A customer has a RB3011 as main router and running CAPsMAN. Ever since it was new, winbox has disconnected frequently. When I first configured it, the disconnects happend at randomish 30 minute intervals. I could reconnect immediately so it wasn't a big issue. Now this happens about every minute, and sometimes I have to wait upto 5 minutes before I can reconnect. While winbox is unable to login, everything else seems to work - until yesterday. Yesterday the RB3011 stopped all traffic frequently - independent of me being logged in to winbox or not. There was no throughput even between devices connected to the same switch chip. I rebooted the RB3011. At that point it had an uptime of 11days. The reboot solved the throughput issue, but winbox still disconnects every minute or so.

I'm not onsite, so my first thought was an unstable internet connection. So I started winbox on a virtual server onsite, and the same thing happens there - my rdp to the server is stable, but winbox running on the server disconnects. So the issue happens when connected on lan interface (lan ip), on wan interface (wan ip) and through pptp vpn (using the routers vpn ip). The vpn is stable, and winbox to the CAPs over pptp is stable.

Is this a know issue? Is there any logging the can be enabled to help figure out what's happening?
Versions: ROS 6.39.1, firmware 3.35

(And while I wrote the rest of this message the throughput issue reappeared.)

Try to connect by IP, NOT by MAC.

Winbox does not disconnect without a valid reason when connected via IP.

I keep multiple winbox instances running for weeks or even months without a single disconnect on multiple devices/archs (RB3011 included).

As th0massin0 mentioned you should use IP instead of MAC (if you connect by MAC) since MAC is not very reliable and it's mainly for initial configuration or troubleshooting (ie: you lost tcp/ip access to the device).

If you're using Windows OS, you may try to disable all power saving features for your network device in device manager. That helped me when i had same issue.

I replaced the box because within an hour after I posted this thread it got impossible to deal with. I couldn't even stay connected to the unit long enough to do a remote reboot - neither by winbox or telnet (from lan). As the problem got worse so fast, and also started to affect packets passing trough the switch chip only, I blame the hardware, not the config. However I'm not 100% sure, as this is the most complex vlan config I've ever done on a routerboard (excluding CRS models).

What worries me is that the new box also disconnected winbox a couple of times before I changed any config from the default. After loading the config, winbox has seemed stable, so I'm hoping this box will function for more than 7 weeks. I'm happy that the replacement box came with a PSU plug too short to stay connected. Hence I know the replacement is from a different batch. Now the new box is running same rOS and same config. At first sign of instability I'll disable STP and install latest rOS.

Next question: Why did AC in my car stop working soon after start of this 6 hour drive to replace this router? This was not my day!

I get constant disconnects to my RB3011 by both MAC and IP if I connect locally via my wifi access point. Cabled in I have no issues. Wifi connection has no loss and consistently low. Just an "oddity" I have observed.

Just an update:
The new 3011 (which actually is older than the old one) is stable running same config as the dead one. Winbox stayed connected for 40 hours over vpn, then power at my house went out an my internet connection dropped. Thats way better than the old 3011 managed when new. This was my first experience of an unstable routerboard. The few hardware problems I've had with routerboards earlier has been DOA (2), killed by lightning (3), killed by heat(1), or died after 6+ years in production environment (6). Thats pretty good statistics, considered I've configured a some hundreds of RB's since 2009.

(And my car ac has figured it will only work when taken in for diagnostics)