Find available vlans on a link

RouterOS General
1

At a customers site ISP delivers fiber in the basement. The fiber terminates in a switch controlled by ISP. I think they’re using vlan and their point with a switch rather than a media converter is that they could just configure another port at the switch in order to give a connection to a new customer in the same building. My customer rents the whole building so the ISP will not get any new customer here before my customer moves out. Hence all that switch does is to convert a tagged vlan on fiber to a untagged copper wire.

Problem is that power in this building is not stable. In the main technical room there is a USP that powers an RB3011, a server, switches and several wAP ac’s by PoE. But as the ISP switch is in the basement it is not powered by UPS, hence internet connection drops when building looses power. (All workers uses laptops, which essentially has a build in UPS.)

My idea is that if I move the RB3011 from the main floor to the basement, I could power it aswell by PoE from the main floor. Then I could plug the SFP from the ISP switch into the RB3011. I tried this once - didn’t get network, and plugged the SFP back into the ISP switch. I’m guessing the problem was that ISP uses vlan for the fiber, and I don’t know which vlan they use. How can I find out which vlan I should configure on the SFP?

(An other option to why I didn’t get network is that the SFP is incompatible with the rb3011. How can I tell if that’s the case?)

2

We’d have to know the model number of the SFP and preferably the model number of the ISP switch. That said the ISP could be doing a lot or not much at all on the switch. The best bet is to try to work with the ISP to solve the problem.

Alternatively you can always place a UPS in front of the ISP switch in the basement and be done with it.

3

The ISP switch is a Zyxel. I think the model number was 2210.
I didn’t pay attention to what was written on the sfp.

ISP say they wont support any other configuration that the one they have provided. So the options is either to do it by mikrotik configuration or get a second UPS.