Configuration Guide User guide

FastIron Configuration Guide 723
53-1002494-02
Dynamic link aggregation
Flexible trunk eligibility
The criteria for trunk port eligibility in an aggregate link are flexible. A range of ports can contain
down ports and remain eligible to become an aggregate link.
By default, the device places the ports into 2-port groups, consisting of an odd-numbered port and
the next even-numbered port. For example, ports 1/1 and 1/2 are a 2-port group, as are ports 1/3
and 1/4, 9/1 and 9/2, and so on. If either of the ports in a 2-port group is up, the device considers
both ports to be eligible to be in an aggregate link.
Figure 68 shows an example of 2-port groups in a range of four ports on which link aggregation is
enabled. Based on the states of the ports, some or all of them will be eligible to be used in an
aggregate link.
FIGURE 68 2-port groups used to determine aggregation eligibility
Table 136 shows examples of the ports from Figure 68 that will be eligible for an aggregate link
based on individual port states.
TABLE 136 Port eligibility for link aggregation
Port group 1 Port group 2 Trunk eligibility
1/11/21/31/4
Link StateUpUpUpUp4-port
1/1 – 1/4
Up Up Up Down 4-port
1/1 – 1/4
Up Down Up Down 4-port
1/1 – 1/4
Up Up Down Up 4-port
1/1 – 1/4
Down Down Down Up 2-port
1/3 – 1/4
Up Down Down Down 2-port
1/1 – 1/2
Port1/1
Port1/2
Port1/3
Port1/4
Group 1
Group 2