Hello everybody,

I open a topic for a problem I have with a customer. it is a problem never seen before, maybe some of you have some ideas or advice.
The routerboard is a 2011iLS. Randomly during the day all the ports link "down" and after a few seconds they go back "up". Then after a few seconds again down and then up. The problem can last a few minutes, but up to half an hour.
I installed the routerboard instead of an old Zyxel USG20. The network problem appeared before in fact, I put a mikrotik to get more details on the problem. Therefore it is excluded that it is a problem of the Routerboard.
Is it electrical interference? on a cable? or environmental? do you have any suggestions on any log topics to add or tests to do?

Here a piece of log, where I have no details other than the link down and up:
jul/21 11:09:33 interface,info ether1_wan link down
jul/21 11:09:33 interface,info ether2_corepla link down
jul/21 11:09:33 interface,info ether3_lan link down
jul/21 11:09:33 interface,info ether4_lan link down
jul/21 11:09:33 interface,info ether5_lan link down
jul/21 11:09:35 interface,info ether1_wan link up (speed 1G, full duplex)
jul/21 11:09:35 interface,info ether2_corepla link up (speed 100M, full duplex)
jul/21 11:09:35 interface,info ether3_lan link up (speed 1G, full duplex)
jul/21 11:09:35 interface,info ether5_lan link up (speed 100M, full duplex)
jul/21 11:09:36 interface,info ether4_lan link up (speed 1G, full duplex)
jul/21 11:09:51 interface,info ether1_wan link down
jul/21 11:09:52 interface,info ether2_corepla link down
jul/21 11:09:52 interface,info ether3_lan link down
jul/21 11:09:52 interface,info ether4_lan link down
jul/21 11:09:52 interface,info ether5_lan link down
jul/21 11:09:53 interface,info ether2_corepla link up (speed 100M, full duplex)
jul/21 11:09:53 interface,info ether5_lan link up (speed 100M, full duplex)
jul/21 11:09:54 interface,info ether1_wan link up (speed 1G, full duplex)
jul/21 11:09:54 interface,info ether3_lan link up (speed 1G, full duplex)
jul/21 11:09:55 interface,info ether4_lan link up (speed 1G, full duplex)
jul/21 11:10:11 interface,info ether1_wan link down
jul/21 11:10:12 interface,info ether2_corepla link down
jul/21 11:10:12 interface,info ether3_lan link down
jul/21 11:10:12 interface,info ether4_lan link down
jul/21 11:10:12 interface,info ether5_lan link down
jul/21 11:10:13 interface,info ether2_corepla link up (speed 100M, full duplex)

Other than replace the router, and the problems continued, what else have you done/tried?

What are the ports connected to? My first thought/guess is that all ports connect to the same switch, and that switch is acting up. All ports drop on the same second and return at the same second..

My first suggestion is to turn off auto-negotiation on all ports.

Is it electrical interference? on a cable? or environmental? do you have any suggestions on any log topics to add or tests to do?

It happens on all multiple ports, at the same time.. I'd be spending some time on-site to figure it out..

" tests to do"
Put a computer in the same room as the RouterBoard, with a known-good cable, see if it drops at the same time the other ports do,

I have a few ideas that I've seen cause this but without a LOT more information about the site, they are not even educated guesses, just random "gotcha events" I've seen before cause this..