And then tried to apply the configuration the A5120, however it doesn't work as described. I cannot enable jumbo frames on the individual interfaces (aggregation ports or gigabit) as the document says. When checking the online help in the CLI, the only place I can do so is immediately after switching to system-view I can do 'jumboframe enable'. However when I check the configuration I don't the setting anywhere so I have some doubts this command is doing what it suggests. Is there another way to check and confirm jumbo frames are turned on?
I have tested by pinging with various send buffer sizes and the dont fragment flag, and it appears jumbo frames is not enabled. However perhaps I am not doing it correctly.
I dont know about 5120SI but in 5120EI jumboframes are enabled by default.
This means that when you do "display current-configuration" it wont show anything regarding jumboframes because its default. Only interfaces with jumboframing disabled will show up with "undo jumboframe enable" in the configuration.
In order to verify if your interface allows jumbos or not you can do:
display interface GigabitEthernet 1/0/1
Which will have a line that informs you of current status:
