vrrp

ipv6 <id>

advertise <interval>

authentication <password>

description <text>

holdtime <secs>

ipv6

no...

preempt

priority <level>

shutdown

tracking {interface|master-up-time|vlan|vrrp-master-state}

vlan <vlanid>

Description

This command configures the VRRP.

Syntax

Parameter

Description

Range

Default

id

Number that uniquely identifies the VRRP instance, also known as the VRID. This number should match the VRID on the other member of the redundant pair.

For ease in administration, you should configure this with the same value as the VLAN ID.

After you configure the VRID, the command platform enters VRRP mode. From here, you can access the remaining VRRP commands.

1-255

ipv6

Include this optional parameter to define a VRRP using an IPv6 address.

advertise

Specifies the time, in seconds, between successive VRRP advertisements sent by the current master.

Best practices are to use the default value.

1-60 seconds

1 second
(1s=1000ms)

authentication

Configure an optional password of up to eight characters to be used to authenticate VRRP peers in their advertisements.

The password must be the same on both members of the redundant pair.

The password is sent in plain-text and therefore should not be treated as a security measure. Rather, the purpose of the password is to guard against misconfigurations in the event that other VRRP devices exist on the same network.

Note: This parameter is supported only for IPv4.

8 characters

description

Configure an optional text string to describe the VRRP instance.

1-80 characters

holdtime <secs>

The VRRP virtual router does not begin listening to advertisements until the holdtime expires. If your deployment includes a VRRP master with preemption disabled and an uplink switch is running RSTP, a higher value will prevent the VRRP master from regaining the master state after it reboots.

The holdtime is disabled by default. If enabled without mentioning a time range, the holdtime will be configured to the default value, 45 seconds.

30-120 seconds.

Disabled

ip address

Configure the virtual IP address that will be owned by the elected VRRP master. Use the same IP address on each member of the redundant pair.

This IP address will be redundant - it will be active on the VRRP master, and will become active on the VRRP backup in the event that the VRRP master fails.

The IP address must be unique; the IP address cannot be the loopback address of the . Only IPv4 address formats are supported.

ipv6 address

Configure the virtual IPv6 address that will be owned by the elected VRRP master. Use the same IPv6 address on each member of the redundant pair.

This IPv6 address will be redundant - it will be active on the VRRP master, and will become active on the VRRP backup in the event that the VRRP master fails.

The IPv6 address must be unique; the IPv6 address cannot be the loopback address of the . Only IPv6 address formats are supported. Starting from 8.2.1.0, you can configure a unique local address as the VRRP IPv6 address on the and the .

no

Negates all configured VRRP parameters.

preempt

Preempt mode allows a to take over the role of master if it detects a lower priority currently acting as master.

Best practices are to use the default value to avoid excessive interruption to users or “flapping” if a problematic is cycling up and down.

disabled

delay

Delay value in seconds.

Specifying a value enables the delay timer. The timer is triggered when the VRRP state moves out of backup or init state to become a master. This is applicable only if router pre-emption is enabled.

When the timer is triggered, it delays the router for a specified period of time before taking over the master router. In the mean time, if there is an advertisement from another VRRP master (existing master), the router stops the timer and does not transition to master.

0-60 seconds

0

priority

Defines the priority level of the VRRP instance for the . This value is used in the election mechanism for the master.

A higher number specifies a higher priority.

The default priority setting is adequate for most networks.

100

1-255

shutdown

Administratively shutdown VRRP. When down, VRRP is not active, although the maintains the configuration information.

To start the VRRP instance, use no shutdown.

enabled (VRRP is down)

tracking

Alter the virtual router priority value.

interface {gigabitethernet <slot/module/port>}

{sub <value>}

 

Configures VRRP tracking based on Layer-2 interface state transitions. You can track a combined maximum of 16 VLAN and Layer-2 interfaces.

<slot/module/port> - Interface in <slot>/<module>/<port> format.

sub - Decreases the priority of the VRRP instance by the specified number. When the interface comes up again, the value is restored to the previous priority level. The combined priority and tracking vales cannot exceed 255. If the priority value exceeds 255, the displays an error message. Valid range is 0-255.

master-up-time <duration> add <value>

The VLAN tracking feature monitors how long the has been master for the VRRP instance.

duration - This value configures the number of minutes that must elapse before uptime tracking takes place. Valid range is 0-1440 minutes.

add - Instructs the to add the specified value to the existing priority level. The combined priority and tracking values cannot exceed 255. Valid range is 0-255. If the priority value exceeds 255, the displays an error message similar to the following - Error: Vrrp 30 priority + tracking value exceeds 255.

 

vlan <vlanid> {sub <value>}

Configures VRRP tracking based on VLAN state transitions.

You can track a combined maximum of 16 VLAN and Layer-2 interfaces.

sub - Decreases the priority of the VRRP instance by the specified amount. When the VLAN comes up again, the value is restored to the previous priority level. Valid range is 0-255. The combined priority and tracking values cannot exceed 255. If the priority value exceeds 255, the displays an error message.

vrrp-master-state <vrid> add <value>

Specifies the VRID to use for tracking the state of the VRRP .

add - Instructs the to add the specified value to the existing priority level. The combined priority and tracking values cannot exceed 255. Valid value is 0-255. If the priority value exceeds 255, the displays an error message similar to the following - Error: Vrrp 30 priority + tracking value exceeds 255

1-255

vlan

Specifies the VLAN ID of the VLAN on which VRRP will run.

1-4094

Usage Guidelines

Use this command to set parameters for VRRP on the . The default VRRP parameters can be left for most implementations.

You can use a combination of numbers, letters, and characters to create the authentication password and the VRRP description. To include a space in the password or description, enter quotation marks around the string. For example, to create the password Floor 1, enter “Floor 1” at the prompt.

To change the existing password or description, enter the command with a different string. The new password or description takes affect immediately.

To unconfigure the existing password or description, enter ““ at the prompt. If you update the password on one , you must update the password on the redundant member pair.

Interface Tracking

You can track multiple VRRP instances to prevent asymmetric routing and dynamically change the VRRP master to adapt to changes in the network. VRRP interface tracking can alter the priority of the VRRP instance based on the state of a particular VLAN or Layer-2 interface. The priority of the VRRP instance can increase or decrease based on the operational state of the specified interface. For example, interface transitions (up or down events) can trigger a recomputation of the VRRP priority, which can change the VRRP master depending on the resulting priority. You can track a combined maximum of 16 interfaces.

 

You must enable preempt mode to allow a to take over the role of master if it detects a lower priority currently acting as master

Example

The following command configures a priority of 105 for VRRP ID (VRID) 30:

(host) [mynode] (config) #vrrp 30

priority 105

The following commands configure VLAN interface tracking and assumes the following:

You have two , a primary and a backup.

The configuration highlights the parameters for interface tracking. You may have other parameters configured for VRRP.

Primary Configuration

Backup Configuration

vrrp 10

vlan 10

ip address 10.200.22.254

priority 105

preempt

tracking vlan 20 sub 10

 

vrrp 20

vlan 20

ip address 10.200.22.254

preempt

priority 105

tracking vlan 10 sub 10

 

vrrp 30

vlan 30

ip address 10.200.22.254

preempt

priority 105

tracking vlan 20 sub 10

vrrp 10

vlan 10

ip address 10.200.22.254

priority 100

preempt

tracking vlan 20 sub 10

 

vrrp 20

vlan 20

ip address 10.200.22.254

preempt

priority 100

tracking vlan 10 sub 10

 

vrrp 30

vlan 30

ip address 10.200.22.254

preempt

priority 100

tracking vlan 20 sub 10

If VLAN 20 goes down, VRRP 20 automatically fails over, VRRP 10 and VRRP 30 would drop their priority to 95, causing a failover to the backup . Once VLAN 20 comes back up, the restores the VRRP priority to 105 for all VRRP IDs and resumes the master VRRP role.

Command History

Release

Modification

8.0.0.0

Command introduced.

Command Information

Platforms

License

Command Mode

All platforms

Base operating system.

Config mode on .