Allied Telesis AT-S88 - Manual (Page 61)

AT-S88 Management Software User’s Guide
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Also note that a static trunk does not provide for redundancy or link
backup. If a port in a static trunk loses its link, the trunk’s total bandwidth is
diminished. Though the traffic carried by the lost link is shifted to one of the
remaining ports in the trunk, the bandwidth remains reduced until the lost
link is reestablished or you reconfigure the trunk by adding another port to
it.
Static Port Trunk Guidelines
Following are the guidelines for creating a static trunk:
ˆ Allied Telesis recommends using static port trunks between Allied
Telesis networking devices to ensure compatibility. While an Allied
Telesis device might be able to form a static trunk with a device from
another equipment vendor, there is the possibility that the
implementation of this feature on the two devices might not be
compatible, resulting in undesired switch behavior.
ˆ A static trunk can contain up to eight ports.
ˆ The ports of a static trunk must be of the same medium type. They can
be all twisted pair ports or all fiber optic ports.
ˆ The ports of a trunk can be either consecutive (for example Ports 5-9)
or nonconsecutive (for example, ports 4, 8, 11, 20).
ˆ Before creating a port trunk, examine the speed, duplex mode, flow
control, and back pressure settings of all of the ports that will be in the
trunk. Verify that the settings are the same for all ports in the trunk. If
these settings are not the same, then the switch will not allow you to
create the trunk.
ˆ After you have created a port trunk, a change to the speed, duplex
mode, flow control, or back pressure of any port in the trunk
automatically implements the same change on all the other member
ports.
ˆ A port can belong to only one static trunk at a time.
ˆ The ports of a static trunk can be untagged or untagged members of
the same VLAN.
The switch selects a port in the trunk to handle broadcast packets and
packets of unknown destination. The switch makes this choice based on a
hash algorithm, depending upon the source and destination MAC
addresses.