint.Address);
Console.ReadKey();
}
Note that this is effectively an implementation of this answer, but in C#.
The routing table determines which local port to use. I don't know of a way from C# to get it other than to run the route print CLI command. If there is a network match it uses that port, otherwise it uses the default route.
http://www.csharp-examples.net/local-ip/
Give that a shot.
I'm programming in C# and i want to detect a cell phone(Name, IP address, RSSI, ...) in Wireless Network (Wi-Fi) to calculate after that the distance between my computer and the cell phone
Actually, I'm able to detect computers name connected to the same network with :
using System.DirectoryServices;
...
List<String> _ComputerNames = new List<String>();
String _ComputerSchema = "Computer";
DirectoryEntry _WinNTDirectoryEntries = new DirectoryEntry("WinNT:");
foreach (DirectoryEntry _AvailDomains in _WinNTDirectoryEntries.Children)
{
foreach (DirectoryEntry _PCNameEntry in _AvailDomains.Children)
{
if (_PCNameEntry.SchemaClassName.ToLower().Contains(_ComputerSchema.ToLower()))
{
_ComputerNames.Add(_PCNameEntry.Name);
}
}
}
But I cannot find my cell phone that is connect to the same wi-fi network.
How can I resolve this problem ?
Thanks!
I dont think ActiveDirectory is going to work too well for you here, your likely going to need to work more closely with the access point itself to fetch the RSSI values. Unless there is a particular domain knowledge you have about all phones being part of an ActiveDirectory its like Jean said: you only get MAC address, possibly IP address and the RSSI value.
If you are only interested in distance you will likely need to test out a range of distances with a particular device and use the RSSI-distance list you to guestimate the distance of a new device based on the RSSI value for it.
A problem you will encounter is you might have X RSSI Value for one device, and 2X RSSI Value for another device and they could very well be the exact same distance. Although if you are only interested in phones I would expect the fluctuation to be less severe.
A more accurate way to do this would be to have multiple Access Points setup and triangulate the device's position with a bit of math, the plus side of this is also giving you distance as well as direction, amounting to location
Unless I am mistaken, only the Wi-Fi access point itself will have access to the full list of devices. Even then, it doesn't know what type each device is. It knows the MAC address of each device, and it may know the IP it was allocated (assuming it is also a DHCP server), but beyond that the device could be anything from a laptop to a television.
If you are a network administrator, then I can see how this might be useful - if you have a policy where only certain devices are intended to connect to the network, then it makes sense to hunt down "rogue" devices. Otherwise, I can't see any good reason to try and help you any further.
If you know what ip address the phone has then you can try and ping the device.
bool isIpReachable(string ipAddress)
{
Ping pingSender = new Ping();
PingOptions options = new PingOptions();
options.DontFragment = true;
string data = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
byte[] buffer = Encoding.ASCII.GetBytes(data);
int timeout = 120;
try
{
PingReply reply = pingSender.Send(ipAddress, timeout, buffer, options);
return reply.Status == IPStatus.Success;
}
catch (Exception ex)
{
Console.WriteLine("Error: " + ex.Message);
}
return false;
}
I have a situation where I ping a range of IPs in the network. Then, I try to connect to the successful pings.
My aim is to connect to specific equipment that has a specific MAC prefix. For example, when I ping a range of 100 IPs, I might get 20 replies. These replies include computers, printers, and possibly the hardware I am trying to connect.
Currently what happens is that when I try to connect to anything other than the hardware I would like (i.e computer, printer) I get a timeout connection.
This is fine, however, it is not efficient. I would like to filter out the successful ping list by using the MAC address, however, I have not yet been able to find a solution that allows me to seek a MAC address prior to connecting the hardware.
I have looked through most the MAC questions on here, but none fit my needs.
Any ideas??
I was able to find the solution here: http://pinvoke.net/default.aspx/iphlpapi/SendARP.html
The following method returns the MAC
internal static string GetMAC(string ip)
{
IPAddress dst = IPAddress.Parse(ip); // the destination IP address Note:Can Someone give the code to get the IP address of the server
byte[] macAddr = new byte[6];
uint macAddrLen = (uint)macAddr.Length;
if (SendARP((int)dst.Address, 0, macAddr, ref macAddrLen) != 0)
throw new InvalidOperationException("SendARP failed.");
string[] str = new string[(int)macAddrLen];
for (int i = 0; i < macAddrLen; i++)
str[i] = macAddr[i].ToString("x2");
return string.Join(":", str);
//Console.WriteLine(string.Join(":", str));
}
Hey all. I have written a program that sequentially scans certain parts of a LAN for computers (code will be provided). However, when I run this code, it only returns the DNS HostName of the computer it is running on. I looked into using WMI, but I cannot, as I will not always have priveleges to the computers being found. Is there any other way to find a local computers HostName?
using System;
using System.Net;
using System.Net.NetworkInformation;
using System.Text;
namespace CheckLocalNetwork
{
class PingCheck
{
public static string fullip;
public void CheckSequentialIP()
{
IPHostEntry IpEntry = Dns.GetHostEntry(fullip);
Ping pingSender = new Ping();
PingOptions options = new PingOptions();
options.DontFragment = true;
string data = "a";
byte[] buffer = Encoding.ASCII.GetBytes(data);
int timeout = 120;
PingReply reply = pingSender.Send(fullip, timeout, buffer, options);
if (reply.Status == IPStatus.Success)
{
Console.WriteLine("Address: {0}", reply.Address.ToString());
Console.WriteLine("Host Name: {0}", IpEntry.HostName);
Console.WriteLine("RoundTrip time: {0}", reply.RoundtripTime);
Console.WriteLine("Time to live: {0}", reply.Options.Ttl);
Console.WriteLine("Don't fragment: {0}", reply.Options.DontFragment);
Console.WriteLine("Buffer size: {0}", reply.Buffer.Length);
Console.WriteLine("");
}
}
static void Main(string[] args)
{
Console.WriteLine("Press enter to search for ip adresses that begin with 192.168.1");
Console.ReadLine();
for (int endofip = 1; endofip < 101; endofip++)
{
fullip = "192.168.1." + Convert.ToString(endofip);
PingCheck checkfullip = new PingCheck();
checkfullip.CheckSequentialIP();
}
Console.ReadLine();
}
All help is much appreciated.
Hmm - your code sample behaves as expected on my machine - i.e. it returns the hostname of the machine being scanned.
To investigate your problem deeper, have you tried using nslookup to check the ip addresses resolve?
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
C:\Users\Rob>nslookup <-- type this at a command prompt
Default Server: mydns.mydomain.co.uk <--- these two lines indicate the dns server being used to resolve your queries
Address: 192.168.0.1 <----|
> 192.168.0.5 <---- type in the ip address of one of the machines in question
Server: mydns.mydomain.co.uk
Address: 192.168.0.1
Name: myworkstation.mydomain.co.uk <---- this is the hostname, as reported by the DNS using a reverse lookup
Address: 192.168.0.5
If this doesn't return the machine name, then you may have a name resolution issue that is not related to your code.
If this all looks ok, then it might also be worth enumerating the IpEntry.Aliases collection. Are there any entries here, and do they make sense?
Finally - is the code you have above exactly the code that is going wrong for you, or is it a "distilled" example? The reason I ask is that the documentation for Dns.GetHostEntry states
"When an empty string is passed as the
host name, this method returns the
IPv4 addresses of the local host."
I also notice you're holding "fullip" in a static. If this is not the exact code that is causing the problem, especially if this runs multithreaded, is there a chance you are not initialising "fullip" before the Dns.GetHostEntry is called?
I may be way off, but I thought is was worth giving a brain dump of what occured to me as I looked at your problem :)
[EDIT:] - your comment to kdt has clarified something I misunderstood. I thought you were saying you always got back the hostname for your local machine, no matter which machine you "scanned" - which is very odd behaviour. In fact I think you are saying you just get back IP addresses for other machines (their IP address), and only get a hostname for your local. Disregard my last bit about the threading and the empty argument.
This is far more easily explained - your machine is almost certainly just not able to resolve the machine names - I expect my nslookup test I suggested will not return the machine names either.
In order to resolve these IP's to host names, your machine needs a DNS that has entries for these machines, or to have them in its local hosts file; your machine isn't actually asking the remote machine for its name when you do this call so it won;t be able to find it out without help from one of its usual name resolution paths.
It works for me, because my local DNS really does have entries for all the machines on my network, resolving their host names to ip addresses and vice-versa.