# What causes mac_stats.checksum_errs



## Rudy (Aug 22, 2019)

Are the errors from the transmitting server/router/switch or are they related to issues on my ix card?  (Running FreeBSD 11.3 with about 3Gbps of traffic on a router):

```
# sysctl dev.ix | grep check ; sleep 1; sysctl dev.ix | grep check
dev.ix.3.mac_stats.checksum_errs: 50
dev.ix.2.mac_stats.checksum_errs: 62611005
dev.ix.1.mac_stats.checksum_errs: 50591972
dev.ix.0.mac_stats.checksum_errs: 29478560
dev.ix.3.mac_stats.checksum_errs: 50
dev.ix.2.mac_stats.checksum_errs: 62611192
dev.ix.1.mac_stats.checksum_errs: 50592139
dev.ix.0.mac_stats.checksum_errs: 29481409
```
ix3 doesn't have an IP address on it.


----------



## Phishfry (Aug 22, 2019)

Did you see these?
_



			changing from STP/RSTP to MSTP fixes the error.
		
Click to expand...

_





						X520-DA2, FreeBSD, rec_len_errs
					

Hello,  We have a FreeBSD server in one of our data centers that is accumulating rec_len_errs. Our network team says everything looks okay on the Omni switch to which it is attached. However, something is causing these errors and I have exhausted my bucket of expertise trying to track it down...



					forums.intel.com
				








						222979 – [ixgbe] mac_stats.checksum_errs falsely incrementing?
					






					bugs.freebsd.org
				




There is also the newest Intel drivers in ports: net/intel-ix-kmod/


----------



## Phishfry (Aug 22, 2019)

I have to wonder how you could have 50 checksum errors on an interface that is not configured.
Maybe link layer stuff? I think this is the switch settings or bad counters.


----------

