Both ends are back on autoneg at 1000 Mbps and stable; UDM SFP+2 restored to
autoneg True / setting_preference auto from the payload staged before the
original change. ~50 s of renegotiation, nothing rebooted.
The force failed progressively and I called it too early. Errors on the
ESH-Media side went 200 at link-up, 221 at 42 minutes, 416 by four hours, with
flapping the operator noticed before my soak had accumulated enough to raise
it. I read a two-minute flat window as a plateau and said so; a marginal link
declares itself over hours, not minutes.
Do not re-force this port. The cable is being replaced at the weekend and a
correctly-coded DAC negotiates 10G on its own.
vh
054c098777