On 2023-11-10 19:38, Gregory Nowak via Dng wrote:
> On Fri, Nov 10, 2023 at 08:20:34AM -0600, Michael S. Keller via Dng wrote:
>> I did not have the opportunity to use the onboard NIC for this
>> point-to-point test, but with the USB network adapter, I saw no slowdowns on
>> a point-to-point link, while I did when it was connected to my greater home
>> network.
>
> Can you rule out the ethernet cable and the port on the switch the
> host is connected to? Do other machines have the same issue with the
> same ethernet cable or port? Can you try another ethernet cable and
> another port with the host having the problem?

The cable seems unlikely to be an issue, as IPv4 is fast, approaching
gigabit speeds. The cable has been changed since the symptom first
occurred, though not in a few months.

The symptom occurs with two different router/switch combos, both the old
Airport Extreme and the new TP-Link Deco.

>
>>
>> I saw no sign in syslog of an address conflict.
>
> Is the gateway which assigns IPv6 addresses to your network able to do
> some sort of logging? If yes, anything there regarding IPv6 for this
> client which doesn't show up for other clients?
>
> Greg
>
>

There is logging, but it doesn't appear to contain any notes on IPv6,
even at debug level. From the log, it looks like TP-Link may use some
variant of OpenWRT, as there is a sign that it contains the Luci
administration tool.

As for using Wireshark, I can see when a big transfer stalls, but am not
sure what useful bits to glean from the results. When a big Samba file
transfer stalls, I see IPv6 router advertisements and a bunch of other
stuff. Eventually there's a TCP reset, and soon after the file transfer
resumes.

-Michael