RSTP - Root Port election

RouterOS General
1

I’ve been searching this forum and found some topics with similar problems, but none of the solutions presented seem to be resolving the problem.

Problem:

Packet loss present to multiple hosts on a layer2 segment for sporadic periods of times. It appears to be a root port election problem as the only hosts effected are the ones connecting in station-wds mode or beyond. No traffic will pass to those members of the RSTP bridge at random intervals.

                                  A
                                / | \
                               B  C  D
                             /    |    
                            E     F

A is supposed to be the root port. It has RSTP enabled and a priority of 1000. All other RSTP enabled devices have a priority of 8000. I changed the MAC address of Host A to be the lowest one on the segment its something like 00:00:00:10:10:ab. Even with these settings changed I can’t get the packet loss issues to go away. It’s like the other devices (B-F) are randomly changing the root port thus freezing network traffic.

Hosts B-D are connecting the the AP (host A) via station-wds modes, E and F are connecting to B and C respectively via CAT5 ethernet.

I’ve tried adjusting port costs and priorities on Host A for ports B-D with little to no effect. Any solutions are much appreciated..

Also I’m running 4.11 on most devices some may be 4.5 or newer.

2

Nevermind,

Looks like it was a loose connection on one of the ethernet ports, must have been feeding garbage into the network causing the packet loss. I have no other explanation, but it was fixed when the ethernet cables were unplugged/replugged into the switch.

Symptoms were very similar to a root port election problem as the packet loss was somewhat consistent across the various hosts.