The config mode for the DHCP server will allow multiple static mappings pointing to same IP address.
Example:
$ config [edit] # set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test1 ip-address '192.168.0.220' # set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test1 mac-address 'ff:ff:ff:ff:ff:ff' # set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test2 ip-address '192.168.0.220' # set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test2 mac-address 'dd:dd:dd:dd:dd:dd' [edit] # commit [edit] # run show config commands | grep Test set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test1 ip-address '192.168.0.220' set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test1 mac-address 'ff:ff:ff:ff:ff:ff' set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test2 ip-address '192.168.0.220' set service dhcp-server shared-network-name LAN subnet 192.168.0.0/24 static-mapping Test2 mac-address 'dd:dd:dd:dd:dd:dd'
Expected result: Commit should fail due to the duplicate address.