MikroTik

Hello,

RB250GS running 1.6. I have port configured as a trunk, and it connected to a Cisco 3750G on the other end. Port is auto on both ends, 1000M negotiated.

Throughout the day the 3750 logs interface down and then right back up. I ran the TDR test from the 3750 and all checked out. The distance is < 100 feet, with a couple of jacks in the run. All cabling is newer, cat5e/cat6. Previous to the RB250GS I had a Trendnet 5 port gig switch connected to the same cable and the Cisco never logged port flaps.

Nothing much in diagnostics or logs to be had on the RB250 end of course.

For a test, I have temporarily connected another 3750G to the same exact cable and there have been no interface flaps at all. I have the RB250GS connected to a different port on the far end 3750 now via a 3 foot cable. No flaps there either.

Could this be a 'sensitivity' issue on the RB250GS ? I.e. it's less tolerant of cabling/crosstalk etc than the Cisco's ?

I may be able to borrow a Fluke tester from work and do a true certification.

I had this same issue but on my RB411GL, After consulting support, they instructed me to perform a netinstall of the latest firmware to ensure everything was a fresh install instead of an upgrade, and that fixed my port flapping issue, been 7 days and havent had an issue since. Maybe same issue with other boards?

Hmm, well SwOS is GUI only. I don't know if I can do a netinstall. I'll look around in the GUI but it's pretty limited.

I think I'll also experiment with some longer coiled cable, multiple couplers/jacks etc to see if I can reproduce with increased length and junctions.

It's been almost 24 hours now - and the other 3750 has been connected the whole time, and the RB250GS is also stable on the 3 foot cable.

I didnt realize it was SwOS, my mistake for not reading all the way through.