Brocade TurboIron 24X Series Configuration Guide - Manual (Page 336)

302 Brocade TurboIron 24X Series Configuration Guide
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Virtual Switch Redundancy Protocol (VSRP)
FIGURE 19 VSRP priority
However, if one of the VRID ports goes down on one of the backups, that backup priority is reduced.
If the master priority is reduced enough to make the priority lower than a backup priority, the VRID
fails over to the backup.
Figure 20 shows an example.
FIGURE 20 VSRP priority recalculation
You can reduce the sensitivity of a VSRP device to failover by increasing its configured VSRP
priority. For example, you can increase the configured priority of the VSRP device on the left in
Figure 20 to 150. In this case, failure of a single link does not cause failover. The link failure
caused the priority to be reduced to 100, which is still equal to the priority of the other device. This
is shown in
Figure 21 .
VSRP
Master
VSRP
Backup
optional link
VSRP
Aware
VSRP
Aware
VSRP
Aware
F F F
B B B
Configured priority = 100
Actual priority = (100 - 0) * (3/3) = 100 Configured priority = 100
Actual priority = (100 - 0) * (3/3) = 100
X
VSRP
Backup
VSRP
Master
optional link
VSRP
Aware
VSRP
Aware
VSRP
Aware
Configured priority = 100
Actual priority = 100 * (2/3) = 67 Configured priority = 100
Actual priority = (100 - 0) * (3/3) = 100
B B B
F F F
Link down