Allied Telesis AT-S39 - Manual (Page 85)

AT-S39 User’s Guide
85
The AT-S39 management software offers two load distribution methods.
They are:
❑ Source Address (SA) Trunking
❑ Source Address / Destination Address (SA/DA) Trunking
Let’s first take a look at the SA method. When a switch receives a packet
from a network node, it examines the destination address to determine
on which switch port, if any, the packet should be transmitted. If the
packet is destined for a port trunk, the switch then examines the source
address of the packet. If this is the first packet from the source node to
be transmitted over a port trunk, the switch assigns the source address
to one of the trunk links. All subsequent packets from the source node
are sent out the assigned data link of the trunk.
The switch assigns source addresses so as to evenly distribute the
addresses, or at least as much as possible, across all the ports of the
trunk. The intent is to try and ensure that all links in the trunk are utilized.
Here is an example. Figure 21 on page 86 shows two AT-8000 Series
Switches, an AT-8024 (Switch #1) and an AT-8024GB (Switch #2)
interconnected with a port trunk of three data links. The trunk on Switch
#1 consists of Ports 13 to 15 and on Switch #2 of Ports 1 to 3. The 10Base
and 100Base workstations are directing traffic to a server connected to
Switch #2. The server is connected to Switch #2 with a fiber optic Gigabit
Ethernet data link provided by a 1000Base fiber optic GBIC module in the
AT-8024GB switch.