QFX5220-32CD

QFX5130-32CD

All 400G optical transceiver interface flapped at the same time.

400G Optical Transceivers on QFX5130-32C and QFX5220-32C have a nominal voltage drop of upto 2% .

Although this remains within specification, optical modules are rated for 3.3V +/-5%, meaning any reduction in operating voltage directly erodes noise margin.

 The link becomes more susceptible to transient noise events, which may manifest as simultaneous interface flaps.

https://prsearch.juniper.net/problemreport/PR1940885

Below commands output will be collected post executing below script. Please follow steps below

show chassis environment fpc | match VCC3V3------->Pre
show chassis environment fpc | match VCC3V3------->Post

Script-name >>>> i2cset_margin_plus_2.sh (File is attached in the related section.)

Step1: show chassis hardware >>>> to see the Transceiver type installed

Step2: show chassis environment fpc >>>> to get the voltage measurement

Step3: show interfaces diagnostics optics >>>> to see all the Voltage Levels for each Transceivers

Step4: Save the script i2cset_margin_plus_2.sh into /var/db/scripts/event folder

Step5: execute manually sh i2cset_margin_high_2.sh high

/var/tmp# sh ./i2cset_margin_plus_2.sh high

pcimem /sys/bus/pci/devices/0000:08:00.0/resource0 0x150 w 0x0

Execute again the two commands after execution to see the values reported.

show chassis environment fpc | match VCC3V3------->Post

Step6: show chassis environment fpc to get the voltage measurement

Step7: show interfaces diagnostics optics to see all the Voltage Levels for each Transceivers

Step8: archive of /var/log

To ensure settings are applied even after power cycle add below event-option.

set event-options policy test events hwd_fru_snmp_trap_notice

set event-options policy test within 1 trigger on

set event-options policy test within 1 trigger 1

set event-options policy test attributes-match hwd_fru_snmp_trap_notice.trap-message matches jnxFruOnline

set event-options policy test attributes-match hwd_fru_snmp_trap_notice.fru-name matches "/\Chassis\[0\]\/Chassis\[0\]"

set event-options policy test then execute-commands commands "request routing-engine execute command \"sh /var/db/scripts/event/i2cset_margin_high_2.sh\""

set event-options policy test then execute-commands output-format tex

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Note:To turn off the voltage margin with the following CLI command.

request routing-engine execute command "sh /usr/sbin/i2cset_margin.sh nominal"