Ubuntu: List all connections to a single nic command?

Frank Jeagar · 29 Nov 2017 at 10:02

I've installed Ubuntu on my work PC to get around a lot of the restrictions placed on the Windows 7 install they give us, and one of the things I've done is set up a WiFi hotspot for us to use.

I'd like to monitor connections and/or traffic on the hotspot, but if I try to list all of the connections to my PC then I get like 100 IPs because it is also showing me all of the connections from our wired work network.

Since the work network is connected via an onboard ethernet port and the hotspot is via a wireless expansion card, I wondered if there was a way to show all of the connections to a specific nic? That way I would be able to see the connections to the hotspot and not the work network.

Thanks in advance for any help!

SMN · 29 Nov 2017 at 11:08

netstat is your friend: https://docs.oracle.com/cd/E23823_01/html/816-4554/ipconfig-142.html

I use 'netstat -tulpn' generally, and you can find in that doc above how to specify a particular interface only.

Frank Jeagar · 29 Nov 2017 at 12:40

SMN said:
netstat is your friend: https://docs.oracle.com/cd/E23823_01/html/816-4554/ipconfig-142.html

I use 'netstat -tulpn' generally, and you can find in that doc above how to specify a particular interface only.

That has helped, thanks a lot!

Frank Jeagar · 29 Nov 2017 at 12:43

If anyone else comes across this, I've found arp-scan was also good (not installed by default "sudo apt-get install arp-scan").

You can use "sudo arp-scan -l --interface=wlan0" where wlan0 is the name of the connection you want to look at (which you can check with "ifconfig").

This will give you a list of IPs connected to the network connection of your choice.