PM8000 MAC Authentication Bypass Functionality

[Nicholas_Brown]

I have a customer that is attempting to connect a PM8000 (FW 4.5) to their network using IPv6 DHCP.  The meter is configured to do such.  The issue is that they are showing that the meter does NOT seem to be broadcasting it's MAC address via ARP.  They can see something connected to the port, but no MAC address.  They test this during a power cycle and when unplugging and re-plugging the Ethernet cable.

There are other PM8000s on different network segments (FW 3.1) that seem to be operating correctly and it is assumed they were able to broadcast their MAC address.  I don't have any other details on these.

Is there any potential that the FW versions may alter this behavior, or has anyone run into this issue of a PM8000 not broadcasting its MAC address for IPv6 DHCP?

Thank you.

[Charles_Murison · Accepted solution]

Hello @Nicholas_Brown 

Firmware does not change the meter's ARP behavior. A meter with V4.5.0 that I tested with direct  connection had ARP message that included the meter's IPV4 address. With DHCP enabled, you see see a message from the meter requesting IPV6 IP address, subnet and gateway information after a power up. 

The devil in the details could be that the meter does not send out additional ARP messages after meter is powered on. There are ways to make the meter send out messages with the meter's MAC address. One way to do this is to have the meter modbus master a non existent IP address outside the subnet range. When meter tried to connect, will send a message out that includes the meter's MAC address. This works for IPv6 address, not sure if this would also work with IPV6.

Regards,

Charles