On 9/11/23 05:37, Michael S. Keller via Dng wrote:
> On 11/8/23 14:51, jeremy ardley via Dng wrote:
>>
>> On 9/11/23 03:56, Michael S. Keller via Dng wrote:
>>> My oldest Linux host has trouble with IPv6. Apparently it's the only
>>> host in my home network that does have trouble with it (of those
>>> that can do IPv6), and I've run out of ideas. All tests are in the
>>> same network - traffic does not cross into my ISP's area. The same
>>> symptom has persisted across two different switch/router combos -
>>> first an old Airport Extreme, now a TP-Link Deco XE75.
> >Try setting up a direct cable connection between the two devices
> >without a switch. That will eliminate the possibility of other
> devices >on the LAN causing the problem.
>
> What sort of interference are you positing, that would affect just
> this one host, and only with IPv6?
> _______________________________________________


There are several possibilities, but by just running a cable between
devices you can isolate the problem to the specific host/O/S components.

Example of interference from other systems could be QOS shaping, IPv6
address conflicts, hardware faults, security software. etc etc.

If the single cable shows the same faults you can then examine things
like MTU, /etc./sysctl.conf, net.ipv6.tcp_rmem, |net.ipv6.tcp_wmem, |and
look for differences from other systems without the problem.