Предварительный анализ показал, что зацепило только устройства на базе MT7615D (с DBDC), проблему пофиксили, выражаю благодарность за оперативный feedback.
M_Mikhail
Since 3.09, any Keenetic device use workaround for Full Duplex peer w/o AN mode:
Conditions:
- Keenetic side: port in AN mode
- Peer side: port in 10 or 100 w/o AN mode
Keenetic side will try second link-up in FD mode (see syslog). We assume that no longer exists real devices with 10 or 100 Mbps Half Duplex w/o AN.
This workaround usually need for ISP. If you have such devices, you can set Half Duplex mode w/o AN to desired Keenetic port.