That firmware version is out of date, however updating may not resolve this. It dos fix some other issues, so you may still want to apply it. [URL]   What does show lacp protocol-state show? Can you try to create a LAG with 1Gb ports and see if it will pass LACP PDUs? Have you tried to reload the switch?
Hi,  I've connected two PowerConnect 5548 via the 10G interfaces and created a port channel. But one of the switches is not receiving LACP PDU (it is also not receiving LLDP PDUs) and therefore the LAG is not established. Creating a static LAG works. Both switches are configured equally.  interface tengigabitethernet1/0/1 channel-group 1 mode auto !interface tengigabitethernet1/0/2 channel-group 1 mode auto ! Switch1# show lacp statistics tengigabitethernet 1/0/1te1/0/1 LACP statistics:      LACP Pdus sent:                75      LACP Pdus received:            0Switch2# show lacp statistics tengigabitethernet 1/0/1te1/0/1 LACP statistics:      LACP Pdus sent:                90      LACP Pdus received:            45  Any hints on how to debug this? What could block the PDUs on Switch1? Thanks. 
PC 5548 not receiving LACP PDUs