Allied Telesis AT-S63 - Manual (Page 550)

Chapter 32: Internet Protocol Version 4 Packet Routing
550 Section VII: Internet Protocol Routing
Interface Names Many of the commands for the IPv4 packet routing feature have a
parameter for an interface name. An interface name consists of a VLAN
and an interface number, separated by a dash. The VLAN is designated
by “vlan” followed by the VLAN identification number (VID).
Here are several examples. The interface name for a VLAN with the VID
of 7 and an interface number of 0 is:
vlan7-0
The interface name for a VLAN with the VID of 28 and an interface number
of 2 is:
vlan28-2
The following is an example of a command that uses an interface name.
The example uses the ADD IP INTERFACE command to create a new
interface for a subnet in a VLAN with a VID of 28. The interface is
assigned an interface number of 0, an IP address of 149.44.22.22, and a
subnet mask of 255.255.255.0:
add ip interface=vlan28-0 ipaddress=149.44.22.22 mask
255.255.255.0
Static Routes
Before a switch can route IPv4 packets to a remote network or subnet, it
must have a route to the destination. You can explicitly define a route in
the form of a static route. The primary information of a static route is the IP
address of the remote destination and the address of the next hop to
reaching the destination.
A static route must be attached to a routing interface. Furthermore, the IP
address of the next hop in a static route and the IP address of the interface
must be members of the same subnet. Consequently, a static route must
be added to the interface that belongs to the same subnet as the next hop
in the route.
For example, assume a switch supported four subnets with four interfaces
named VLAN4-0, VLAN11-0, VLAN12-0, and VLAN12-1. To add a static
route to a remote destination that had as its next hop an IP address in the
subnet of the VLAN4-0 interface, you would need to specify the VLAN4-0
interface.
Fortunately, specifying the interface is optional. The switch can
automatically match the static route with its appropriate interface. The unit
examines the IP address of the next hop in the route and adds the route
automatically to the interface of the same subnet. If the switch does not
have an interface of the same subnet as the next hop in a route, the
system does not add the route and instead displays an error message.