PMP450 SM Eth0 device not in bridge table

We are having a very strange issue with a number of SMs.

We use PPPoE from client routers across bridged SMs. The issue presented as PPPoE sessions failing to establish. I have traced this to pppoe-discovery packets not being received from affected client routers.

There are only two entries in the bridge table of affected SMs (NI1-Eth0Mgmt and NI2-Priv-RF-Mgmt)

Occassionally Eth0 pops up with a Physical address of 000000000001, then drops off again.

Initially this was on two clients on one base station, it is now affecting approx 14 clients on 3 base stations, all on the same site.

Base stations are running 15.1.3, SMs are mostly running 15.1.3 also, I have tried upgrading some to 15.1.5 and 15.2 but the issue persists. Everything has been rebooted at various points.

Has anyone seen this issue before / does anyone know how to resolve?

We have traced this issue to TP-Link routers.

All affected clients have TP-Link routers, when we replace the TP-Link with another router the issue is resolved. The affected routers appear to work correctly in DHCP mode but not PPPoE. We have seen that if the routers are factory reset, the MAC changes to BABEFACE0841. Even a firmware flash doesn't seem to resolve the issue so it is possible the corruption is pretty low level...

It doesn't look like a Cambium SM issue so if I can figure out how to close the thread I will ;-)

1 Like

I would be interested in seeing a wireshark capture of the PPPoE attempt if you could find a way to do that with a hub between the TP-Link and the SM.  Otherwise, let us know the model as well.  I dont think we have an issue here, but always interested in taking a look just in case.