The following are restrictions for your switch stack configuration:
Only homogenous stacking is supported, that is, a stack ofCisco Catalyst 9300 Series Switchesstack with onlyCisco Catalyst 9300 Series Switchesas stack members.
Cisco Catalyst 9300L Series Switches stack with only Cisco Catalyst 9300L Series Switches as stack members.
C9300-24UB, C9300-24UXB, and C9300-48UB switches can only be stacked with each other.
During a switchover, when the standby device syncs with the active device, the following log message is displayed on the console:
%SM-4-BADEVENT: Event 'standby_phy_link_up' is invalid for
the current state 'NO_NEIGHBOR': rep_lsl_rx Gix/x/x -Traceback=
Ignore this message. It does not have any functional or operational impact.
You cannot have a switch stack containing a mix of different license levels.