3Com 5500 SI - Switch - Stackable, Configuration Manual

Page: 451 / 686

MAC Address Table Management 451
3 Enter System View and download the switch.app from the TFTP server to the flash
memory of the Switch.
<SW5500> system-view
[SW5500]
4 Configure IP address 1.1.1.1 for the VLAN interface, ensure the port connecting the
PC is also in this VALN (VLAN 1 in this example).
[SW5500] interface vlan 1
[SW5500-vlan-interface1] ip address 1.1.1.1 255.255.255.0
[SW5500-vlan-interface1] quit
5 Upload the
config.cfg
to the TFTP server.
<SW5500> tftp 1.1.1.2 put config.cfg config.cfg
6 Download the
switch.app
from the TFTP server.
<SW5500> tftp 1.1.1.2 get switch.app switch.app
7 Use the
boot boot-loader
command to specify the downloaded program as the
application at the next login and reboot the Switch.
<SW5500> boot boot-loader switch.app
<SW5500> reboot
MAC Address Table
Management
A Switch maintains a MAC address table for fast forwarding packets. A table entry
includes the MAC address of a device and the port ID of the Switch connected to it.
The dynamic entries (not configured manually) are learned by the Switch. The Switch
learns a MAC address in the following way: after receiving a data frame from a port
(assumed as port A), the Switch analyzes its source MAC address (assumed as
MAC_SOURCE) and considers that the packets destined at MAC_SOURCE can be
forwarded using the port A. If the MAC address table contains the MAC_SOURCE,
the Switch will update the corresponding entry, otherwise, it will add the new MAC
address (and the corresponding forwarding port) as a new entry to the table.
The system forwards the packets whose destination addresses can be found in the
MAC address table directly through the hardware and broadcasts those packets
whose addresses are not contained in the table. The network device will respond after
receiving a broadcast packet and the response contains the MAC address of the
device, which will then be learned and added into the MAC address table by the
Switch. The consequent packets destined for the same MAC address can be
forwarded directly thereafter.