Allied Telesis AT-S63 - Manual (Page 551)

AT-S63 Management Software Command Line Interface User’s Guide
Section VII: Internet Protocol Routing 551
Interface Numbers
An interface must be assigned an interface number in the range of 0 to 15.
This range corresponds to the maximum number of interfaces permitted in
a VLAN. Interfaces in different VLANs on the same switch can have the
same interface number, but interfaces in the same VLAN must have
different numbers.
For instance, if a switch has four local subnets and each is in a different
VLAN, all of the interfaces could have the same interface number, such as
0. However, if two or more of the subnets reside in the same VLAN, the
routing interfaces for the subnets in the VLAN must be assigned different
interface numbers.
Interfaces numbers are only used for interface identification when there is
more than one subnet and routing interface in a VLAN. Consequently, the
sequence in which the interface numbers are used is not important.
IP Address and Subnet Mask
An interface must be a member of the local network or subnet where it will
function as the logical connection for routing IPv4 packets. As such, it
must be assigned a unique IP address and a subnet mask appropriate to
the network or subnet.
The IP address and subnet mask of an interface can be assigned
manually or supplied by a DHCP or BOOTP server on the network. To
obtain its IP configuration from a DHCP server, a routing interface must be
able to directly access the server. The AT-S63 management software
does not support the DHCP Relay Agent. Routing interfaces will not
forward DHCP client requests from DHCP clients, including other
interfaces on the same switch.
Additionally, when a VLAN contains more than one interface, only one of
the interfaces can obtain its IP address from a DHCP or BOOTP server.
The IP addresses for 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 are sharing the same VLAN, only one
interface can obtain its IP address from a DHCP or BOOTP server. The
other three must be configured manually.