How to get a list of all devices currently connected to the router in the terminal?

[_BLACK_BuLLeT_]

I have an ASUS TUF-AX5400 router with the latest Merlin (gnutone) firmware. How can I get a list of all devices currently connected to the router in the terminal when connecting to the router via SSH? The ping method is not convenient for me and takes a long time. Moreover, the router already knows all the devices connected to it, but how can I get them in the terminal?

 

[kuki68ster]

I have an ASUS TUF-AX5400 router with the latest Merlin (gnutone) firmware. How can I get a list of all devices currently connected to the router in the terminal when connecting to the router via SSH? The ping method is not convenient for me and takes a long time. Moreover, the router already knows all the devices connected to it, but how can I get them in the terminal?

 

[eibgrad]

What constitutes being "connected"?

Years ago in the days of analog telephones, being connected was clearly understood; you literally had a completed electrical circuit between the endpoints. But on a packet switched network, the terms "connected" and "active" are dubious.

Consider ARP. All arp tells you is if traffic from/to a device has been seen "lately", which might be as little as 10 minutes ago. Once clients go "quiet", the arp entries will disappear until activity resumes. Yet, the client may still be "connected", as in their laptop is connected over ethernet or wireless, they have an active DHCP lease and IP assignment, etc.

Given the above, and depending on what YOU mean by connected, it might make more sense to actually ping around the network, just in case some devices have gone silent, if only temporarily.

That's why when routers attempt to create any sort of connected/active list of devices, you have to take it w/ a heavy grain of salt. By design, packet switched networks strive to be stateless, which is what makes them so powerful and flexible. But it also makes it that much more difficult to define what exactly is a connected/active device. And not everyone will agree w/ the definition.

 

[JGrana]

As @eibgrad said so well, any scanning for devices is an approximation. I have tried all sorts of methods...

If you are running Entware, you could install nmap. This has given me the closest "approximation" ;-)

The typical command to ping all addresses on a network and report them is:

nmap -sn 192.168.1.0/24

The above assumes your network is 192.168.1.X with a 255.255.255.0 netmask. The command often takes quite some time and I usually run it a few times.
I just did a few runs now. The first one reported 74 clients, the next run reported 81.

 

[Viktor Jaep]

Latest RTRMON beta also shows these recent ARP clients, but sorted into their individual LAN/WiFi/Guest WiFi/VLAN buckets:

RTRMON - RTRMON v2.0.17 -June 8, 2024- Monitor your Router's Health (New: AMTM, Network Conn/Bandwidth/Diag + Port Scanner + Speedtest) (New BETA13 Available!)

Huge props to @ExtremeFiretop and @visortgw for their massive assist in troubleshooting the display of network clients in complex multi-guest/multi-VLAN configurations on the badass GT-BE98 Pro! You both rock! New Beta 13 is out to play with below! What's new? v2.1.0b13 - (TBA) - PATCH...

www.snbforums.com