When configuring LACP on the Palo Alto Networks firewalls, if you are connecting to devices other than another Palo Alto Networks devices, use slow timers for LACP.

Switch is active. Palo Alto Networks firewall is passive. Transmission rate should be set to slow on both the firewall and the switch(s).

If on interface from the aggregate group is connected to one switch and other to 2nd switch and both the physical switches are virtually clustered into one, the switch will generate one system ID which would be virtual and will use it for LACP negotiation. The switch will not use a physical system ID since it will be two in numbers and each would be specific to each switch.

Log file is l2ctrld.log.