Allied Telesis AT-S63 - Manual (Page 127)

AT-S63 Management Software Menus Interface User’s Guide
Section I: Basic Features 127
manufacturer. For this reason static trunks are typically employed only
between devices from the same vendor. That is not to say that an Allied
Telesyn layer 2 managed switch cannot form a static trunk with a device
from another manufacturer; but there is the possibility that the
implementations of static trunking on the two devices might not be
compatible.
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 Telesyn recommends using static port trunks between Allied
Telesyn networking devices to ensure compatibility. While an Allied
Telesyn 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 the lowest number port that will
be in the trunk. Verify that its settings are correct for the device to
which the trunk will be connected. When you create a static port trunk,
the management software copies the current settings of the lowest
numbered port in the trunk to the other ports, because all ports in a
static trunk must have the same settings. For example, if you create a
port trunk consisting of ports 5 to 8, the parameter settings for port 5
are copied to ports 6, 7, and 8 so that all the ports of the trunk have the
same settings.
ˆ After you have created a port trunk, do not change the speed, duplex
mode, flow control, or back pressure of any port in the trunk without
making the same change to the other ports.
ˆ A port can belong to only one static trunk at a time.
ˆ A port cannot be a member of a static trunk and an LACP trunk at the
same time.
ˆ The switch can support up to six static trunks when LACP is disabled
and three static trunks when LACP is enabled.