3Com SuperStack 3 3812 Implementation Manual page 26

26 C 2: O
HAPTER PTIMIZING
B
ANDWIDTH
If a member link in an aggregated link fails, the traffic using that link is
dynamically reassigned to the remaining member links in the aggregated
link. Figure 2 shows the simplest case: two member links, that is the
physical links, form an aggregated link. In this example, if link 1 fails, the
data flow between X and B is remapped to physical link 2. The
re-mapping occurs as soon as the Switch detects that a member link has
failed — almost instantaneously. As a result, aggregated link
configurations are extremely resilient and fault-tolerant.
Figure 2 Dynamic Reassignment of Traffic Flows
Switch
X
The key benefits of 802.3ad link aggregation are:
Automatic configuration — Network management does not need to
■
be used to manually aggregate links.
Rapid configuration and reconfiguration — Approximately one to
■
three seconds.
Compatibility — Non-802.3ad devices can interoperate with 802.3ad
■
enabled devices. However, you will need to manually configure the
aggregated links as LACP will not be able to automatically detect and
form an aggregation with a non-802.3ad device.
The operation of 802.3ad can be configured and managed via
■
network management.
A
Physical Link 1
Physical Link 2
Y
Switch
X
X
B
0
Y
A
X
B
1
B
Z
Aggregated Link