CRS212 SFP ports with fiber and RJ45 SFPS (RJ45 does not works)

RouterOS General
1

Hello

In my few CRS212 switches does not works autonegotiations on fiber links if other side is not CRS212. Even with RB260 converter/switch it is not working. It works only if I will disable autonegotiation and choose the speed and duplex. Why??? SFPs are Optic’s SFP-S-3553LC20D

Second problem I have with these great swithes is an RJ45 SFP. It does not works at all. Autonegotiation does not works. Manually configured port shows that is is UP but no RX traffic (probably other side wait for the negotiation?).

Is there a way to get it working in auto mode ?

2

It’s a known thing with various vendors and switches - it’s not specifically related to MT. On gigabit Ethernet, auto negotiation negotiates a lot more than just speed & duplex. It’s more than likely one of these other things that is negotiated, that is failing (for example flow control) - and thus the link does not come up.

If auto negotiation works, great. If not, just force them to 1000/full. It’s not the end of the world. I’ve seen this across a multitude of switches and sfp modules to be honest.