pfSync Multicast question

[jamespedersen-brightpattern.com]

Hi,

The pfSense docs mention that pfsync uses multicast:

https://docs.netgate.com/pfsense/en/latest/highavailability/pfsync.html

Does pfsync use layer-2 multicast or layer-3 multicast? We want to be able to configure our switches to use pfsync properly.

Thank you,
James Pedersen