Allied Telesis AT-S63 - Manual (Page 318)

Chapter 27: Internet Protocol Version 4 Packet Routing
318 Section VII: Routing
Routing Interfaces and Management Features
Routing interfaces are primary intended for the IPv4 packet routing
feature. There are, however, a number of management functions that rely
on the presence of at least one routing interface on the switch to operate
properly. The switch uses the IP address of an interface as its source
address when performing the management function. The management
functions are listed here:
ˆ Network servers
ˆ Enhanced stacking
ˆ Remote Telnet, SSH, and web browser management sessions
ˆ Pinging a remote device
ˆ DHCP or BOOTP server
Network Servers
A local subnet on the switch must have an interface if the device is using
the subnet to access any of the following types of network servers:
ˆ SNTP server for setting the switch’s date and time.
ˆ RADIUS or TACACS+ authentication server for manager access
accounts and 802.1x port-based network access control.
ˆ Syslog server for storing events from the switch’s event logs.
ˆ TFTP server for uploading and downloading files to the switch.
The switch uses the IP address of the interface as its source address
when communicating with the network server. Without a routing interface
on the subnet, the switch will not have a source IP address to include in its
packets. For example, in order to set its date and time using an SNTP
server, the switch must have a routing interface on the local subnet from
where it is reaching the server.
The servers can be located on different routing interfaces on the switch.
For instance, the switch can access an SNTP server through one interface
and a RADIUS authentication server from another. This differs from some
of the earlier versions of the AT-S63 Management Software where all the
servers had to be members of what was referred to as the “management
VLAN.”
If you intend to use the IPv4 routing feature of the switch and assign
routing interfaces to all the local subnets and networks on a switch, this
requirement should not be a issue. However, if you choose not to use the
routing function and so not create interfaces or you have an AT-9400
Switch that only supports one interface, some planning will be necessary
in order to use these features. At a minimum, you must create one routing
interface on the switch and plan your network so that the switch can
access the servers from the subnet of the interface.