Little helpful tidbit.
Setting up an LACP aggregate on an Extreme switch in the CLI is a piece of cake.
# enable sharing X grouping Y-Z lacp
Where X is the first or ‘master’ port in the aggregate, and Y-X are the ports that will be included in the aggregate. (Y should be the same as X in most cases).
Remember to save, and if your LACP partner on the other end is already configured, you’ll see that everything is up!