Is a switch managed with its IP address or its MAC address?

The MAC address is the unique hardware signature of each device. When the IP address is the identifier of each device inside a local network. 

managed switch is differentiated in a network using its IP address. 

An unmanaged switch will be recognised only based on its MAC address. 

Amphenol Ring switches are intermediate models, partially managed. Like unmanaged switches, they use MAC addresses to handle the network. 
Moreover, due to a proprietary network, they also offer some of the interesting management features, normally available with managed switches. 

Content réference
Ethernet Military Switch RES-SCE-AC-8US
Ethernet Military Switch RES-SCE-8MG
Ethernet Military Switch RES-SCE-12MG
Ethernet Military Switch RESMLAC-8US-CAPS
Ethernet Military Switch RESMLAC-8MG-CAPS
Ethernet Military Switch RESMLAC-8MG-CAPS F35
Ethernet Military Switch RESMLAC-28MG
Ethernet Military Switch RJSMLAC-8UG-CAPS
Ethernet Military Switch RJSML-8US1/8UG1
Ethernet Military Switch RJSML-MG7F3G