Allied Telesis AT-S63 - Manual (Page 346)

Chapter 29: Internet Protocol Version 4 Packet Routing
346 Section VII: Routing
AT-9408LC/SP AT-9424T/GB, and AT-9424T/SP Switches
The AT-9408LC/SP, AT-9424T/GB, and AT-9424T/SP Switches do not
support the IPv4 packet routing feature. They do, however, support a
limited version of some of the features.
Local Interface
You can create one routing interface to provide support for those
management features that require the switch to have an IP address.
Furthermore, the interface can be designated as the local interface so that
the switch can function as the master switch of an enhanced stack or for
remote Telnet, SSH, or web browser management. For further
information, refer to “Routing Interfaces and Management Features” on
page 342.
ARP Table
These switches also have an ARP table with a maximum capacity of ten
ARP entries. The table and entries are used by the AT-S63 Management
Software when it performs a management function that requires it to
communicate with another device on the network. An example would be if
you instructed the switch to ping another network device or download a
new AT-S63 image file or configuration file from a TFTP server.
The value of the ARP table is that it eliminates the need of the switch to
issue unnecessary ARP broadcast packets when performing some
management functions. This can improve the switch’s response time as
well as reduce the number of broadcast packets on your network.
There are two types of entries. One type is permanent. There is only one
permanent entry and it is used by the switch for internal diagnostics. It can
never be removed from the table.
The other type is a temporary entry, of which there can be up to nine. The
switch adds a temporary entry whenever its management software
interacts with another network device during a management function.
When you enter a management command that contains an IP address not
in the table, the switch sends out an ARP broadcast packet. When the
remote device responds with its MAC address, the switch adds the
device’s IP address and MAC address as a new temporary entry to the
table.
A temporary entry remains in the table only while active. An entry remains
active so long as it is periodically used by the switch for management
functions. If an entry is inactive for a defined period of time known as the
ARP cache timeout, it is automatically removed from the table. To adjust
this value, refer to the SET IP ARP TIMEOUT command. The default is
150 seconds. If the table becomes full, the management software
continues to add new entries by deleting the oldest entries.