PCS error reported on Brocade switch port with Rx and Tx well within the recommended range

Applies to

Brocade switches

Issue

• PCS errors observed on switch ports:

/fabos/cliexec/porterrshow :
          frames     enc    crc    crc    too    too    bad    enc   disc   link   loss   loss   c3timeout   pcs   uncor
       tx     rx     in    err    g_eof  shrt   long   eof     out   c3    fail    sync   sig    tx    rx     err    err         

172:  276    165      0      3      2      0      0      1      0      0      2      0      2       0    0     89.7m   0

• Tx and RX power are well within the recommended range: 

=============
Slot  5/Port 28:
=============
RX Power:    -6.9    dBm (689.9uW) ​​​​​​
TX Power:    -1.1    dBm (784.2 uW)

• Below troubleshooting steps can be tried for isolating the issue:

1. Reseat, clean the cable and SFP on either ends of the connectivity
2. Clear switch stats (statsclear and slotstatsclear), and observe the port (using porterrshow )
3. If any further increment on the pcs err counters, perform hardware fault isolation for cable and sfp by following below steps:

• In order to do fault isolation if the hardware, move the cable to next available port on the switch end and observe for any increments:
• If the issues follows on new port, replace the cable/patch panel and verify the port counters
• If the issue does not follow to the new port, then swap the SFP of the affected port with a good known working SFP and see if the errors subsides