Interface errors

[tofaz]

Hi all,

this post is to share my experience with my current hardware and see if someone can help me out with the current issue that I am facing.

Here the info:

Hardware:

Brand: Protectli
Intel Quad Core Celeron J1900, 64 bit, 2.0GHz, 2MB L2 Cache
4x Intel Gigabit Ethernet NIC ports
4GB DDR3L RAM, 16GB mSATA SSD

Software: OPNsense 19.7.6

Internet connection: Fiber 500Mb/125Mb

Topology:
ISP ONT <--GETH--> Catalyst 3560G <--GETH--> OPNsense


Everytime I reach my top download speed I see the INerrors on the WAN interface increasing:

Name    Mtu     Network          Ipkts     Ierrs  Idrop    Opkts     Oerrs  Coll
em0    1500   <Link#1>       8157917  5362     0      3404088     0        0

But looking at top(1) I see that the CPU is used around 70% during the download test:

last pid: 17396;  load averages:  1.20,  0.99,  0.66                                                                                                up 0+10:44:02  09:27:29
50 processes:  1 running, 49 sleeping
CPU: 25.5% user,  0.0% nice, 43.6% system,  0.3% interrupt, 30.6% idle
Mem: 80M Active, 903M Inact, 474M Wired, 229M Buf, 2360M Free

Looking on the switch interface no errors are present:

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 2940000 bits/sec, 384 packets/sec
  5 minute output rate 10082000 bits/sec, 870 packets/sec
     290584 packets input, 243902590 bytes, 0 no buffer
     Received 2 broadcasts (0 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     686870 packets output, 980312212 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

I have swapped the patch cord from the switch to the FW but the issue persist and at this point I believe it is something related to the NIC drivers. I have run a test and the appliance can reach almost 1Gbps traffic (980Gbps).

If I test the traffic between the other interfaces I see the INerrors increasing on them as well.

Does any of you encountered the same issue or have any idea of what can cause the errors on the interface?

Thank you!