Connecting device by Ethernet Disables Wifi on Mac

Question

Created Aug ’22

Replies 3

Boosts 0

Participants 2

Our company builds a printer from a Jetson Nano. The printer needs to connect to the internet using a wifi dongle-- but for the initial connection the customer connects to the printer using an ethernet cable in order to set up the wifi connection.

The problem is that when the customer connects via ethernet it disables wifi on the host mac PC. I know that there are settings the customer can change to prevent this behaviour, but we don't want our customers to have to change their device settings.

Is there anything we can do on the Jetson Nano, to prevent it from broadcasting itself as a DHCP server? So that a mac will never attempt to connect to the internet via an ethernet connection to the Jetson Nano.

Thanks, Peter

Boost

Answer 1

endecotp OP

Aug ’22

Is there anything we can do on the Jetson Nano, to prevent it from broadcasting itself as a DHCP server?

Yes, certainly; don't run the DHCP server process!

But... how exactly does the Mac talk to the Jetson during this wired setup process? Do you rely on the Mac getting an address from the Jetson using DHCP for this process to work? If you do, then the question should be "how to stop the Mac from trying to route via the Jetson for global IP connectivity"... to which the answer is, there is probably some DHCP option you can set. Or, do you use only link-local addresses and e.g. mDNS during this process?

0

Answer 2

petersdavis OP

Aug ’22

Thanks for your quick reply endecotp,

The problem is that we want our device to advertise its hostname to the network so that the customer can easily navigate to their device in a browser. This works when our device is running dnsmasq-base--removing dnsmasq solves the connectivity issue, but then the user can no longer connect to the device.

I read the archwiki on dnsmasq. and it has the following subsection:

Proxy DHCP In case there is already a DHCP server running on the network and you want to interoperate with it, dnsmasq can be set to behave as a "proxy DHCP", therefore only serving the #PXE server specific information to the client. This mode is only available with IPv4. Use the following syntax, providing the existing DHCP server address: dhcp-range=192.168.0.1,proxy

But I tried it and it did not resolve the problem. I appreciate the keywords! I'll do some googling to see if link-local or mDNS can solve my problem.

0

Answer 3

endecotp OP

Aug ’22

I don't think you want "proxy DHCP".

If you don't run dnsmasq, I expect that you see a link-local (169.*) address in the Mac's system settings, right?

Now run a mDNS advertiser i.e. Avahi on the Jetson. You may then be able to connect to jetson.local from the Mac. Or maybe not! I'm by no means an expert on this stuff.

0