Implementing VRRP

The Virtual Router Redundancy Protocol (VRRP) feature allows for transparent failover at the first-hop IP router, enabling a group of routers to form a single virtual router.

Feature History for Implementing VRRP

Release

Modification

Release 5.0.0

This feature was introduced.

Prerequisites for Implementing VRRP on Cisco IOS XR Software

You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Information About Implementing VRRP

To implement VRRP on Cisco IOS XR software , you need to understand the following concepts:

VRRP Overview

A LAN client can use a dynamic process or static configuration to determine which router should be the first hop to a particular remote destination. The client examples of dynamic router discovery are as follows:

  • Proxy ARP—The client uses Address Resolution Protocol (ARP) to get the destination it wants to reach, and a router responds to the ARP request with its own MAC address.

  • Routing protocol—The client listens to dynamic routing protocol updates (for example, from Routing Information Protocol [RIP]) and forms its own routing table.

  • IRDP (ICMP Router Discovery Protocol) client—The client runs an Internet Control Message Protocol (ICMP) router discovery client.

The drawback to dynamic discovery protocols is that they incur some configuration and processing overhead on the LAN client. Also, in the event of a router failure, the process of switching to another router can be slow.

An alternative to dynamic discovery protocols is to statically configure a default router on the client. This approach simplifies client configuration and processing, but creates a single point of failure. If the default gateway fails, the LAN client is limited to communicating only on the local IP network segment and is cut off from the rest of the network.

The Virtual Router Redundancy Protocol (VRRP) feature can solve the static configuration problem. VRRP is an IP routing redundancy protocol designed to allow for transparent failover at the first-hop IP router. VRRP enables a group of routers to form a single virtual router . The LAN clients can then be configured with the virtual router as their default gateway. The virtual router, representing a group of routers, is also known as a VRRP group.

For example, Basic VRRP Topology shows a LAN topology in which VRRP is configured. In this example, Routers A, B, and C are VRRP routers (routers running VRRP) that compose a virtual router. The IP address of the virtual router is the same as that configured for the interface of Router A (10.0.0.1).

Figure 1. Basic VRRP Topology
Basic VRRP Topology

Because the virtual router uses the IP address of the physical interface of Router A, Router A assumes the role of the IP address owner. As the IP address owner router, Router A controls the IP address of the virtual router and is responsible for forwarding packets sent to this IP address. Clients 1 through 3 are configured with the default gateway IP address of 10.0.0.1.

Routers B and C function as backup virtual routers. If the IP address owner router fails, the router configured with the higher priority becomes the IP address owner virtual router and provides uninterrupted service for the LAN hosts. When Router A recovers, it becomes the IP address owner virtual router again.


Note


We recommend that you disable Spanning Tree Protocol (STP) on switch ports to which the virtual routers are connected. Enable RSTP or rapid-PVST on the switch interfaces if the switch supports these protocols.


Multiple Virtual Router Support

You can configure up to 255 virtual routers on a router physical interface. The actual number of virtual routers that a router interface can support depends on the following factors:

  • Router processing capability

  • Router memory capability

  • Router interface support of multiple MAC addresses

In a topology where multiple virtual routers are configured on a router interface, the interface can act as a IP address owner for one or more virtual routers and as a backup for one or more virtual routers.

VRRP Router Priority

An important aspect of the VRRP redundancy scheme is VRRP router priority. Priority determines the role that each VRRP router plays and what happens if the IP address owner virtual router fails.

If a VRRP router owns the IP address of the virtual router and the IP address of the physical interface, this router functions as a IP address owner virtual router.

Priority also determines if a VRRP router functions as a backup virtual router and determines the order of ascendancy to becoming a IP address owner virtual router if the IP address owner virtual router fails. You can configure the priority of each backup virtual router with a value of 1 through 254, using the vrrp priority command.

For example, if Router A, the IP address owner virtual router in a LAN topology, fails, an election process takes place to determine if backup virtual Routers B or C should take over. If Routers B and C are configured with the priorities of 101 and 100, respectively, Router B is elected to become IP address owner virtual router because it has the higher priority. If Routers B and C are both configured with the priority of 100, the backup virtual router with the higher IP address is elected to become the IP address owner virtual router.

By default, a preemptive scheme is enabled whereby a higher-priority backup virtual router that becomes available takes over for the backup virtual router that was elected to become IP address owner virtual router. You can disable this preemptive scheme using the no vrrp preempt command. If preemption is disabled, the backup virtual router that is elected to become IP address owner router virtual router remains the IP address owner router until the original IP address owner virtual router recovers and becomes IP address owner router again.

VRRP Advertisements

The IP address owner virtual router sends VRRP advertisements to other VRRP routers in the same group. The advertisements communicate the priority and state of the IP address owner virtual router. The VRRP advertisements are encapsulated in IP packets and sent to the IP Version 4 multicast address assigned to the VRRP group. The advertisements are sent every second by default; the interval is configurable.

Benefits of VRRP

The benefits of VRRP are as follows:

  • Redundancy— VRRP enables you to configure multiple routers as the default gateway router, which reduces the possibility of a single point of failure in a network.

  • Load Sharing—You can configure VRRP in such a way that traffic to and from LAN clients can be shared by multiple routers, thereby sharing the traffic load more equitably among available routers.

  • Multiple Virtual Routers—VRRP supports up to virtual routers (VRRP groups) on a router interface, subject to the platform supporting multiple MAC addresses. Multiple virtual router support enables you to implement redundancy and load sharing in your LAN topology.

  • Multiple IP Addresses—The virtual router can manage multiple IP addresses, including secondary IP addresses. Therefore, if you have multiple subnets configured on an Ethernet interface, you can configure VRRP on each subnet.

  • Preemption—The redundancy scheme of VRRP enables you to preempt a backup virtual router that has taken over for a failing IP address owner virtual router with a higher-priority backup virtual router that has become available.

  • Text Authentication—You can ensure that VRRP messages received from VRRP routers that comprise a virtual router are authenticated by configuring a simple text password.

  • Advertisement Protocol—VRRP uses a dedicated Internet Assigned Numbers Authority (IANA) standard multicast address (224.0.0.18) for VRRP advertisements. This addressing scheme minimizes the number of routers that must service the multicasts and allows test equipment to accurately identify VRRP packets on a segment. The IANA assigns VRRP the IP protocol number 112.

Configuring VRRP

This section contains instructions for configuring VRRP for IPv4 and IPv6 networks.


Note


The VRRP virtual router id (vrid) has to be different for different sub-interfaces, for a given physical interface.


Configuring VRRP for IPv4 Networks

This section describes the procedure for configuring and verifying VRRP for IPv4 networks.

Configuration

Use the following configuration for configuring VRRP for IPv4 networks.


Note


Certain customizations (as mentioned) are recommended to control the behavior of the VRRP group on committing the VRRP configuration on the Router. If the following customizations are not configured, then the Router seizes control of the VRRP group, and immediately assumes the role of the IP address owner virtual Router.


/* Enter the interface configuration mode and configure an IPv4 address for the interface. */
Router(config)# interface gigabitEthernet 0/0/0/1
Router(config-if)# ipv4 address 10.10.10.1 255.255.255.0
Router(config-if)# no shut
Router(config-if)# commit
Fri Dec  8 13:49:24.142 IST
Router:Dec  8 13:49:24.285 : ifmgr[402]: %PKT_INFRA-LINK-3-UPDOWN : Interface GigabitEthernet0/0/0/1, changed state to Down 
Router:Dec  8 13:49:24.711 : ifmgr[402]: %PKT_INFRA-LINK-3-UPDOWN : Interface GigabitEthernet0/0/0/1, changed state to Up 

Router(config-if)# exit
Router(config)# do show ip int brief                 
Fri Dec  8 13:50:05.505 IST

Interface                          IP-Address         Status             Protocol    Vrf-Name
GigabitEthernet0/0/0/0             unassigned         Shutdown           Down        default 
GigabitEthernet0/0/0/1          10.10.10.1         Up                 Up          default
GigabitEthernet0/0/0/2             unassigned         Shutdown           Down        default 
GigabitEthernet0/0/0/3             unassigned         Shutdown           Down        default 
GigabitEthernet0/0/0/4             unassigned         Shutdown           Down        default 


/* Enter the VRRP configuration mode and add the configured interface. */ 
Router(config)# router vrrp
Router(config-vrrp)# interface GigabitEthernet 0/0/0/1

/* CUSTOMIZATION: Configure a delay for the startup of the state machine when the interface comes up. */
Router(config-vrrp)# delay minimum 2 reload 10 */

/* Configure VRRP version 3 for IPv4 */
Router(config-vrrp-if)# address-family ipv4 vrrp 100 version 3       
Router(config-vrrp-virtual-router)# address 10.10.10.1

/* CUSTOMIZATION: Disable the installation of routes for the VRRP virtual addresses. */
Router(config-vrrp-virtual-Router)# accept-mode disable

/* CUSTOMIZATION: Set a priority for the virtual Router. */
Router(config-vrrp-virtual-Router)# priority 254

/* CUSTOMIZATION: Configure a preempt delay value that controls the selection of the IP address owner virtual Router. */
Router(config-vrrp-virtual-Router)# preempt delay 15

/* CUSTOMIZATION: Configure the interval between successive advertisements by the IP address owner virtual Router. */
Router(config-vrrp-virtual-Router)#timer 4

/* CUSTOMIZATION: Configure VRRP to track an interface. */
Router(config-vrrp-virtual-Router)# track interface GigabitEthernet0/0/0/1 30

 /* Commit the configuration */
Router(config-vrrp-virtual-Router)# commit
–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––-

You have successfully configured VRRP for IPv4 networks.

Validation

Use the following commands to validate the configuration.


/* Validate the configuration */
Router(config-vrrp-virtual-router)# do show run interface GigabitEthernet 0/0/0/1
Fri Dec  8 15:04:38.140 IST
interface GigabitEthernet0/0/0/1
 ipv4 address 10.10.10.1 255.255.255.0
!

–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––--
Router(config)# show running-config router vrrp
Fri Dec  8 13:50:18.959 IST
router vrrp
 interface GigabitEthernet0/0/0/1
   delay minimum 2 reload 10
  address-family ipv4
   vrrp 100 version 3
    priority 254
    preempt delay 15
    timer 4
    track interface GigabitEthernet0/0/0/2 30
    address 10.10.10.1
    accept-mode disable
   !
  !
 !
–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––--
Router(config-vrrp-virtual-router)# do show vrrp ipv4 interface gigabitEthernet 0/0/0/1
Fri Dec  8 15:02:56.952 IST
IPv4 Virtual Routers:
                      A indicates IP address owner
                      | P indicates configured to preempt
                      | |
Interface   vrID Prio A P State    Master addr     VRouter addr   
Gi0/0/0/1    100  255 A P Master   local           10.10.10.1     

––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––--
Router(config-vrrp-virtual-router)# end
Router# show vrrp detail
Fri Dec  8 15:08:36.469 IST
GigabitEthernet0/0/0/1 - IPv4 vrID 100
  State is Master, IP address owner
    1 state changes, last state change 01:19:06
    State change history:
    Dec  8 13:49:30.147 IST  Init     -> Master   Delay timer expired
  Last resign sent:     Never
  Last resign received: Never
  Virtual IP address is 10.10.10.1
  Virtual MAC address is 0000.5E00.0164, state is active
  Master router is local
  Version is 3
  Advertise time 1 secs
    Master Down Timer 3.003 (3 x 1 + (1 x 1/256))
  Minimum delay 1 sec, reload delay 5 sec
  Current priority 255
    Configured priority 100, may preempt
      minimum delay 0 secs

You have successfully validated VRRP for IPv4 networks.

Configuring VRRP for IPv6 Networks

This section describes the procedure for configuring and verifying VRRP for IPv6 networks.

Configuration

The following sample includes the configuration and customization of VRRP for IPv6 networks.


Note


Certain customizations (as mentioned) are recommended to control the behavior of the VRRP group on committing the VRRP configuration on the Router. If the following customizations are not configured, then the Router seizes control of the VRRP group, and immediately assumes the role of the IP address owner virtual Router.



/* Enter the interface configuration mode and configure an IPv6 address */
Router# interface GigabitEthernet 0/0/0/2
Router(config-if)# ipv6 address 10::1/64 
Router(config-if)# no shut

/* Exit the interface configuration mode and enter the vrrp configuration mode */
Router(config-if)# exit
Router(config)# Router vrrp

/* Add the configured interface for VRRP */
Router(config-vrrp)# interface GigabitEthernet 0/0/0/2

/* CUSTOMIZATION: Configure a delay for the startup of the state machine when the interface comes up. */
Router(config-vrrp)# delay minimum 2 reload 10 */

/* Enable the IPv6 global and link local address family on the interface  */
Router(config-vrrp-if)# address-family ipv6 vrrp 50
Router(config-vrrp-virtual-Router)# address linklocal autoconfig

/* CUSTOMIZATION: Disable the installation of routes for the VRRP virtual addresses. */
Router(config-vrrp-virtual-Router)# accept-mode disable

/* CUSTOMIZATION: Set a priority for the virtual Router. */
Router(config-vrrp-virtual-Router)# priority 254

/* CUSTOMIZATION: Configure a preempt delay value that controls the selection of the IP address owner virtual Router. */
Router(config-vrrp-virtual-Router)# preempt delay 15

/* CUSTOMIZATION: Configure the interval between successive advertisements by the IP address owner virtual Router. */
Router(config-vrrp-virtual-Router)#timer 4

/* CUSTOMIZATION: Configure VRRP to track an interface. */
Router(config-vrrp-virtual-Router)# track interface GigabitEthernet0/0/0/2 30

/* Commit the configuration */
Router(config-vrrp-virtual-Router)# commit

You have successfully configured VRRP for IPv6 networks.

Validation

Use the following commands to validate the configuration.

/* Validate the configuration */
Router(config-vrrp-virtual-router)# do show run interface GigabitEthernet 0/0/0/2
Fri Dec  8 14:55:48.378 IST
interface GigabitEthernet0/0/0/2
 ipv6 address 10::1/64
!
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––-
Router(config-vrrp-virtual-router)# do show running-config router vrrp
...
router vrrp
 interface GigabitEthernet0/0/0/2
  delay minimum 2 reload 10
  address-family ipv6
   vrrp 50
    priority 254
    preempt delay 15
    timer 4
    track interface GigabitEthernet0/0/0/2 30
    address linklocal autoconfig
    accept-mode disable
   !
  !
 !
!
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––-
Router(config-vrrp-virtual-router)# do show vrrp ipv6 interface gigabitEthernet 0/0/0/2
Fri Dec  8 14:59:25.547 IST
IPv6 Virtual Routers:
                      A indicates IP address owner
                      | P indicates configured to preempt
                      | |
Interface   vrID Prio A P State    Master addr     VRouter addr   
Gi0/0/0/2      50  254   P Master   local                         
                                               fe80::200:5eff:fe00:203

––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––-
Router(config-vrrp-virtual-router)# end
Router# show vrrp detail
Fri Dec  8 15:08:36.469 IST
GigabitEthernet0/0/0/2 - IPv6 vrID 50
  State is Master
    2 state changes, last state change 00:18:01
    State change history:
    Dec  8 14:50:23.326 IST  Init     -> Backup   Virtual IP configured
    Dec  8 14:50:35.365 IST  Backup   -> Master   Master down timer expired
  Last resign sent:     Never
  Last resign received: Never
  Virtual IP address is fe80::200:5eff:fe00:203
  Virtual MAC address is 0000.5E00.0203, state is active
  Master router is local
  
  Advertise time 4 secs
    Master Down Timer 12.031 (3 x 4 + (2 x 4/256))
  Minimum delay 2 sec, reload delay 10 sec
  Current priority 254
    Configured priority 254, may preempt
      minimum delay 15 secs
    Tracked items: 1/1 up: 0 decrement
      Object name                State     Decrement
      GigabitEthernet0/0/0/2        Up            30

You have successfully validated VRRP for IPv6 networks.

Clearing VRRP Statistics

Use the clear vrrp statistics command to clear all the software counters for the specified virtual router.

SUMMARY STEPS

  1. clear vrrp statistics [interface type interface-path-id [vrid ]]

DETAILED STEPS

Command or Action Purpose

clear vrrp statistics [interface type interface-path-id [vrid ]]

Example:



RP/0/RP0/CPU0:router# clear vrrp statistics 

Clears all software counters for the specified virtual router.

  • If no interface is specified, statistics of all virtual routers are removed.

MIB support for VRRP

VRRP enables one or more IP addresses to be assumed by a router when a failure occurs. For example, when IP traffic from a host reaches a failed router because the failed router is the default gateway, the traffic is transparently forwarded by the VRRP router that has assumed control. VRRP does not require configuration of dynamic routing or router discovery protocols on every end host. The VRRP router controlling the IP address(es) associated with a virtual router is called the IP address owner router, and forwards packets sent to these IP addresses. The election process provides dynamic fail over(standby) in the forwarding responsibility should the IP address owner router become unavailable. This allows any of the virtual router IP addresses on the LAN to be used as the default first hop router by end-hosts.The advantage gained from using VRRP is a higher availability default path without requiring configuration of dynamic routing or router discovery protocols on every end-host. SNMP traps provide information of the state changes, when the virtual routers(in standby) are moved to IP address owner router's state or if the standby router is made IP address owner router.

Configuring SNMP server notifications for VRRP events

The snmp-server traps vrrp events command enables the Simple Network Management Protocol (SNMP) server notifications (traps) for VRRP.

SUMMARY STEPS

  1. configure
  2. snmp-server traps vrrp events
  3. commit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure

Step 2

snmp-server traps vrrp events

Example:



RP/0/RP0/CPU0:router(config)snmp-server traps vrrp events 

Enables the SNMP server notifications for VRRP.

Step 3

commit

VRRP Support on PWHE Interfaces

Pseudowire Headend (PWHE) is a technology that allows termination of access pseudowires (PWs) into a Layer 3 (VRF or global) domain or into a Layer 2 domain. This feature enables you to configure VRRP on PWHE interfaces to provide redundancy between two routers that are connected through PWHE interfaces .

For more information about PWHE interfaces, see the chapter Implementing Multipoint Layer 2 Services of the L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers.

Configuration Example

To configure VRRP on PWHE interfaces, use the following steps:

  1. Enter the VRRP configuration mode.

  2. Configure a PWHE interface.

  3. Configure the VRRP address family for IPv4 and IPv6.

Configuration

/* Enter the VRRP configuration mode. */
Router# configure
Router(config)# router vrrp

/* Configure a PWHE interface. */
Router# (config-vrrp)# interface pw-Ether 1000

/* Configure the VRRP address family for IPv4 and IPv6. */
Router(config-vrrp-if)# address-family ipv4 vrrp
Router(config-vrrp-virtual-router)# address 172.16.0.0
Router(config-vrrp-virtual-router)# vrrp 1
Router(config-vrrp-virtual-router)# commit
Router(config-vrrp-address-family)# exit
Router(config-vrrp-if)# exit
Router(config-vrrp-if)# address-family ipv6 vrrp 1
Router(config-vrrp-virtual-router)# address global 2001:DB8::1
Router(config-vrrp-virtual-router)# address linklocal autoconfig
Router(config-vrrp-virtual-router)# commit

Running Configuration

router vrrp
 interface PW-Ether1000
  address-family ipv4
   vrrp 1
    address 172.16.0.0
   !
  !
  address-family ipv6
   vrrp 1
    address global 2001:db8::1
    address linklocal autoconfig
   !

Verification

Use the following command to verify the configuration of VRRP on PWHE interfaces:

Router# show run interface pw-ether 1000
interface PW-Ether1000
ipv4 address 172.16.0.0 255.255.255.0
ipv6 address 2001:DB8::1/125
attach generic-interface-list pwhe_vrrp
!

Use the following command to verify the details of VRRP configuration on PWHE interfaces:

Router# show vrrp  interface pw-Ether 1000 detail
PW-Ether1000 - IPv4 vrID 1
  State is Backup
    1 state changes, last state change 2d08h
    State change history:
    Nov 24 11:47:16.585 IST  Init     
  Last resign sent:     Never
  Last resign received: Never
  Virtual IP address is 172.16.0.0
  Virtual MAC address is 0000.5E00.0101, state is reserved
  Master router is 172.16.0.1, priority 100
  Version is 2
  Advertise time 1 secs
    Master Down Timer 3.609 (3 x 1 + (156 x 1/256))
  Minimum delay 1 sec, reload delay 5 sec
  Current priority 100
    Configured priority 100, may preempt
      minimum delay 0 secs

PW-Ether1000 - IPv6 vrID 1
  State is Backup
    1 state changes, last state change 2d08h
    State change history:
    Nov 24 11:47:19.600 IST  Init     
  Last resign sent:     Never
  Last resign received: Never
  Virtual IP address is 2001:DB8::1/125
    Secondary Virtual IP address is 2001:DB8:FFFF:FFFF:FFFF:FFFE:FFFF:FFFF
  Virtual MAC address is 0000.5E00.0201, state is reserved
  Master router is 2001:DB8::2
  Version is 3
  Advertise time 1 secs
    Master Down Timer 3.609 (3 x 1 + (156 x 1/256))
  Minimum delay 1 sec, reload delay 5 sec
  Current priority 100
    Configured priority 100, may preempt
      minimum delay 0 secs

Use the following command to verify VRRP state and priority of the current router:

Router# show vrrp  interface pw-Ether 1000        
IPv4 Virtual Routers:
                      A indicates IP address owner
                      | P indicates configured to preempt
                      | |
Interface   vrID Prio A P State    Master addr     VRouter addr  
PE1000         1  100   P Backup   172.16.0.1       172.16.0.0      
IPv6 Virtual Routers:
                      A indicates IP address owner
                      | P indicates configured to preempt
                      | |
Interface   vrID Prio A P State    Master addr                  VRouter addr  
PE1000         1  100   P Backup   2001:DB8::2    fe80::200:5eff:fe00:201

Hot Restartability for VRRP

In the event of failure of a VRRP process in one group, forced failovers in peer VRRP IP address owner router groups should be prevented. Hot restartability supports warm RP failover without incurring forced failovers to peer VRRP routers.

Configuration Examples for VRRP Implementation on Cisco IOS XR Software

This section provides the following VRRP configuration examples:

Configuring a VRRP Group: Example

This section provides the following configuration example of Router A and Router B, each belonging to three VRRP groups:

Router A:



config
interface tenGigE 0/4/0/4
ipv4 address 10.1.0.1/24
exit
router vrrp
interface tenGigE 0/4/0/4 
vrrp 1 priority 120
vrrp 1 text-authentication cisco
vrrp 1 timer 3
vrrp 1 ipv4 10..0.
vrrp 5 timer 30
vrrp 5 ipv4 10..0.
preempt disable
vrrp 100 ipv4 10..0.
commit

Router B:



config
interface HundredGigE 0/4/0/4
ipv4 address 10.1.0.2/24
exit
router vrrp
interface HundredGigE 0/4/0/4
vrrp 1 priority 100
vrrp 1 text-authentication cisco
vrrp 1 timer 3
vrrp 1 ipv4 10..0.
vrrp 5 priority 200
vrrp 5 timer 30
vrrp 5 ipv4 10..0.
preempt disable
vrrp 100 ipv4 10..0.
commit

In the configuration example, each group has the following properties:

  • Virtual Router 1:
    • Virtual IP address is 10. .0. .

    • Router A will become the IP address owner router for this group with priority 120.

    • Advertising interval is 3 seconds.

    • is .

    • is enabled.

  • Virtual Router 5:
    • is .

    • is .

  • Virtual Router 100:
    • Advertising interval is the default 1 second.

    • Preemption is .

    • is disabled.

Clearing VRRP Statistics: Example

The clear vrrp statistics command produces no output of its own. The command modifies the statistics given by show vrrp statistics command so that all the statistics are reset to zero.

The following section provides examples of the output of the show vrrp statistics command followed by the clear vrrp statistics command:



RP/0/RP0/CPU0:router# show vrrp statistics
show vrrp statistics
Invalid packets:
 Invalid checksum:              0
 Unknown/unsupported versions:  0
 Invalid vrID:                  10
 Too short:                     0
Protocol:
 Transitions to Master          6
Packets:
 Total received:                155
 Bad TTL:                       0
 Failed authentication:         0
 Unknown authentication:        0
 Conflicting authentication:    0
 Unknown Type field:            0
 Conflicting Advertise time:    0
 Conflicting Addresses:         0
 Received with zero priority:   3
 Sent with zero priority:       3
 

RP/0/RP0/CPU0:router# clear vrrp statistics
RP/0/RP0/CPU0:router

Additional References

The following sections provide references related to VRRP.

Related Documents

Related Topic

Document Title

QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

Quality of Service Commands on Modular QoS Command Reference for Cisco NCS 6000 Series Routers

Class-based traffic shaping, traffic policing, low-latency queuing, and Modified Deficit Round Robin (MDRR)

Configuring Modular Quality of Service Congestion Management on Modular QoSConfiguration Guide for Cisco NCS 6000 Series Routers

WRED, RED, and tail drop

Configuring Modular QoS Congestion Avoidance on Modular QoSConfiguration Guide for Cisco NCS 6000 Series Routers

VRRP commands

VRRP Commands on IP Addresses and Services Command Reference for Cisco NCS 6000 Series Routers

Information about user groups and task IDs

Configuring AAA Services on System Security Configuration Guide for Cisco NCS 6000 Series Routers

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