New install on NUC12 - lots of missed packets and slow upload
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Mmm, nothing unusual there. Does
netstat -ishow drops or errors (or neither)? -
Yes it shows the same number under Ierrs for igc1, 0 under Idrop
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No other errors in the mac stat counters?
I normally expect 'missed packets' to be the result of no CPU cycles to service the queue but in a NUC I imagine it's massively over-powered. Hard to think it could exhaust anything at 1Gbps.
Since you're seeing only 70Mbps upload I'd check the basics, cable, ports at each end etc.
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I'll rule out the basics. I'll swap the LAN and WAN ports round too in case it's a hardware issue with the I226-V (which is a NUC expansion board).
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We have flow-control enabled by default for the i226-V NICs in the 4200. I would try enabling it.
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@stephenw10 Interesting results! I've enabled flow control on the unifi switch and the errors have disappeared, and upload is now full speed. Changing flow control on pfSense has no affect whatsoever so I guess I will leave it as default. I've also found I can't change flow control for the 2 interfaces independently, I wanted to disable for igc0 (WAN) and enable for igc1 (LAN) but having just one (e.g. dev.igc.0.fc 0) disables it for both.
@stephenw10 thank you for the suggestion!
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@mtis @stephenw10 Just been following this out of curiosity since I've got a box with I226-V NICs as well, although I disabled flow control on them. It's only been running for a month or two but gets heavy usage, and I haven't seen any errors like this. Is there a particular reason that flow control is enabled for the 4200? I wish I could remember what/where I read that disabling it might be a good idea . . .
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It's enabled by default on all our devices. That usually doesn't make much difference but it's really dependent on what it's connected to. Some things require it be enabled or disabled to get best performance.
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@stephenw10 Makes sense, thank you!
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Yes I’m not really clear why I need it enabled. I have 1GbE on all links, WAN to ISP ONT, LAN to switch, and then all devices connected to the switch. Why do I need flow control for this? I never needed it with OpenWrt.
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I’m worried that enabling flow control is masking the symptom but not resolving the underlying issue itself. Is it possible there is a bigger problem here, or is flow control sometimes required in a setup like this.
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@mtis I would defer to those more knowledgeable than myself on the subject, but from what I can tell, if enabling it got rid of the errors you were getting and did not introduce any other unexpected issues like reduced throughput, I probably wouldn't worry about it. Most of the advice I could find about whether to enable flow control or not seemed to just boil down to "try it both ways and see which works best for you", which is deeply unsatisfying for those of us who enjoy understanding why one thing works better than another. But it seems that to get there in this case would require a much deeper level of understanding and/or analysis of your particular network topology than I am capable of, at least.
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The one thing it could be masking is that for some reason the LAN interface is unable to keep up with the rate the traffic is arriving. You would not expect that to be possible on a 1G link into a 2.5G NIC.
Check the the CPU usage graphs in Status > Monitoring. Is it ever getting close to 100%/
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Update from me. Something didn't feel right. And I found it. Intel ASPM. Once I disabled this on the NUC in BIOS settings everything worked as expected.
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Nice! Yeah we've seen ASPM cause all sorts of issues.
