H3C Technologies H3C SecPath F1000-E - Manual (Page 20)

4
Link aggregation modes
There are two link aggregation modes: dynamic and static. Dynamic link aggregation uses LACP and
static link aggregation does not. Table 4 compares the two aggregation modes.
Table 4 A comparison between static and dynamic aggregation modes
Aggregatio
n mode
LACP status on
member ports
Pros Cons
Static Disabled
Aggregation is stable. The
aggregation state of a member
port is not affected by its peer
ports.
A member port does not adjust its
aggregation state according to
that of its peer port. The
administrator must manually
maintain link aggregations.
Dynamic Enabled
The administrator does not need to
maintain link aggregations. The
peer systems maintain the
aggregation state of the member
ports automatically.
Aggregation is unstable. The
aggregation state of member ports
is susceptible to network changes.
In a dynamic link aggregation group:
• A Selected port can receive and send LACPDUs.
• An Unselected port can receive and send LACPDUs only if it is up and has the same class-two
configurations as the aggregate interface.
Aggregating Links in Static Mode
LACP is disabled on the member ports in a static aggregation group. You must manually maintain the
aggregation state of the member ports.
The static link aggregation procedure comprises:
• Selecting a reference port
• Setting the aggregation state of each member port
Selecting a reference port
The system selects a reference port from the member ports that are in the up state and have the same
class-two configurations as the aggregate interface.
The candidate ports are sorted by aggregation priority, duplex, and speed in this order: lowest
aggregation priority, full duplex/high speed, full duplex/low speed, half duplex/high speed, and half
duplex/low speed. The one at the top is selected as the reference port. If two ports have the same
aggregation priority, duplex mode, and speed, the one with the lower port number wins out.
Setting the aggregation state of each member port
After selecting the reference port, the static aggregation group sets the aggregation state of each
member port, as shown in Figure 2 .