We've been provided with a new firmware for our telematics units, which connects to the Internet via a VPN provided by a mobile carrier; since this new firmware release, we've noticed that each and every device (based on Linux) has the same MAC address: DE:AD:BE:EF:00:00
I'm familiar with the workings of Ethernet and WiFi, but still somewhat new to mobile (GSM, LTE, 5G, ...) side of things.
Unless I'm completely mistaken, TCP/IP traffic is still routed to the actual endpoint via MAC addressing on the network layer, hence the need for unique MAC addresses.
Does this also apply to mobile (cellular) networks? If that's the case, that would imply that hundreds of devices (regardless of their IP addresses) with the same MAC address would cause major issues in the field when it comes to connectivity. Or is this a normal practice in the mobile/cellular world?
To date we haven't seen any issues, but we've only been experimenting with this new firmware for a few days and only today have I been able to establish a mobile network connection.
For reference, here's the output of
wwan0 Link encap:Ethernet HWaddr DE:AD:BE:EF:00:00
inet addr:<snip> Bcast:<snip> Mask:255.255.255.248
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:77 errors:0 dropped:0 overruns:0 frame:0
TX packets:1482 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:3088 (3.0 KiB) TX bytes:134897 (131.7 KiB)