Configuration Guide User guide

FastIron Configuration Guide 349
53-1002494-02
Hitless stacking
Figure 30 illustrates a hitless stacking switchover after the network administrator increases the
priority value for two of the stack members.
FIGURE 30 Scenario 3 – Hitless stacking switchover after a priority change
Not allowed because priorities do not match
Switchover
Failover
Standby 2 becomes the Active controller
without a reload
Not allowed because priorities do not match
Switchover
Failover
Standby 2 becomes the Active controller
without a reload
Not allowed because priorities do not match
Switchover
Failover
Standby 4 becomes the Active controller
without a reload
Not allowed because priorities do not match
Switchover
Failover
Standby 1 becomes the Active controller
without a reload
Not allowed because priorities do not match
Switchover
Failover
Standby 3 becomes the Active controller
without a reload
Priority 150 assigned to Unit 3 (Member 3)
Priority 200 assigned to Unit 4 (Member 4)
1
Active 1 (pri=100)
Standby 2 (pri=0)
Member 3 (pri=0)
Member 4 (pri=0)
1
Active 1 (pri=100)
Standby 2 (pri=0)
Member 3 (pri=150)
Member 4 (pri=200)
1
Active 1 (pri=100)
Standby 2 (pri=0)
Member 3 (pri=150)
Member 4 (pri=200)
1
Active 1 (pri=100)
Member 2 (pri=0)
Member 3 (pri=150)
Standby 4 (pri=200)
1
Standby 1 (pri=100)
Member 2 (pri=0)
Member 3 (pri=150)
Active 4 (pri=200)
1
Member 1 (pri=100)
Member 2 (pri=0)
Standby 3 (pri=150)
Active 4 (pri=200)
The priority change triggers re-election
of the Active controller
Standby re-assigned
Switchover occurs
Standby re-assigned
120 sec.
30 sec.
30 sec.
Stage 1&2. Switchover
FCX stack formation
FCX stack priority change - Scenario 3
60 sec.