I've noticed that some RB (e.g. RB1000, 600A) with RouterOS 3.30 reset ethernet from time to time. It shows as dropping all pppoe sessions and ospf neighbours.

The problem is fixed by installing ROS 3.28 (not tried 3.29).

I have a similar problem on 4.6 version.

5.0beta2 also has this problem. The last version without the problem is 3.28.

Currently I workaround this problem by creating a bridge with a single port. The bridge does not reset when its port goes down-up.

It would be great to get more detailed information, so we can test the same configuration on our lab.
1) What is the configuration of RouterBOARD 600?
2) How it is connected to the another device?
3) Is there any on the middle device between the router and the another device?
4) What kind of the device is on the other end?

Are you able to reproduce the same problem with another device connected in the place of RB600?

It would be great to get more detailed information, so we can test the same configuration on our lab.
1) What is the configuration of RouterBOARD 600?
2) How it is connected to the another device?
3) Is there any on the middle device between the router and the another device?
4) What kind of the device is on the other end?

Are you able to reproduce the same problem with another device connected in the place of RB600?

1) several of them. Some are pppoe servers, some plain routers, all run ospf
2) with a twisted pair cable to switch (cisco, planet, dlink)
3) no
4) switch (cisco, planet, dlink)

No, it only happens with RB (ros>=3.30). I beleave it is a software problem.

What are you seeing that indicates the ethernet has reset? We are troubleshooting an RB450G that drops all connected clients and want to see if possibly its the same issue.

I am seeing the I cant mac-ping through ethernet until I disable and reenable the ethernet port. Then it works. I am currently using 3.30.