SFP no link - need help debugginbg

RouterOS Beginner Basics
1

Hello,

hI recently bought a CR1009-8G-1S-1S+. I added a S-31DLC20D SFP module to connect my internet uplink.
The uplink provider confirmed that the uplink should be working with wavelength 1310 nm, single mode, 1GBit.

Unfortunately the webinterface shows “no link”. Firmware is 6.33 and I rebooted the device - still no link.

Please note that I do NOT get a value for sfp-rx-power in the webinterface or the following dump. Is that a hint that the fiber is not OK or is that conclusion invalid?

/interface ethernet monitor 9
name: sfp1
status: no-link
auto-negotiation: disabled
sfp-module-present: yes
sfp-rx-lose: yes
sfp-tx-fault: no
sfp-type: SFP-or-SFP+
sfp-connector-type: LC
sfp-link-length-9um: 20000m
sfp-link-length-50um: 550m
sfp-link-length-62um: 550m
sfp-vendor-name: Mikrotik
sfp-vendor-part-number: S-31DLC20D
sfp-vendor-revision: A0
sfp-vendor-serial: MT50617H2074
sfp-manufacturing-date: 15-06-24
sfp-wavelength: 1310nm
sfp-temperature: 50C
sfp-supply-voltage: 3.237V
sfp-tx-bias-current: 21mA
sfp-tx-power: -7.055dBm

Best regards,
Andre

2

Have you tried enabling auto-negotiation?

3

Hi,

the provider said that auto negotioation must be disabled.

But I was able to solve the problem:

I was thinking of changing the polarity, but the cable which I got from
my provider lacks that possibility. It looks like it is glued together.

Well, it WAS glued together - I broke it and plugged the LC connectors
into the SFP. Now guess what: the darn thing is up and running!

Am I too naive to expect a E2E test done by provider is reliable? Do I
have to expect to break the connector and switch the polarity so that I
can use that thing?

To answer my question:
If sfp-rx-power is not showing a value, it looks like there is a problem with the physical connection.
Change polarity or ask your provider to do that on his patchpanel (that would be the normal solution)

Greetz,
Andre