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Cisco SFP not connecting, shows signal, but with a fault

Cisco SFP not connecting, shows signal, but with a fault

Steve_Ballantyn
Contributor
Hello,

I have an Extreme X450-G2-48P-GE4 which I am linking to a Cisco 3750 series switch using two Cisco SFP 1000base SX modules (GLC-SX-MM). I am running ExtremeXOS version 16.1.2.14. I have no link lights, and no errors in my logs.

When I pull a debug on the port it shows signal is present, but that there is a "TX fault". I have tried increasing the debounce to 150 and then to 900, and rebooted the switch several times --- but still no connection.

Does anyone have any ideas on what I can try? I have two Extreme brand SFP's on the way, but I am trying to get this connection up in a hurry as users are anxious to get into new office space.
* X450G2-48p-G4.14 # debug hal show optic port 49
Port 49
SFP or SFP+: SFP
Signal: present
TX Fault: yes
SFP/SFP+ Vendor: CISCO-AVAGO
SFP/SFP+ Part Number: QFBR-5766LP
SFP/SFP+ Serial Number: AGS104255PX
SFP/SFP+ Manufacture Date: 061018
SFP/SFP+ Type: SFP/SFP+
Connector: LC
GE Compliance: 1000BASE-SX
Wavelength: 850
Also, I am *assuming* that the physical cable is good. But I had better be sure that it's not before I have the company come out to run a new line.

16 REPLIES 16

Joseph_Burnswor
New Contributor III
Are these being linked directly or through a Fiber Interconnect panel? If through a Panel Interconnect, I would check to make sure that the lasers are not aligning with each other. I would verify that the lasers are lighting the receive side (No light side) of each SFP and not laser to laser

Yes, they are MMF SFP's. The cable is orange. The full description of the cable is "Tripp Lite 25M Duplex Multimode Fiber 62.5/125 Patch Cable LC/LC 82ft".

These are MMF SFP's correct? what color fiber are you using to connect them? Orange or yellow?

There is no panel in this connection. It's just one long fiber cable with LC ends. There appears to be light on both sides. I have also tried flipping one end (TX/RX), but it didn't have any effect.

JeremyClarkson
New Contributor
Interesting to find out if other SFP modules work with Extreme Devices.
GTM-P2G8KFN