FIFO_OVERRUN Interface Errors On PA-800 Series

• Seeing FIFO_OVERRUN counter increase on an interface

admin@pa> show system state filter sys.s1.p2.detail | match fifo 
sys.s1.p2.detail: { 'pkts1024tomax_octets': 0x338300d10, 'pkts128to255_octets': 0x38db5149, 
'pkts256to511_octets': 0x24eddd47, 'pkts512to1023_octets': 0x20f8656d, 
'pkts64_octets': 0x1072a6a19, 'pkts65to127_octets': 0x1293ec46d, 'rcv_fifo_overrun': 0x68bb9, }

• Network monitoring tool does not indicate bursty traffic on interface

• PA-800 series 
• PanOS 8.0.7+

• It is an intermittent congestion condition caused by paused frames on firewalls where flow control was enabled on adjacent firewalls.

1. Upgrade the PAN-OS versions to PAN-OS 8.1.10 or higher or 9.0.4 and higher versions.
2. Once Upgraded, Run the command below

> set system setting hol-system enable

• PAN-101613