Allied Telesis AT-S63 - Manual (Page 305)

AT-S63 Management Software Features Guide
Section VII: Routing 305
the other interfaces in the same VLAN must be assigned manually. For
example, if there are four interfaces and each of their respective subnets
resided in a separate VLAN, then each interface can obtain its IP address
and subnet mask from a DHCP or BOOTP server. However, if the four
subnets share the same VLAN, only one interface can obtain its IP
address from a DHCP or BOOTP server. The other three must be
configured manually.