what is the usual reason for drop on a fortiswitch

[sean3]

greetings all,

here is the topology. let's focus on the left part. MPLS router is a Cisco router, the left L2 switch connected to MPLS router is FortiSwitch (108F).

we occasionally lost MPLS connection, and we did see there are some input drops on port 2 (blue arrow pointing to it in the above diagram) of the FortiSwitch (left  L2 switch in the above diagram). see below screenshot.

vendor engineer recommended to replace the cable between the mpls router and the left L2 switch. Yes, of course we can do it, but may I know what's the common reason for input drops. MTU on MPLS router is 1500 by default, I don't think this is the problem.

Thanks a lot!

[AEK]

H

i Sean

Load can cause packet drop. But according to the output you don't have to worry since you have 0.0000001% packets dropped

[ebilcari]

The main reason that a switch drops packets are frames with CRC errors. Having a few packets will not affect network quality. You can have more information about the reason of the drops with the diagnose commands, like:

# diagnose switch physical-ports hw-counter show rx <int>

[sean3]

thanks ebillcari,

but the switch is not providing the option of hw-counter