Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 589)

Multi-Service IronWare Switching Configuration Guide 559
53-1003036-02
Layer 2 redundancy
16
MAC address failover on VSRP-aware devices
VSRP-aware devices maintain a record of each VRID and its VLAN. When the device has received a
Hello message for a VRID in a given VLAN, the device creates a record for that VRID and VLAN and
includes the port number in the record. Each subsequent time the device receives a Hello message
for the same VRID and VLAN, the device checks the port number:
• If the port number is the same as the port that previously received a Hello message, the
VSRP-aware device assumes that the message came from the same VSRP Master that sent
the previous message.
• If the port number does not match, the VSRP-aware device assumes that a VSRP failover has
occurred to a new Master, and moves the MAC addresses learned on the previous port to the
new port.
The VRID records age out if unused. This can occur if the VSRP-aware device becomes
disconnected from the Master. The VSRP-aware device will wait for a Hello message for the period
of time equal to the following:
VRID Age = Dead Interval + Hold-down Interval + (3 x Hello Interval)
The values for these timers are determined by the VSRP device sending the Hello messages. If the
Master uses the default timer values, the age time for VRID records on the VSRP-aware devices is
as follows:
3 + 2 + (3 x 1) = 8 seconds
In this case, if the VSRP-aware device does not receive a new Hello message for a VRID in a given
VLAN, on any port, the device assumes the connection to the Master is unavailable and removes
the VRID record.