I need to assign a unique IP address (local) for a device we will be connecting into our system via. USB. The actually assigning I will do over RS232 (don't ask!) by telling the device what it's IP is.
I would like to somehow find a usable address relative to the local PC in order to tell the device which to use. Is there a way of enumerating or finding a usable address in C#? I don't want to simply use a fixed one in case of possible clashes with other devices.
I've done a search here and there's lots of people wanting to find the current IP, or the IP of an already existing device, but I can't find much about generating a usable, unique one.
Thanks for any assistance you can give me.
Assigning static IP addresses (even if you ping them) is a bad idea.
What happens if the IP address you've assigned is to a device that happens to be offline right now?
Use DHCP if you can, and consider prompting the user if you can not retrieve an IP address from DHCP as to what it should be assigned to.
I am not ware of a native C# library for DHCP client's, but using pinvoke will get you what you're after. Example code (not tested) here, http://www.ianatkinson.net/computing/dhcpcsharp.htm
From http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
The Dynamic Host Configuration Protocol (DHCP) is a network
configuration protocol for hosts on Internet Protocol (IP) networks.
Computers that are connected to IP networks must be configured before
they can communicate with other hosts. The most essential information
needed is an IP address, and a default route and routing prefix. DHCP
eliminates the manual task by a network administrator. It also
provides a central database of devices that are connected to the
network and eliminates duplicate resource assignments. In addition to
IP addresses, DHCP also provides other configuration information,
particularly the IP addresses of local Domain Name Server (DNS),
network boot servers, or other service hosts. DHCP is used for IPv4 as
well as IPv6. While both versions serve much the same purpose, the
details of the protocol for IPv4 and IPv6 are sufficiently different
that they may be considered separate protocols.[1] Hosts that do not
use DHCP for address configuration may still use it to obtain other
configuration information. Alternatively, IPv6 hosts may use stateless
address autoconfiguration. IPv4 hosts may use link-local addressing to
achieve limited local connectivity.
Ok, not really sophisticated or anything, but why don't you just try to ping the ips, starting by the lowest, and pick the first one which doesn't respond?
Related
I want to connect two computers with an Ethernet cable without the user having to set up a LAN through the Control Panel and then transfer data between two instances of my app - one running on each computer.
As soon as I have a connection with an IP address for each computer, I know I can easily transfer a file by using Sockets, Pipes(?), WCF... But both computers are also connected via wifi to a router, so how can I somehow tell the computer that for a specific IP address - please use the cable? (I might be getting all of this wrong. Please feel free to correct me.)
I can use a UWP app or a .net (Winform/WPF) app. Either technology is fine. But this must be done in code, not by the users setting up a LAN through the Control Panel. Also, IPv6 is fine too.
Each network card has its own IP address, so both of the computers will have IP address for the WIFI network and another IP address for the ad-hoc link.
The addresses for the ad-hoc link can be set to an address in one IP segment, for example, 10.0.0.1 and 10.0.0.2, if the WIFI addresses are in the range of 192.168.X.X.
Your OS will know which card is related to each IP segment.
Start with System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces().
Filter out the Type=EtherNet interfaces and make sure they're Up. You may also have to watch out for virtual adapters etc.
From the selected adapter you can get Address Information etc. The IPV4 address should probably be enough to get you started.
We're developing some hardware devices in our company that need to communicate through TCP on the network with our application. The devices have some restrictions, such as they do not have a display or a dotmatrix to show any current configuration, such as IP or mac address. Therefore, it is not possible to configure the IP configuration directly on the device.
When they are connected to the network for the first time, there is a high chance, that their current network configuration does not match with the network being connected to.
E.g.
They are configured to use DHCP and the network does not provide any DHCP.
They are configured to use a manual IP, such as 192.168.1.1 with a subnet mask of 255.255.0.0, but the network is set up to use 10.X.X.X as IP range with a network mask of 255.0.0.0
We now want to develop a standalone application, that lists all devices being connected to the network and change the IP configuration to a specific one (matching the network needs).
What needs to be set up on the device (running Linux) in order to be capable of the things posted above?
What needs to be set up on the client side application in order to display the devices and reconfigure them if mismatching? The Application should be a .NET WPF / C# application if possible, admin rights can be aquired if needed.
Are there any restrictions / scenarios under which we are not able to detect those devices or set up the new network settings?
Leaving out any security issues I would use a udp broadcast to 255.255.255.255 which will been received by any devices. When you put all valid subnets into the payload the client will know that it is wrongly configured and has to answer back as broadcast (since it might be in a different subnet and a unicast is impossible without any valid routing tables)
But please keep in mind that this can open security issues since you will publish on scans all valid subnets which might been very interesting for attackers.
If you know e.g. the Mac addresses of all possible device you may could encrypt the UDP payload which can only been encrypted with the right Mac addresses.
This is what DHCP, BOOTP, RARP are for. Using DHCP and friends to do this sort of thing means a device plonked on a network stands the best possible chance of getting a valid config in the first place.
If you MUST have your own app doing the management of the issue of IP config, then perhaps consider using the DHCP protocol in your management/server app.
If your devices must not speak to a random DHCP server then consider having them either ignore responses that don't have certain attributes in the reply (bit inefficient since it may keep asking and may tie up IPs) or use DHCP on different ports... At least you're not reinventing the wheel then.
Using existing protocols has the benefit that network analysers can understand what's going on too, system admins can debug and make intuitive guesses as to problems, etc.
Possible Duplicate:
Get all IP-Hosts in Lan from mobile device
How can I get programmaticaly all the hosts in a wireless network?
I know the wlan I'm working in and I am connected to it. Now I want to show a list of the hosts (or at least their IP-Addresses).
How can I accomplish this, and are there special points if I work on windows mobile with compact framework and want to do that?
There are lots of ways. For example:
ARP:
http://msdn.microsoft.com/en-us/library/aa366358%28VS.85%29.aspx
WMI:
http://weblogs.sqlteam.com/mladenp/archive/2010/11/04/find-only-physical-network-adapters-with-wmi-win32_networkadapter-class.aspx
ICMP:
http://social.msdn.microsoft.com/Forums/en/netfxnetcom/thread/8a528983-915b-4d94-836e-804b03e6261f
Etc
The only way to get all the hosts in a network is to use network scanning.
You could ping all the valid IPs of the network the device is in.
Or you could check every valid IP of the network on the local DNS service for a name and list the different names you found with corresponding IP.
An IP would be valid if the Bits corresponding to the subnet mask are the same to the IP the device has.
The easy answer is: You can't. Going more in detail: you can't unless you have a protocol to discover your hosts, for example, NetBIOS. You can call NetBEUI (NetBios User Interface) through pInvoke. Look at this previous post:
Netbios support in .NET?
Another approach you can use is to ping all the IP addresses in your WLAN range and wait for responses. This is not a good approach as it is very resource consuming.
Is there an easy way to get a MAC address of a machine connected to my app via a TCP/IPv4 socket?
Or in more general terms:
If I have the IP address, what is the best way to get the corresponding MAC address in IPv4?
MAC addresses are used only for the next hop. This basically means the client's original MAC address won't be visible after it's first hop. In the general sense, if you are not on the same physical segment as the client, you have NO way of taking an IP and getting the MAC (or vice/versa).
You can't, without having something (or the client itself) on that other network.
MAC addresses are used on the second layer, the data-link layer, of the OSI model for networking. MACs are specific to Ethernet. When you get to the Internet, IP addresses are used. Not everything connected to the Internet uses Ethernet at lower layers.
There are also other protocols other than IP that can be used.
Basically, your computer only knows what is on its physical network segment. If it has to go outside for anything else, it only knows the MAC of the gateway to get there.
It is the ARP table's job to keep that information. The best thing to do would be to read it out of there.
You might consider reading the answers to Query ARP cache to get MAC ID. The questioner was using Java, but otherwise its your identical question.
Is it true that, if I want to make an IP spoofing program, I need only a program that can change my machine IP address?
If true how can I use System.Net - IPAddress Class to set the ip address?
No, it is not true. Changing your machine's IP address is not IP spoofing. IP spoofing is when you create network packets that have a source IP address that does not match the actual IP address of the source machine.
http://en.wikipedia.org/wiki/IP_address_spoofing
This could be achieved using RAW sockets or WinPCap using SharpPCap to interop to WinPCap
http://www.tamirgal.com/blog/page/SharpPcap.aspx
Your machine IP address is simply the IP address given to your machine to be used internally by devices within your home network. This is how routers, switches and other client devices can deliver and exchange packets.
You cannot spoof your external-facing IP in this manner. Using proxies will make the proxy's IP appear to be your external-facing IP.
I do not suggest changing your internal IP unless you know what you are doing and actually have a need for it to be static. For example, I forward ports on my router so I can run services. The router knows to point that traffic directly to my internal IP. Because DHCP can change your IP (due to lease expiration and what not), it's best that I make my internal IP static.
Also, depending on your network configuration, your internal IP has a certain format, like 192.168.1.X.
The best way to http://www.change-ip-proxy.com>change your ip address is through a proxy. In my search for a proxy, I found that having a reliable company behind the proxy is very important. Everything you do is sent through the company’s proxy, so you want to be sure that you can trust them to not read or steal your personal information. Or else there's no point in having a proxy.