find mac address of all connected systems

Question

How can I find out how many system are connected to the local network and how can I get all IP and mac address of these systems.
Is their any command/package to show the IP details?
Can I use this command/package in our Firewall(IP Corp onLinux OS) to block unauthorized systems?

After I posted an answer, I noticed your comment. It does seem to be a duplicate of that question. — hazrpg, Jul 22 '14 at 12:36
If you have access to the router the information will you are locking for is shown there. — Thomas K, Jul 22 '14 at 12:44
See the link to the duplicate, esp. the answer about nmap. — Jos, Jul 22 '14 at 13:47

score 1 · Answer 1 · answered Jul 22 '14 at 12:24

I don't know a way to actively scan a network for live systems, although I'm sure such tools exist.

However if you just want to know what systems are connected and which MAC address they have I would just have a look at the list of active clients on your router/DHCP server.

You can then enable MAC filtering on your firewall and white list the MAC addresses that you want.

score 1 · Answer 2 · answered Jul 22 '14 at 12:32

There's a command called arp-scan that might do the trick for you, you will need to install it first:

sudo apt-get install arp-scan

Here's a link to the man pages that will outline how to use it: http://manpages.ubuntu.com/manpages/trusty/man1/arp-scan.1.html

As an example though, you could do this:

sudo arp-scan --interface=eth0 --localnet

Where eth0 is your local ethernet device. You can find out what yours is called via ifconfig

WiFi would be something like wlan0. – hazrpg Jul 22 '14 at 12:33 — hazrpg, Jul 22 '14 at 12:33

find mac address of all connected systems

2 Answers2