3Com 3C17300-US - SuperStack 3 Switch 4226T, Implementation Manual

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30 C
HAPTER
2: O
PTIMIZING
B
ANDWIDTH
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The member link ports can have different port configurations within
the same aggregated link, that is, auto-negotiation, port speed, and
duplex mode. However, please note the following:
■
To be an active participant in an aggregated link the member link
ports must operate in full duplex mode. (If a member link port does
not operate in full duplex mode it can still be a member of an
aggregated link but it will never be activated.)
■
If ports of a different speed are aggregated together, the higher
speed links carry the traffic. The lower speed links only carry the
traffic if the higher speed links fail.
■
Member links must retain the same groupings at both ends of an
aggregated link. For example, the configuration in
Figure 4 will not
work as Switch A has one aggregated link defined whose member
links are then split between two aggregated links defined on Switches
B and C. Note that this illegal configuration could not occur if LACP is
enabled.
Figure 4 An illegal aggregated link configuration
To make this configuration work you need to have two aggregated links
defined on Switch A, one containing the member links for Switch B and
the other containing those for Switch C.
When using an aggregated link, note that:
■
To gather statistics about an aggregated link, you must add together
the statistics for each port in the aggregated link.
■
If you wish to disable a single member link of an aggregated link, you
must first physically remove the connection to ensure that you do not
lose any traffic, before you disable both ends of the member link
Switch A
Switch C
AL 1
Switch B
AL 2
AL 3
dua1730-0bAA03.book Page 30 Monday, July 11, 2005 11:14 AM