Created attachment 163975 [details] Network applet with one WiFi and two Ethernet connections. SUMMARY I have an integrated Ethernet card, which is connected to a local LAN with Internet connectivity using DHCP. I also have another, USB-connected device which presents itself as an Ethernet device and provides DHCP as well. When I am connected to my local wired Ethernet, I'm unable to be connected with the other Ethernet device, because when I click 'Connect' in the Network applet for one connection, the other connection always automatically disconnects. See the attached picture - when I click connect on one situation, the result is always the other situation. Note that I changed the name of the connections, but that shouldn't affect the issue here. (I expect this applies to any two/multiple same-type connections, but I have no way of testing this.) STEPS TO REPRODUCE 1. Have a computer with two Ethernet cards 2. Have one Ethernet card connected to LAN (with Internet access) 3. Connect the second Ethernet card to anoether, separate, non-overlapping LAN (without Internet access) 4. Click Connect for the second Ethernet device in the Network applet OBSERVED RESULT Both Ethernet devices are connected andNetwork applet shows both devices as connected. EXPECTED RESULT The first connection gets disconnected, leaving only the second device is connected (or one-at-a-time, if you will). SOFTWARE/OS VERSIONS Linux: Manjaro Plasma (up-to-date as of 2023-12-07) KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.112.0 Qt Version: 5.15.11 ADDITIONAL INFORMATION The same setup resulted in two connected networks back when I used Manjaro Gnome. The current setup with Manjaro Plasma is a fresh install to eliminate any issues from trying to just switch the desktop. I assume there is a way to make this happen in System Settings - Connections, but it is not obvious to me how it can be done. Possibly something related to "Restrict to device" setting? Note that the two networks use non-overlapping private IP address spaces, DHCP, and only one has Internet connectivity - routing is therefore a non-issue.
It turns out all I had to do was the following: Go to System Settings - Connections - (the integrated Ethernet device) - Wired - Restrict to device, and from there select the MAC address of the said device. Now when I plug in the other USB device that acts as a Ethernet device, its interface now gets an IP address from the device's DHCP server. FWIW, I flashed Manjaro Gnome, and it allows multiple wired DHCP connections OOTB, as does Windows (the last time I used Windows 10 in such environment a few years back). So, technically the bug is solved, but to me this still completely counter-intuitive, as only one active connection isn't something that I expect from a desktop system (although my technical background gives me a bias on this). This might be a usability/documentation issue instead -- I'll let others be the judge of that and flip the bug status accordingly.
Bulk transfer as requested in T17796