the two MDS switchs will be a fabric when they are connected,one VSAN only have a active zoneset.now 2 MDS switchs have two zoneset ,one zoneset will be useless.
u can config ip dhcp excluded-address for every swtich . for example ip dhcp excluded-address 192.168.0.1 192.168.0.127 ;the other is ip dhcp excluded-address 192.168.0.128 192.168.0.254. the ip address can not conflict .u must be sure any one switch...