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on 12-08-2014 03:46 PM
When using the commands from show controller <interface> an error can be reported that helps identify why the interface is not transmitting or receiving or coming up.
This is a bit of a bear doc maybe, but hopefully it explains some of the simple basics behind L1 related issues that can be identified with this command and what remedy to undertake to keep going.
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hi Xander
thanks for your sharing, this is Nan from CHINA TAC
customer wants to know the meaning of the following error message about signal failure detected and the possible cause to trigger the log, and what would happen after the log was generated.
LC/0/3/CPU0:Feb 27 11:33:48.445 : vic_0_2[366]: %PLATFORM-VIC-4-SIGNAL : Interface HundredGigE0/3/0/2, Detected Signal failure
is it a local fault or remote fault or both maybe ?

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HI Nan,
use this command and check the Tx/Rx.
show controllers HundredGigE0/3/0/2
You will find a lot of useful info there.
This is the output of a proper link (
Temperature: 27.656
Voltage: 3.295 Volt
Tx Bias: 4.964 mAmps
Tx Power: 0.61130 mW (-2.13746 dBm)
Rx Power: 0.53820 mW (-2.69056 dBm) --------> If RX power is way out of this range, then it's maybe a fault on the remote side.

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yeah to add to smail's Nan, the vic-signal error is basically a generic error that the optic has lost signal, this has a deeper laying reason, for instance the receive power is lost (no light) or that we experienced PCS or PHY errors. there is likely more syslog around it showing that the link or lane showed BER (bit errors) or something.
the following output below would be helpful to determine that.
at times this can be because of a dirty or faulty CPAK/optic. so trying a different optic, fiber, may be the cause of it. Also use the same optic/cable in a different port to see if it is the physical port or optic that is creeping up.
xander
sho controller HundredGigE0/9/0/7 phy PHY data for interface: HundredGigE0/9/0/7 Rx 64B66B Lane Sync PCS Virt PCS Service Block Marker Header Lane Lane Lane Lane Lock Sync Err Cnt BIP Errors Error Mapping -- --------- --------- ---------- ---------- ----- ------- 0 Locked Locked 0 0 Clean 1 1 Locked Locked 0 0 Clean 2 2 Locked Locked 0 0 Clean 4 3 Locked Locked 0 0 Clean 7 4 Locked Locked 0 0 Clean 8 5 Locked Locked 0 0 Clean 10 6 Locked Locked 0 0 Clean 13 7 Locked Locked 0 0 Clean 15 8 Locked Locked 0 0 Clean 17 9 Locked Locked 0 0 Clean 19 10 Locked Locked 0 0 Clean 0 11 Locked Locked 0 0 Clean 3 12 Locked Locked 0 0 Clean 5 13 Locked Locked 0 0 Clean 6 14 Locked Locked 0 0 Clean 9 15 Locked Locked 0 0 Clean 11 16 Locked Locked 0 0 Clean 12 17 Locked Locked 0 0 Clean 14 18 Locked Locked 0 0 Clean 16 19 Locked Locked 0 0 Clean 18 *** PHY PCS PMA Statistics *** Rx Rx Aligment PCS PCS Service Block Marker Lane Lane Lane Lock Lock BIP Errors Mapping ------- --------- --------- ---------- ------- 0 Locked Locked 5 10 1 Locked Locked 5 11 2 Locked Locked 5 0 3 Locked Locked 5 6 4 Locked Locked 5 5 5 Locked Locked 5 1 6 Locked Locked 5 12 7 Locked Locked 5 7 8 Locked Locked 4 16 9 Locked Locked 5 2 10 Locked Locked 5 14 11 Locked Locked 5 15 12 Locked Locked 5 19 13 Locked Locked 5 18 14 Locked Locked 5 17 15 Locked Locked 5 3 16 Locked Locked 5 8 17 Locked Locked 5 13 18 Locked Locked 5 4 19 Locked Locked 5 9
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Nan,
you can look into the "show controllers hu0/3/0/2 phy" to see what alerts are raised.
/Aleksandar
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really appreicated for all guys help.
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still have some questions
customer mentioned that there is a interface not down when detected SF. so is it possible?
what's the relationship between log Detected Signal failure / BER SF threshold / port down
I mean , must interface be down when SF log generate ? does the log generate only when BER SF over the threshold?

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correct, if the bit error rate is "bad enough" than the link will be declared down, this is seen what the thresholds are in the show controller <> phy also.
xander

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I had many times an issue with DWDM where I did a "shutdown" on one side and on the remote side the link was UP UP.
It's important that the DWDM team enables "loss forwarding" (term on
Not sure if your customer has this issue, Nan.
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hi all guys
thanks for your kindly help , customer is use 8x100G tomahawk LC.
maybe I didn't claim clearly in my previose message. sorry for that.
in fact customer observed that an error log
LC/0/3/CPU0:Feb 27 11:33:48.445 : vic_0_2[366]: %PLATFORM-VIC-4-SIGNAL : Interface HundredGigE0/3/0/2, Detected Signal failure
but they didn't observe that any down event or flap event of the intf hun0302.
customer wants to know whether the interface can still keep up even the SF has been detected?
if the interface would be down only when "bad enough", so is that mean in my case customer's link not bad enough ? because interface is not down. in other word, the log doesn't mean the SF rate exceed the threshold , any SF event will trigger the log. but only the event that rate exceed the threshold will trigger the interface down. Am I understand correct?
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Hey Xander,
Thanks for the details on 9k optic errors. Great information!
I have a question related to the vic errors on the 9k. Do you have additional details on what they may mean from the 9ks perspective? We have run into a few lately on 10G links transporting over optical networks. The confusing thing is when we see the RFI error the problem has been on the near side not the far side like the error would seem to indicate. Is there any logic in how the 9k determines an RFI?
In the example below we had a 10G link flapping between (2) ASR9k routers.
Near end 9k example (TXP problem occurs on the local link on this end):
LC/0/3/CPU0:Aug 8 06:37:14.712 : vic[369]: %PLATFORM-VIC-4-RFI : Interface TenGigE0/3/0/4, Detected Remote Fault
Far end 9k example
LC/0/3/CPU0:Aug 4 20:39:46.421 : vic[369]: %PLATFORM-VIC-4-SIGNAL : Interface TenGigE0/3/0/4, Detected Signal failure
Example of syslog when we actually unplug the fiber from the optic
LC/0/3/CPU0:Aug 4 20:40:06.786 : vic[369]: %PLATFORM-VIC-4-RX_LOS : Interface TenGigE0/3/0/4, Detected Rx Loss of Signal
Thanks,
Jon

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hi jon! htanks! :) ah you know VIC is the cisco specific driver that allowed us to use different phy implementations, like what you get when you are using MOD cards with MPA's. the VIC is a sort of abstraction layer that is the in between ether drivers and physical hardware.
in this case for your message, it is just the VIC reporting the L1 issues from the phy.
cheers!
xander
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Hi xthuijs,
We too face the same problem. how to overcome why do receiving the signal even if the physical port is up?