Allied-telesis AT-8550SP User Manual download pdf (Page 39)

AT-8500 Series Fast Ethernet Switch Installation Guide

A Few Basics about Ethernet Switching

An Ethernet switch interconnects network devices, such as workstations,

printers, routers, and other Ethernet switches, so that they can

communicate with each other by sending and receiving Ethernet

frames.

MAC Address

Table

Every hardware device in your network has a MAC address and each

MAC address is unique. The address is assigned to a device by the

device’s manufacturer. For example, the network interface cards that

you install in your computers have a unique MAC address assigned to

them by the adapter manufacturers.

An AT-8500 Series Fast Ethernet Switch has a MAC address table capable

of storing up to 8,000 MAC addresses. The switch uses the table to store

the MAC addresses of the network end nodes connected to the ports,

along with the port number on which each address was learned.

A switch learns the MAC addresses of the end nodes by examining the

source address of each packet received on a port. It adds the address

and port on which the packet was received to the MAC table if the

address had not already been entered in the table. The result is a table

that contains all the MAC addresses of the devices that are connected to

the switch’s ports, and the port number where each address was

learned.

When the switch receives a packet, it also examines the destination

address and, by referring to its MAC address table, determines the port

on which the destination end node is connected. It then forwards the

packet to the appropriate port and on to the end node. This increases

network bandwidth by limiting each packet to the appropriate port

when the intended end node is located, freeing the other switch ports

for receiving and transmitting data.

If the switch receives a packet with a destination address that is not in

the MAC address table, it floods the packet to all the ports on the switch.

If the ports have been grouped into virtual LANs, the switch floods the

packet only to those ports which belong to the same VLAN as the port

on which the packet was received. This prevents packets from being

forwarded into inappropriate LAN segments, increasing network

security. When the destination an end node responds, the switch adds

its MAC address and port number to the table.

If the switch receives a packet with a destination address that is on the

same port on which the packet was received, it discards the packet

without forwarding it on to any port. Because both the source end node

and the destination end node for the packet are located on the same

port on the switch, there is no reason for the switch to forward the

packet.

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 113 114

Comments to this Manuals

No comments

Allied-telesis AT-8550SP User Manual Page 39

Comments to this Manuals

Related products and manuals for Computer hardware Allied-telesis AT-8550SP