Netgear switch (specifically GS724T) and LACP/Jumbo Frames

If you’ve got a Netgear Smart switch with the LAG feature (I’ve just got a GS724Tv3), *and* you use jumbo frames on your network, beware of a really nasty gotcha in the switch’s management interface.
When you enable Jumbo frames on the ports in the switch, you enable 9216 as the maximum frame size on all the ports and then set up the LAG.
What you must *also* do is, once the LAG is created, is to go back to the ports page, and hit the LAGS “page” (not exactly obviously signposted as such, but at the top of the ports table, above the “Description” header there’s a LAGS link. Click that, then enable 9216 bytes across the LAG that you created. This is the critical step, and means that although the ports were configured for 9216 byte packets, when the LAG was created it didn’t propagate this frame size to the LAG from both the ports.

If you find this and it helps, you’re welcome.
My Synology NAS (DS412+) works in link aggregation mode with jumbo frames enabled flawlessly, once I’d figured out that the LAG is created as a virtual port and you need to make the non-obvious adjustment.

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