RB1100(AH) reboots, when I connect a Laptop

Hardware MikroTik hardware general
1

I’ve deployed many RB1100 and RB1100AHs in my network.
Sometimes it is necessary to visit a site and to connect a laptop for configuration purposes to the RB1100(AH).
Immediatelly after doing so, the Routerboard either reboots or freezes.
The freeze can only be solved by pulling the power cord.

It does NOT matter which RouterOS version is running on the RB1100(AH)s.
Also it does not matter which kind of laptop I plug in.

This behaviour is very annoying as it effectively stops all traffic passing the RB.

Even more strange the LEDs of the Ethernet Ports continue flickering even if the RB has frozen.
MAC-Telnet and Serial Console won’t work.

The log just shows:
system error critical
router rebooted without proper shutdown, probably power outage

This behaviour only appears when there is a certain (unknown) amount of uptime on the Routerboard.

2

First thing that comes to mind - Grounding.

3

The laptop itself isn’t grounded, because it is battery powered and isolated.

4

What kinds of laptops? also how is the RB1100 powered? I’ve got one RB1100 thats powered via PoE and it doesn’t go stupid when I plug a laptop into it. But its a Panasonic Toughbook

What happens if you hook it up through a separate PoE thats not powered up?

5

These RB1100 are powered by 230V. Grounding should be connected by the power cord as well as by the rackmount.

The used laptops are netbooks like eeePC-1000H or eeePC-1201HA. No GbE-Interface on these laptops.

So far I’ve not tried to use a PoE-Injector between Laptop and RB1100.

6

Does freezing/rebooting leaves any output on serial console? Does this router generate autosupout.rif?

7

Next time I visit a site, I’ll try to connect a serial cable to the router before I connect a Laptop.

What exactly do you mean by:
“Does this router generate autosupout.rif?”

I cannot connect to the router anymore once it has frozen.

8

Is there autosupout.rif file in files section when you log in to the router after it reboots.

9

Oh, I didn’t know this. Thanks :slight_smile:
I’ll have a look for it, when the sudden reboot happens again.

10

if there was a file after previous reboot, it will still be there, you can look now.

11

The File List of a router that rebooed suddenly two days ago is completely empty.