just a little clarification on above post;
We have noted that with bad quality long cables more then 70 mtrs and POE.
One of the rb500’s was practically unpingable.
The long cable setting did not help much, however if we issue the below command after each reboot the router is ok.
/int ether set ether1 auto-negotiation=no speed 10Mbps
NB. this command has to be issued after each reboot, strange, but it works.
Stranger than that was our fix. We started powering the RBs with RF cable along time ago because of same problems with br230. The change to the power jack from the PoE fixed the problems we had.
Really ODD!