Elvin,
I have included an KB Article for your reference "How to configure sharing (LAG) with LACP on Extreme switches:-
Please click on the below-mentioned Article:-
https://gtacknowledge.extremenetworks.com/articles/How_To/how-to-configure-sharing-LAG-LACP-in-Summi...
To verify, if the LACP PDUs are received from the peer device, execute the following command "show lacp counters" on the Extreme switch and check if the counters in column "RxOk" are incrementing.
We could also apply the following ACL in the ingress direction on the corresponding port and check the output of "show access-list counter".
I have also included the KB Article for your reference which shows you a sample output of "show lacp counters" and the ACL Policy file.
Please click on the below-mentioned Article:-
https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-verify-if-the-LACP-PDUs-are-receive...
Regards,
Sumeesh