This article explains how to find the SFP for which i2c poll is failing.
Syslog messages as below seen on the device:
Mar 16 02:43:25 2021 re0.test fpc1 PQ3_IIC(WR): I/O error (i2c_stat=0xa3, i2c_ctl[1]=0xb0, bus_addr=0x51) Mar 16 02:43:25 2021 re0.test fpc1 I2C Failed device: group 0xa0 address 0x51 Mar 16 02:43:25 2021 re0.test fpc1 PQ3_IIC(WR): no target ack on byte 0 (wait spins 2)
These messages are seen when SFPs are being inserted or taken out of the port. In this scenario, you can ignore the messages if the timestamp correlates to the SFPs in/out timestamp.
If you the messages are scrolling continuously, it indicates there is a component for which the chassis is not able to read the i2c values . The i2c (inter-integrated circuits) is a serial communication mechanism in which states for various components are polled at regular intervals by the chassis.
Log into the FPC shell:
It is common to see a lot of messages scrolling on the FPC shell. If so, disable logging for this FPC telnet session:
Check the syslog message on the FPC:
Narrow down the SFP for which the i2c polls are failing by checking the sfp list. The command, 'show sfp list' returns the SFP index numbers which come in handy for the next set of commands:
'show sfp list'
show sfp list SFP Toolkit summary: wakeup count: 6725, debug: 0, periodic enabled: 1, diagnostics enabled: 1 thread: 0x470f5ba8, itable: 0x460eb438, itable iterator: 0, sem: 0x460f3d18 polling interval delay: 1000 ms, polling max cpu: 100 ms poll for diags every 3 wakeups , SFPs polled for diags last time: 24 last periodic CPU time: 101 ms, maximum periodic CPU time: 681 ms max SFPs to poll per interval: 0 SFP Toolkit syslog throttling parameters: period: 120 samples , disable threshold: 10, enable threshold 0 SFP periodic diagnostics polling count: 65535 diag Index Name Presence ID Eprom PNO SNO calibr Toxic ----- -------------- ---------- -------- ---------- ----------- ------- ------- 1 MIC(5/0)(0) Present Complete NON-JNPR 10131411125189 int Unknown 2 MIC(5/0)(1) Present Complete NON-JNPR 10131212207686 int Unknown 3 MIC(5/0)(2) Present Complete NON-JNPR H53T0180 EXT** Unknown 4 MIC(5/0)(3) Present Complete NON-JNPR 10131403042757 int Unknown 5 MIC(5/0)(4) Present Complete NON-JNPR 10131311262033 int Unknown 6 MIC(5/0)(5) Present Complete NON-JNPR 10131403042750 int Unknown 7 MIC(5/0)(6) Present Complete NON-JNPR GW1205155523 EXT** Unknown 8 MIC(5/0)(7) Present Complete NON-JNPR 10131704125003 int Unknown 9 MIC(5/0)(8) Present Complete NON-JNPR 10131211089186 EXT** Unknown 10 MIC(5/0)(9) Present Complete NON-JNPR 10131212249907 int Unknown 11 MIC(5/1)(0) Present Complete NON-JNPR 10131402172160 int Unknown 12 MIC(5/1)(1) Present Complete NON-JNPR H67P0120 EXT** Unknown 13 MIC(5/1)(2) Present Complete NON-JNPR 10131409205537 int Unknown 14 MIC(5/1)(3) Present Complete NON-JNPR 10131704205713 int Unknown 15 MIC(5/1)(4) Present Complete NON-JNPR 10131402211281 int Unknown 16 MIC(5/1)(5) Present Complete NON-JNPR 10131309141065 int Unknown 17 MIC(5/1)(6) Present Complete NON-JNPR 10131208079479 EXT** Unknown 18 MIC(5/1)(7) Present Complete NON-JNPR 10131308081039 int Unknown 19 MIC(5/1)(8) Present Complete NON-JNPR 10131704205758 int Unknown 20 MIC(5/2)(0) Present Complete NON-JNPR 10131402172059 int Unknown 21 MIC(5/2)(1) Present Complete NON-JNPR 10131301029206 int Unknown 22 MIC(5/2)(2) Present Complete NON-JNPR 10131311051807 int Unknown 23 MIC(5/2)(3) Present Complete NON-JNPR 10131311051803 int Unknown 24 MIC(5/2)(4) Present Complete NON-JNPR 10131211089526 EXT** Unknown 25 MIC(5/2)(5) Present Complete NON-JNPR 10131402071658 int Unknown 26 MIC(5/2)(6) Present Complete NON-JNPR 10131506101215 int Unknown 27 MIC(5/2)(8) Present Complete NON-JNPR H72P0399 EXT** Unknown 28 MIC(5/2)(9) Present Complete NON-JNPR 10131303055537 int Unknown 29 MIC(5/3)(0) Present Complete NON-JNPR 10131704205744 int Unknown 30 MIC(5/3)(1) Present Complete NON-JNPR 10131402071650 int Unknown 31 MIC(5/3)(2) Present Complete NON-JNPR 10131208079485 EXT** Unknown 32 MIC(5/3)(3) Present Complete NON-JNPR H67P1503 EXT** Unknown 33 MIC(5/3)(4) Present Complete NON-JNPR 10131311051907 int Unknown 34 MIC(5/3)(5) Present Complete NON-JNPR 10131506183659 int Unknown 35 MIC(5/3)(6) Present Complete NON-JNPR 10131212207729 int Unknown 36 MIC(5/3)(7) Present Complete NON-JNPR 10131311051954 int Unknown 37 MIC(5/3)(8) Present Complete NON-JNPR 10131403042732 int Unknown 38 MIC(5/3)(9) Present Complete NON-JNPR 10131301029081 int Unknown
The syslog on the FPC shell did indicate a failure to read the state for SFP in link 0, but did not specify the MIC.
Confirm the port:
show sfp <index> info
show sfp 1 info index: 0x01 sfp name: MIC(5/0) pic context: 0x62a344e8 id mem scanned: true linkstate: Up sfp_present: true sfp_changed: false i2c failure count: 0x0 diag polling count: 0x443 no diag polling from RE:0x1 run_periodic: false
show sfp 11 info index: 0x0B sfp name: MIC(5/1) pic context: 0x62c54428 id mem scanned: true linkstate: Up sfp_present: true sfp_changed: false i2c failure count: 0x3E9 << Non-zero i2c failure count. diag polling count: 0x3E8 no diag polling from RE:0x1
Reseat the SFP on this port and monitor the log messages. There is a possibility that during a MW, the SFP on this port was not properly inserted.
If i2c failures are still seen after the SFP reseat, swap the SFP with a working SFP of the same type and monitor the status.