Trying to simply set the clock automatically on this ‘smart managed’ network switch turned into a bit of a challenge. Whenever a time sync is attempted from the NTP server it would fail.
The T2600G-28TS switch simply doesn’t have a ‘default gateway’ setting but you can add a static route instead. I took a punt with the following settings. Sadly, this doesn’t work.
To provide a default-gateway behaviour, instead you need to use the value “0.0.0.0” for both destination and subnet mask.
With this static route added, our NTP request succeeds