Cisco 2960S SFF8472-5-THRESHOLD_VIOLATION

zoom_cool

Hi

I am having a problem connecting a 3750X switch to 2960s by Multi Mode fibre here is the error message below anybody any ideas?

%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/26: Rx power high warning; Operating value: -2.7 dBm, Threshold value: -3.0 dBm.

Here is the tranceiver information

DS-THN-SW3#show interfaces transceiver
If device is externally calibrated, only calibrated values are printed.
++ : high alarm, + : high warning, - : low warning, -- : low alarm.
NA or N/A: not applicable, Tx: transmit, Rx: receive.
mA: milliamperes, dBm: decibels (milliwatts).

Optical Optical
Temperature Voltage Tx Power Rx Power
Port (Celsius) (Volts) (dBm) (dBm)

---

---

---

---

---

Gi1/0/26 25.2 3.31 -5.1 -28.5

moc moc a moc

Weird, I've seen power low warnings, but never power high. What transceivers are you using? Do you have other modules or switches you can test with?

Post up the results of 'show int g1/0/26 trans prop' or equivalent for both transceivers

heffsarmy

Stick a 5dB attenuator on RX leg

zoom_cool

Brand new out out of the pack Cisco GLC-LH-SMD both switches and SFP's and Fibre cables new

zoom_cool

heffsarmy wrote: »

Stick a 5dB attenuator on RX leg

Does it mean I have too strong RX signal

zoom_cool

I will run command show int g1/0/26 trans prop monday get output

heffsarmy

They are long long haul SFPs, either swap out for a short haul SFP or attenuate the Rx leg. The Rx power range on that SFP is -3 to -20dBm, its currenlty receiving on the hot side -2.7dBm, a 5dB or 10dB would do the trick.

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6577/product_data_sheet0900aecd8033f885.pdf

heffsarmy

zoom_cool wrote: »

Does it mean I have too strong RX signal

Yes

zoom_cool

heffsarmy wrote: »

They are long long haul SFPs, either swap out for a short haul SFP or attenuate the Rx leg. The Rx power range on that SFP is -3 to -20dBm, its currenlty receiving on the hot side -2.7dBm, a 5dB or 10dB would do the trick.

http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6577/product_data_sheet0900aecd8033f885.pdf

I have some SX SFP is that what you mean about short haul

heffsarmy

zoom_cool wrote: »

I have some SX SFP is that what you mean about short haul

SFPs are rated by the distance the signal can travel ie long haul, intermediate and short haul. Essentially you current SFP GLC-LH-SMD has a range of upto 10KM used with single mode fiber, this SFP is basically a hybrid as it can be used with multimode fiber if you have a special fiber patch, link below.The SX SFP are multimode SFPs, they have a much shorter range, 550m. To save yourself a headache swap the SFP out for the SX model and send your new SFP's back to were you bought them from or stick them on ebay.


http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html

zoom_cool

We have used these before with no issues and mode conditioning cable I will let you know how I get on thanks for your help.

heffsarmy wrote: »

SFPs are rated by the distance the signal can travel ie long haul, intermediate and short haul. Essentially you current SFP GLC-LH-SMD has a range of upto 10KM used with single mode fiber, this SFP is basically a hybrid as it can be used with multimode fiber if you have a special fiber patch, link below.The SX SFP are multimode SFPs, they have a much shorter range, 550m. To save yourself a headache swap the SFP out for the SX model and send your new SFP's back to were you bought them from or stick them on ebay.


http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_bulletin_c25-530836.html

zoom_cool

I have change over to a SX MMD SFP with Multi Mode and it works correctly. But I ask the Fibre installer and he said the distance is approx 300 Meters but on the Cisco website it says that the max span is 220 meters for that SFP over 62.5 Fiber which is what I have. Will it be OK?

heffsarmy

Check the lights levels on the SFP Rx leg of both switches, the range is 0dBm to -17dBm, if your well within the range you will be grand.

zoom_cool

heffsarmy wrote: »

Check the lights levels on the SFP Rx leg of both switches, the range is 0dBm to -17dBm, if your well within the range you will be grand.

This is what it is like on the other side looks good to me

Optical Optical
Temperature Voltage Tx Power Rx Power
Port (Celsius) (Volts) (dBm) (dBm)

---

---

---

---

---

Gi1/0/4 32.8 3.30 -5.7 -7.3

heffsarmy

There good light levels

zoom_cool

I want to thank both your help with the Cisco switch problem it was the Mode condition leads a bad batch which I received I am now using the LH SFP with no problems.

Thanks again.

heffsarmy

Niceone, it can be a headache when things don't work as they should.

prashantkharat

Hi

I am having a problem connecting a 3750X switch to 2960s by Multi Mode fibre here is the error message.

%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.

Here is the transceiver information

01#sh int gi1/0/8 transceiver
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
If device is externally calibrated, only calibrated values are printed.
++ : high alarm, + : high warning, - : low warning, -- : low alarm.
NA or N/A: not applicable, Tx: transmit, Rx: receive.
mA: milliamperes, dBm: decibels (milliwatts).

Optical Optical
Temperature Voltage Tx Power Rx Power
Port (Celsius) (Volts) (dBm) (dBm)

---

---

---

---

---

Gi1/0/8 34.8 3.27 -5.0 -22.8 --


01#sh int Gi1/0/8 transceiver properties
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
Name : Gi1/0/8
Administrative Speed: 1000
Administrative Duplex: full
Administrative Auto-MDIX: on
Administrative Power Inline: N/A
Operational Speed: 1000
Operational Duplex: full
Operational Auto-MDIX: off
Media Type: 1000BaseSX SFP

Can anyone advise me, how to fix this issue.

Thanks,
Prashant

heffsarmy

prashantkharat wrote: »

Hi

I am having a problem connecting a 3750X switch to 2960s by Multi Mode fibre here is the error message.

%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.
%SFF8472-5-THRESHOLD_VIOLATION: Gi1/0/8: Rx power low alarm; Operating value: -22.8 dBm, Threshold value: -21.0 dBm.

Here is the transceiver information

01#sh int gi1/0/8 transceiver
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
If device is externally calibrated, only calibrated values are printed.
++ : high alarm, + : high warning, - : low warning, -- : low alarm.
NA or N/A: not applicable, Tx: transmit, Rx: receive.
mA: milliamperes, dBm: decibels (milliwatts).

Optical Optical
Temperature Voltage Tx Power Rx Power
Port (Celsius) (Volts) (dBm) (dBm)

---

---

---

---

---

Gi1/0/8 34.8 3.27 -5.0 -22.8 --


01#sh int Gi1/0/8 transceiver properties
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
Name : Gi1/0/8
Administrative Speed: 1000
Administrative Duplex: full
Administrative Auto-MDIX: on
Administrative Power Inline: N/A
Operational Speed: 1000
Operational Duplex: full
Operational Auto-MDIX: off
Media Type: 1000BaseSX SFP

Can anyone advise me, how to fix this issue.

Thanks,
Prashant

Your just over the threshold . How far is the fiber run? Clean the fibers or swap them out, if that does not work you can get a tool to clean sfp otherwise swap them one at a time to isolate dodgy sfp.