# Reference to InputDiscards



## smdb01us (Jul 22, 2021)

Howdy, I have been trying to find documentation on what a "InputDiscards" (from the output of sysctl) means for the bge interface driver with not much luck. Any reference that you can point me towards? To be clear, I would like to understand what this counter reflects, mbufs, CRC, l2 or l3 errors?

If it is not documented, that's fine, I just wanted to make sure I did not miss the reference. Thank you in advance!
Ivan


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## smdb01us (Jul 22, 2021)

I just realized from a different post that you can run sysctl with -d but, honestly, that does not clarify much:


```
sysctl -d dev.bge.0.stats.InputDiscards
dev.bge.0.stats.InputDiscards: Discarded Input Frames
```

Can I infer that because it says "frames" this is a L2 stat/counter?


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## Jose (Jul 22, 2021)

Maybe your NIC has a silicon bug:




__





						if_bge.c « bge « dev « sys - src - FreeBSD source tree
					






					cgit.freebsd.org


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## smdb01us (Jul 22, 2021)

Jose said:


> Maybe your NIC has a silicon bug:
> 
> 
> 
> ...


Great information, thank you!


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## smdb01us (Sep 4, 2021)

Bumping this in case someone has any information related to this. I still getting a small numbers of input discards. The error rate is absolutely minimal so performance is not being affected but… it annoys the crap out of me that it is the only machine out of the 3 I have that have the same onboard port with the same chipset (bcm57766) that has these discards. Not a l1 problem, changed ports on switch, cable, SFP (also tested on ports with no SFP). I have checked the src for bge and, unless I am missing something, that counter is increased based on registers from the chipset directly but I can’t find documentation on *what*  exactly the discard are. Like the saying goes “I gots to know!” 

hw: Mac Mini late 2014, onboard gig ethernet port, 1GB full duplex
FreeBSD: 13-STABLE, driver bge. (This was also happening on RELEASE).
machine is acting as a firewall with pf.


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