Allied Telesis AT-S63 - Manual (Page 246)

Chapter 23: Ethernet Protection Switching Ring Snooping
246 Section III: Snooping Protocols
After creating the VLANs, you activate EPSR snooping by specifying the
control VLAN with the ENABLE EPSRSNOOPING command. The switch
immediately begins to monitor the VLAN for control messages from the
master switch and reacts accordingly should it receive EPSR messages
on one of the two ports of the VLAN.