Allied Telesis AT-S63 - Manual (Page 549)

AT-S63 Management Software Command Line Interface User’s Guide
Section VII: Internet Protocol Routing 549
At the end of this overview are two examples that illustrate the sequence
of commands to implementing the features described in this chapter. You
can refer there to see how the commands are used in practice. The
sections are “Routing Command Example” on page 565 and “Non-routing
Command Example” on page 569.
In the following discussions, unless stated otherwise the term “remote
destination” refers to a network or subnet that is not directly connected to
the switch.
Supported
Switches
The packet routing feature is supported on the AT-9424Ts,
AT-9424Ts/XP, AT-9448T/SP, and AT-9448Ts/XP switches. The feature
is not supported on the AT-9408LC/SP, AT-9424T/GB, and
AT-9424T/SP switches. The latter switches do allow for one routing
interface to support those management functions that require an IP
address on the switch. For further information, refer to “Routing Interfaces
and Management Features” on page 560 and “AT-9408LC/SP AT-9424T/
GB, and AT-9424T/SP Switches” on page 563. For a complete list of
available AT-9400 Series switches, contact your Allied Telesyn sale
representative or visit our web site.
Routing
Interfaces
The IPv4 packet routing feature on the switch is built on the foundation of
the routing interface. An interface functions as a logical connection to a
subnet and allows the egress and ingress of IPv4 packets to the subnet
from other local and remote networks, subnets, and nodes.
Interfaces are an independent routing function. They are not dependent on
static routes or RIP to pass IPv4 traffic among themselves on a switch. A
switch automatically begins to route IPv4 packets among its local subnets
as soon as two or more interfaces have been defined on the device.
In order for a switch to route IPv4 traffic among it local subnets, there must
be a routing interface on each subnet. You create an interface by
assigning it a unique IP address of the subnet and indicating the VLAN
where the subnet resides.
Interfaces also function as anchor points for static routes. A static route
defines the next hop to a remote destination. To create a static route to a
remote destination, you add it to the interface on the switch where the next
hop to the remote destination is located.
Interfaces also act as anchor points for RIP. You can add RIP to the
interfaces so that the switch automatically learns routes to remote
destinations by sharing its routing information with the neighboring routers.
In some limited network topologies, you might be able to meet the routing
requirements of the IPv4 packets of your network with just routing
interfaces. This would assume, of course, that the switch is directly
connected to all of the networks or subnets of your network and that there
are no remote destinations that would require static routes or RIP.