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Fibre Channel (SAN)

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New Contributor
Posts: 2
Registered: ‎03-11-2019

High RX Power

[ Edited ]

Hello,

 

I  saw some errors on an ISL-Port:

          frames      enc    crc    crc    too    too    bad    enc   disc   link   loss   loss   frjt   fbsy  c3timeout    pcs
       tx     rx      in    err    g_eof  shrt   long   eof     out   c3    fail    sync   sig                  tx    rx     err
  0:  338.9m 130.8m   8      8      8      0      0      0      7.4k 172      0      0      0      0      0    172      0      0
  1:    2.2g 922.4m   0      0      0      0      0      0      0    172      0      0      0      0      0    172      0      0
  2:    3.5g   1.2g   0      0      0      0      0      0      0    172      0      0      0      0      0    172      0      0
  3:    1.4g   1.1g   0      2      0      0      0      0      0    172      0      0      0      0      0    172      0      0

 

The disc c3 and c3timeout may caused by a rebooted storage device. But the enc out look curios.

So i checked the sfps with sfp show:

 

switchb20:admin> sfpshow 0
                                          Alarm                  Warn
                                    low         high       low         high
Temperature: 45      Centigrade      -5         85         0           75
Current:     7.398   mAmps           2.500      12.000     2.000       11.500
Voltage:     3290.1  mVolts          3000.0     3600.0     3130.0      3460.0
RX Power:    -13.6   dBm (43.8 uW)   31.6   uW  1258.9 uW  31.6   uW   794.0  uW
TX Power:    -2.8    dBm (524.0 uW)  126.0  uW  1258.9 uW  251.0  uW   794.0  uW

switchb20:admin> sfpshow 1
                                           Alarm                  Warn
                                    low         high       low         high
Temperature: 48      Centigrade      -5         85         0           75
Current:     7.428   mAmps           2.500      12.000     2.000       11.500
Voltage:     3277.0  mVolts          3000.0     3600.0     3130.0      3460.0
RX Power:    -3.2    dBm (473.5uW)   31.6   uW  1258.9 uW  31.6   uW   794.0  uW
TX Power:    -3.5    dBm (444.2 uW)  126.0  uW  1258.9 uW  251.0  uW   794.0  uW

switchb20:admin> sfpshow 2
                                           Alarm                  Warn
                                    low         high       low         high
Temperature: 48      Centigrade      -5         85         0           75
Current:     7.398   mAmps           2.500      12.000     2.000       11.500
Voltage:     3296.7  mVolts          3000.0     3600.0     3130.0      3460.0
RX Power:    -2.5    dBm (559.9uW)   31.6   uW  1258.9 uW  31.6   uW   794.0  uW
TX Power:    -2.8    dBm (524.0 uW)  126.0  uW  1258.9 uW  251.0  uW   794.0  uW

switchb20:admin> sfpshow 3
                                           Alarm                  Warn
                                    low         high       low         high
Temperature: 48      Centigrade      -5         85         0           75
Current:     7.428   mAmps           2.500      12.000     2.000       11.500
Voltage:     3338.6  mVolts          3000.0     3600.0     3130.0      3460.0
RX Power:    -2.6    dBm (545.0uW)   31.6   uW  1258.9 uW  31.6   uW   794.0  uW
TX Power:    -3.4    dBm (455.0 uW)  126.0  uW  1258.9 uW  251.0  uW   794.0  uW

The RX Power of  the sfp in port 0 is very high I think but i don't know where the problem is. Is it the SFP it self? The SFP at the remote site (The TX and RX Powers look normal there) or is it an cable?

Is it realy a Problem? Which RX/TX Power values are okay? I don't find the datasheet for the SFP in the internet.

I also see this at errdump:

2019/03/05-08:42:08, [C3-1014], 2919, CHASSIS, WARNING, DS_6510B,  Link Reset on Port S0,P0(0) vc_no=2 crd(s)lost=3 auto trigger.
2019/03/07-20:57:25, [AN-1010], 2923, FID 128, WARNING, switchb20, Severe latency bottleneck detected at E-Port 3.

trunkshow:

   0   0   010000   id    8G       Online      FC  E-Port  (Trunk port, master is Port  3 )
   1   1   010100   id    8G       Online      FC  E-Port  (Trunk port, master is Port  3 )
   2   2   010200   id    8G       Online      FC  E-Port  (Trunk port, master is Port  3 )
   3   3   010300   id    8G       Online      FC  E-Port  10:00:00:05:XX:XX:XX:XX "switchb22" (downstream)(Trunk master)

 

Do you have any Idea? The SFP PN is: 57-0000088-01

 

Regards

Wanted

Frequent Contributor
Posts: 99
Registered: ‎01-19-2018

Re: High RX Power

Perhaps you meant "low rx power". Because -13 is less than -3 and it is definitely really low. From my experience, you'd better first replace the SFP at the remote site. Especially because of crc_g_eofs. But if this wouldn't help, you might need to replace the local SFP and double check the entire optical path in between. BTW, do you have anything like WDM in there?
New Contributor
Posts: 2
Registered: ‎03-11-2019

Re: High RX Power

Hello Alexey,

 

thank you. Yes, i mean low rx power, that make sense.

I will try to replace the SFP at the remote site. We don't use WDM.

 

One last question I tried to disable the port with portdecom but the loss less feature is not activated at the remote switch. Is it possible to activate it while production is running (dlsset --enable –lossless) or will this impact the system/fabric/performance?

 

Regards Maximilian

Regular Contributor
Posts: 151
Registered: ‎03-20-2018

Re: High RX Power

Your highest value error is ENC_OUT. This, coupled with the low RX Power is almost always cable. Very rarely is it the SFP. It is curious that this counter isn't higher though, so the SFP can't be ruled out entirely.

 

 

Check cable seating on both ends by pushing it into the SFP first. If you hear a click, it wasn't fully engaged. If you don't hear a click, look for kinks in the cable. Also, if there are interim connections between the two switches, check those as well.

 

Regular Contributor
Posts: 151
Registered: ‎03-20-2018

Re: High RX Power

FYI, you can shorten what you are looking for with the following command:

 

sfpshow -all | grep -e Port -e Power

 

Note that the grep portion is case sensitive.

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