RB850Gx2 and ROS 6.20

Hardware MikroTik hardware general
1

I was having an issue with TCP drops on this platform when running ROS 6.20 and VLANs.

My Setup.

  1. Basic Routing, no NAT.

  2. Using it as a router to some Cambium ePMP1000 radios.

  3. Basic Bridge joining a vlan tagged 3 on the ports connected to the ePMP1000 radios.

  4. IP address (ePMP gateway) assigned to bridge.

  5. I would loose web access to ePMP radios. I tested by telnetting to port 80 and would only get part of the embedded web server response.

  6. When using SSH to the devices, I would be able to only receive so many characters until the session would hang.

  7. When I moved the radios off the VLAN an moved the bridge to the interfaces rather than the VLANs, everything would operate correctly.

  8. I tried multiple releases of software on the Cambium ePMP radios with the same result.

  9. Upgrading ROS to 6.21.1, resolve the issue.

Has anyone else seen anything similar? Could it have been the L2 MTU that people have been complaining about on the forums? The ePMP is currently set with a MTU of 1500. Because 6.21.1 solved the issue, I figure it is something to do with ROS 6.20 and the hardware platform. I worked with Cambium and their testers and they were not able to reproduce my issue when utilizing hardware from different manufactures.