R190W Firmware v4.4.x 100meg MTU issue / bug.


Just a quick heads up. There is a bug in R190W (I'd imagine the V as well) firmware versions v4.x.x which appears to be affecting the MTU on WAN port when connected to a Force 200 which has a gig port. The R201 routers don't have this issue as far as I've seen (becuause they have a gig wan port)  – I know this because I had this same issue with at another site, and swapping to a R201p resolved the flaky PPPoE connections. Having the exact same issue with a brand new R190W, was just a little too coincidental. Symptoms:

  1. PPPoE to a Mikrotik PPPoE server drops exactly every 30 seconds.
  2. If the MTU on the LAN of the Force 200 is 1500 or more, accessing the Web UI of the cnPilot over the WAN port chugs and odly enough, will respond for about 3-5 seconds every 30 seconds.

Steps tried to resolve the issue on v4.x.x firmware:

  1. Check the Force 200 signal strength and throughput.
  2. Set Force 200 to 100meg full and half.
  3. Set MTU's lower and higher on the Force 200.
  4. Set Max MTU and Max MRU on PPPoE server.

Solution (if you have to do this remotely):

  1. Access the Web UI of the cnPilot slowly but surely within the 3-5 seconds that the interface becomes responsive until you can get to the Administration section.
  2. Download the config or (pull from cnMaestro if you can) and edit the line that says "DBID_PPPOE_MTU=1500" and set it to something lower such as "DBID_PPPOE_MTU=1492".
  3. Upload the config and reboot. Now the interface should be quick.
  4. Upload firmware (downgrade) to 4.3.4-R8 via cnMaestro or WebUI and you should have stable connections.

This issue could have been introduced by upgrading directly to 4.4.2, but I will have to analyze the config from a 4.3.4 router (not upgraded yet) and compare to the config created by 4.4.2. As far as I've seen Force 190's with 100meg ports don't have this issue.

Anyone else experience this? If someone from Cambium wishes, I'll create a ticket for this.

Cheers, Tim.

I can see that the stock firmware is 4.3.5-R1 which is higher than I have. Any idea where I can get this? It's not in Archive under support download.

Cheers, TIm.