Configuration Guide User guide

638 FastIron Configuration Guide
53-1002494-02
VSRP
When you configure a track port, you assign a priority value to the port. If the port goes down, VSRP
subtracts the track port priority value from the configured VSRP priority. For example, if the you
configure a track port with priority 20 and the configured VSRP priority is 100, the software
subtracts 20 from 100 if the track port goes down, resulting in a VSRP priority of 80. The new
priority value is used when calculating the VSRP priority. Figure 54 shows an example.
FIGURE 54 Track port priority
In Figure 54, the track port is up. SInce the port is up, the track priority does not affect the VSRP
priority calculation. If the track port goes down, the track priority does affect VSRP priority
calculation, as shown in Figure 55.
FIGURE 55 Track port priority subtracted during priority calculation
VSRP
Master
VSRP
Backup
optional link
VSRP
Aware
VSRP
Aware
VSRP
Aware
F
F
F
B
B
B
Configured priority = 100
Track priority 20
Actual priority = (100 - 0) * (3/3) = 100
Configured priority = 100
Actual priority = 100 * (3/3) = 100
Track port
is up
X
VSRP
Backup
VSRP
Master
optional link
VSRP
Aware
VSRP
Aware
VSRP
Aware
Configured priority = 100
Track priority 20
Actual priority = (100 - 20) * (3/3) = 80
Configured priority = 100
Actual priority = 100 * (3/3) = 100
Track link
is down
B
B
B
F
F
F