TypeError: device must be a string about cap HOT 6 CLOSED

Did you check console.dir(device)? If it's not a non-empty string, you might try doing console.dir(Cap.deviceList()) to check what network interfaces and addresses are available.

from cap.

console.dir(device) is undefined, so that's a problem

console.dir(Cap.deviceList()) gives a few interfaces

from cap.

Ok, but none of the interfaces shown include the interface with the IP address you're trying? If that is true, then you may need to find out what is unique about the missing interface.

If you execute node -e "console.dir(require('os').networkInterfaces())", do you see the IP address?

Lastly, what OS and OS version are you trying this on?

from cap.

Is that supposed to be my own address?

What if I'm trying to monitor arp packets from everywhere?

(It does work if I change the device = Cap.findDevice('192.168.1.131'), to my ip, but that does something else).

I see my own address with node -e "console.dir(require('os').networkInterfaces())" and loopback.

Win10

from cap.

Yup, figured it out.

I just used this library (which builds off of cap) - so if anyone reads this in the future is trying to work with dash buttons - read this:

I needed to put my own IP, which wasn't very idiot friendly, but it doesn't need to be.

var nodeis = require('win-node-dash-button');
var svr = new nodeis.Server(),
    tide   = new nodeis.DashButton("MAC ADDRESS OF BUTTON - WIRESHARK IT (Filter: ARP)", function () { console.log("Button pressed"); });

svr.register(tide)
   .start("YOUR LOCAL IP (like 192.168.1.111)");

from cap.

Not working for me, still I am getting undefined on line device = Cap.findDevice('192.168.1.131')

from cap.