I am working on DHCP Billing System project. Only devices which administrators include their mac addresses can get ip address from DHCP. There are some mac addresses which belong to devices of former workers. I need monitor DHCP traffic and determine which mac addresses dont make request to get ip anymore. How can i do it?
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I have a device in my local network with unknown IP address and outside of my sub-net (it was configured previously as static IP in another network). I know though its MAC address. Is it possible with java to communicate with that device using only its MAC address?
I want to get the web user/client mac address, i.e i want to restrict the users to open my web application with register mac address only. So other systems could not open my web application,
For example, if the user entered URL in the browser and enters, the request will go to the server, in the server side is it possible to capture the mac address of the client?,if it is possible i can restrict him to open my application by checking with my already registered mac addresses.
please help me.
The MAC address does not survive beyond IP routers. You can't find the client MAC address from a remote server.
In a local subnet, the MAC addresses are mapped to IP addresses through the ARP system. You can find the MAC address of computers within your subnet using 'arp -a' or 'nbtstat -A ipaddress' command in windows.
However, when your packets passes though the router from the local subnet through the gateway out to the Internet, the originating MAC address is lost.
I'm trying to connect my pc to my android phone via WIFI..
But the problem is anytime I disconnect my phone from WIFI and turn it on again
I'm getting a different IP address so my pc doesn't connect until I change the IP address to connect to.. Is there any way to get the correct IP address of the phone?
That might be a router settings issue. Have you ever heard of "DHCP Reservation"? Most routers support such an option, which enables the router to memorize an IP to every distinct client ever connected and then to assign this ip to the respective client every time it reconnects.
Check your router settings / documentation for this option.
Here is a link, which could help you with your further investigation:
http://lifehacker.com/5822605/how-to-set-up-dhcp-reservations-so-you-never-have-to-check-an-ip-address-again
We are launching an ERP application on cloud and hence planning to capture the system ip address of the clients machine who access the application from our server.
This ip address that we are fetching is it the system ip or localhost ip?
It is fetched using
InetAddress local_ip=InetAddress.getLocalHost();
InetAddress remote_ip=InetAddress.getByName(request.getRemoteAddr());
Is it secure to fetch the ip address or mac address? As i know the ip address is unique only across a network.
Thank You
You will not be able to track the mac unless you are on the same network. Once the packet crosses a router the mac addr becomes the mac of the routers you bounce across at each hop. Mac addresses are available to the broadcast domain only. Some devices support proxy arp though.
IP addresses might change over sessions. Think about NATted clients and DHCP assigned addresses. These keep changing. Same IP might represent another client at another time.
Considering security, as mentioned in a comment, no.
I have two android devices - one is a server, second is a client. I run WiFi hotspot on server (using some external app, like QuickSettings), and then connect to this hotspot on second device. I have an application which transfers some data between these devices, so I need to get an IP address of the server to be able to create a socket on client. So my question is how can I do that inside my application (not justing by typing the proper IP manually)?
Did you try assuming the hotspot is the first IP in the valid range?
I mean: The hotspot gives you device an IP and a mask (and it should give even a gateway). The IP of the hotspot is the IP gateway, but if the hostspot did not tell your device such IP, the gateway is usually the first IP in the range allowed by the mask.