Allied Telesis AT-S63 - Manual (Page 143)

AT-S63 Management Software Menus Interface User’s Guide
Section I: Basic Features 143
❑ When you cable a trunk, the order of the connections should be
maintained on both nodes. The lowest numbered port in a trunk
on the switch should be connected to the lowest numbered port
of the trunk on the other device, the next lowest numbered port
on the switch should be connected to the next lowest numbered
port on the other device, and so on.
For example, assume that you are connecting a trunk between
two AT-9400 Series switches. On the first AT-9400 Series switch
you had chosen ports 12, 13, 14, 15 for the trunk. On the second
AT-9400 Series switch you had chosen ports 19, 20 21, and 22. To
maintain the order of the port connections, you would connect
port 12 on the first AT-9400 Series switch to port 19 on the second
AT-9400 Series switch, port 13 to port 20, and so on.
Port Operating
Specifications
The speed, duplex mode, and flow control settings must be the same for
all the ports of a port trunk. When you create a port trunk, the AT-S63
management software copies the current settings of the lowest
numbered port in the trunk to the other ports. For example, if you create
a port trunk consisting of ports 5 to 8, the speed, duplex mode, and flow
control settings for port 5 are copied to ports 6, 7, and 8 so that all the
ports of the trunk have the same settings. For this reason Allied Telesyn
recommends that before creating a port trunk you first examine the
settings of the lowest number port that will be in the trunk and verify
that it has the correct settings.
After you create a port trunk, do not change the speed, duplex mode or
flow control of any port in the trunk without making the same change to
the other ports.
Note
All ports in a trunk must operate at the same speed. When you
include twisted pair port 23R or 24R in a trunk and the port
transitions to redundant uplink status, the port speed is
automatically adjusted to 1000 Mbps. If the other ports in the trunk
are operating at a different speed, port trunking may be
unpredictable. Because of these port speed variables, Allied Telesyn
suggests that you not include twisted pair port 23R or 24R in a port
trunk.
Load
Distribution
Methods
There are two steps to create a port trunk. The first step is to identify the
ports on the switch that are to function as the port trunk. The second is
to select a load distribution method. This second step is important
because unless you select the correct distribution method for your
configuration, the switch might not evenly distribute the load across all
the links of a trunk, greatly diminishing the value of the port trunk.