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

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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.
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Steve Ballantyne

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Posted 3 years ago

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JeremyClarkson

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Interesting to find out if other SFP modules work with Extreme Devices.
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Steve Ballantyne

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Well - according to my sales and sales engineering folks at Extreme, it *should* work!
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JeremyClarkson

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Yes i suppose they are correct after all they are all Ethernet.
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Joseph Burnsworth

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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
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Steve Ballantyne

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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.
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Joseph Burnsworth

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

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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".
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Grosjean, Stephane, Employee

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It should work. What kind of fiber do you use?
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Steve Ballantyne

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Ooops, answered this above! Tripp Lite 25M Duplex Multimode Fiber 62.5/125 Patch Cable LC/LC 82ft.
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Necheporenko, Nikolay, Employee

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Check SFP module eeprom with command: 
debug hal show optic-info eeprom port 49
in a case of retrieving error these transceiver does not report for GE Compliance.  As a result you cannot bring up or link the port.  This is most likely a sfp module issue.
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Steve Ballantyne

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Thanks for the hint. I am off site at the moment, and it takes a while to get up to where this switch is location. I am going to take a Raspberry Pi up there and put it on wireless, connected locally to the console port on the switch so I can do some remote troubleshooting. I will test this as soon as I can get it set up!
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Steve Ballantyne

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Here is the output from running the above command ...

X450G2-48p-G4.4 # debug hal show optic-info eeprom 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

eeprom: Total Size 128, Values in Hex
00 01 02 03 04 05 06 07 08 09
-----------------------------------
000: 03 04 07 00 00 00 01 00 00 00
010: 00 01 0d 00 00 00 37 1b 00 00
020: 43 49 53 43 4f 2d 41 56 41 47
030: 4f 20 20 20 20 20 00 00 17 6a
040: 51 46 42 52 2d 35 37 36 36 4c
050: 50 20 20 20 20 20 20 20 20 20
060: 03 52 00 dd 00 1a 00 00 41 47
070: 53 31 30 34 32 35 35 50 58 20
080: 20 20 20 20 30 36 31 30 31 38
090: 20 20 00 00 00 de 00 00 06 e9
100: 3a 30 b9 bc 95 a3 20 f6 1a 07
110: bd 02 5a 44 7f 00 00 00 00 00
120: 00 00 00 00 21 30 5c 5a

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Necheporenko, Nikolay, Employee

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According to AVAGO specification SFP module asserts TX_Fault with "1A" hex data at the byte 65. This could happens due to next reasons:

TX_FAULT
A laser fault or a low VCC condition will activate the transmitter fault signal, TX_FAULT, and disable the laser. A low signal indicates normal laser operation and a high signal indicates a fault. 

Eye Safety Circuit
Under normal operating conditions, the laser power will be maintained below the eye-safety limit. If the eye safety limit is exceeded at any time, a laser fault will occur and the TX_FAULT output will be activated.
 
So there is no restriction to use this module from switch side. 
Try to use another SFP as this module could be deffective.
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Steve Ballantyne

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Hello Nikolay, thanks for the research on this. I have ordered two 10051H modules (Extreme branded 1000BASE-SX SFP 220/550M) and I hope to have them soon. I don't have any other Cisco modules to test with to see if one is bad.

I do have a pair of Cisco GLC-SX-MMD modules. Which technically function the same way, but have more diagnostic abilities. I had tried using these modules early on my troubleshooting and I couldn't get a link with them either. I am really hoping that it's not the fiber cable itself! I guess we will see if my Extreme modules show up and don't work.  ;-)
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JeremyClarkson

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Any update?
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Steve Ballantyne

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Not really. I had to run copper between these two switches to keep things on schedule. I'm still waiting on my reseller to get my extreme modules ordered. Their main supplier didn't have any.