Configuration notes, Layer 2 and layer 3 redundancy, Master election and failover – Brocade TurboIron 24X Series Configuration Guide User Manual

Page 334: Vsrp failover

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Brocade TurboIron 24X Series Configuration Guide

53-1003053-01

Virtual Switch Redundancy Protocol (VSRP)

Configuration notes

VSRP and 802.1Q-n-Q tagging are not supported together on the same device.

VSRP and Super Aggregated VLANs are not supported together on the same device.

VSRP does not work on a VLAN which has multicast enabled.

TurboIron X Series devices support VSRP awareness, and VSRP-aware security features.

Layer 2 and Layer 3 redundancy

You can configure VSRP to provide redundancy for Layer 2 only or also for Layer 3:

Layer 2 only – The Layer 2 links are backed up but specific IP addresses are not backed up.

Layer 2 and Layer 3 – The Layer 2 links are backed up and a specific IP address is also backed
up. Layer 3 VSRP is the same as VRRP-E. However, using VSRP provides redundancy at both
layers at the same time.

Layer 2 Switches support Layer 2 VSRP only. Layer 3 Switches support Layer 2 and Layer 3
redundancy. You can configure a Layer 3 Switch for either Layer 2 only or Layer 2 and Layer 3. To
configure for Layer 3, specify the IP address you are backing up.

NOTE

If you want to provide Layer 3 redundancy only, disable VSRP and use VRRP-E.

Master election and failover

Each VSRP device advertises its VSRP priority in hello messages. During master election, the VSRP
device with the highest priority for a given VRID becomes the master for that VRID. After master
election, the master sends hello messages at regular intervals to inform the backups that the
master is healthy.

If there is a tie for highest VSRP priority, the tie is resolved as follows:

Layer 2 Switches – The Layer 2 Switch with the higher management IP address becomes the
master.

Switches with management IP addresses are preferred over switches without
management IP addresses.

If neither of the switches has a management IP address, then the switch with the higher
MAC address becomes the master. (VSRP compares the MAC addresses of the ports
configured for the VRID, not the base MAC addresses of the switches.)

Layer 3 Switches – The Layer 3 Switch whose virtual routing interface has a higher IP address
becomes the master.

VSRP failover

Each backup listens for hello messages from the master. The hello messages indicate that the
master is still available. If the backups stop receiving hello messages from the master, the election
process occurs again and the backup with the highest priority becomes the new master.

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