Example: Configuring a single VRRP group

As shown in Figure 51, Switch A and Switch B form a VRRP group. They use the virtual IP address 10.1.1.111/24 to provide gateway service for the subnet where Host A resides.

Switch A operates as the master to forward packets from Host A to Host B. When Switch A fails, Switch B takes over to forward packets for Host A.

	IMPORTANT: By default, interfaces on the device are disabled (in ADM or Administratively Down state). To have an interface operate, you must use the undo shutdown command to enable that interface.

1. Configure Switch A:

   # Configure VLAN 2.

   <SwitchA> system-view
   [SwitchA] vlan 2
   [SwitchA-vlan2] port fortygige 1/0/5
   [SwitchA-vlan2] quit
   [SwitchA] interface vlan-interface 2
   [SwitchA-Vlan-interface2] ip address 10.1.1.1 255.255.255.0
   

   # Create VRRP group 1 on VLAN-interface 2, and set its virtual IP address to 10.1.1.111.

   [SwitchA-Vlan-interface2] vrrp vrid 1 virtual-ip 10.1.1.111
   

   # Assign Switch A a higher priority than Switch B in VRRP group 1, so Switch A can become the master.

   [SwitchA-Vlan-interface2] vrrp vrid 1 priority 110
   

   # Configure Switch A to operate in preemptive mode, so it can become the master whenever it operates correctly. Set the preemption delay to 5000 centiseconds to avoid frequent status switchover.

   [SwitchA-Vlan-interface2] vrrp vrid 1 preempt-mode delay 5000
   

2. Configure Switch B:

   # Configure VLAN 2.

   <SwitchB> system-view
   [SwitchB] vlan 2
   [SwitchB-Vlan2] port fortygige 1/0/5
   [SwitchB-vlan2] quit
   [SwitchB] interface vlan-interface 2
   [SwitchB-Vlan-interface2] ip address 10.1.1.2 255.255.255.0
   

   # Create VRRP group 1 on VLAN-interface 2, and set its virtual IP address to 10.1.1.111.

   [SwitchB-Vlan-interface2] vrrp vrid 1 virtual-ip 10.1.1.111
   

   # Set the priority of Router B to 100 in VRRP group 1.

   [SwitchB-Vlan-interface2] vrrp vrid 1 priority 100
   

   # Configure Switch B to operate in preemptive mode, and set the preemption delay to 5000 centiseconds.

   [SwitchB-Vlan-interface2] vrrp vrid 1 preempt-mode delay 5000
   

# Ping Host B from Host A. (Details not shown.)

# Display detailed information about VRRP group 1 on Switch A.

[SwitchA-Vlan-interface2] display vrrp verbose
IPv4 Virtual Router Information:
 Running Mode      : Standard
 Total number of virtual routers : 1
   Interface Vlan-interface2
     VRID             : 1                    Adver Timer  : 100
     Admin Status     : Up                   State        : Master
     Config Pri       : 110                  Running Pri  : 110
     Preempt Mode     : Yes                  Delay Time   : 5000
     Auth Type        : None
     Virtual IP       : 10.1.1.111
     Virtual MAC      : 0000-5e00-0101
     Master IP        : 10.1.1.1

# Display detailed information about VRRP group 1 on Switch B.

[SwitchB-Vlan-interface2] display vrrp verbose
IPv4 Virtual Router Information:
 Running Mode      : Standard
 Total number of virtual routers : 1
   Interface Vlan-interface2
     VRID             : 1                    Adver Timer  : 100
     Admin Status     : Up                   State        : Backup
     Config Pri       : 100                  Running Pri  : 100
     Preempt Mode     : Yes                  Delay Time   : 5000
     Become Master    : 401ms left
     Auth Type        : None
     Virtual IP       : 10.1.1.111
     Master IP        : 10.1.1.1

The output shows that Switch A is operating as the master in VRRP group 1 to forward packets from Host A to Host B.

# Disconnect the link between Host A and Switch A, and verify that Host A can still ping Host B. (Details not shown.)

# Display detailed information about VRRP group 1 on Switch B.

[SwitchB-Vlan-interface2] display vrrp verbose
IPv4 Virtual Router Information:
 Running Mode      : Standard
 Total number of virtual routers : 1
   Interface Vlan-interface2
     VRID             : 1                    Adver Timer  : 100
     Admin Status     : Up                   State        : Master
     Config Pri       : 100                  Running Pri  : 100
     Preempt Mode     : Yes                  Delay Time   : 5000
     Auth Type        : None
     Virtual IP       : 10.1.1.111
     Virtual MAC      : 0000-5e00-0101
     Master IP        : 10.1.1.2

The output shows that when Switch A fails, Switch B takes over to forward packets from Host A to Host B.

# Recover the link between Host A and Switch A, and display detailed information about VRRP group 1 on Switch A.

[SwitchA-Vlan-interface2] display vrrp verbose
IPv4 Virtual Router Information:
 Running Mode      : Standard
 Total number of virtual routers : 1
   Interface Vlan-interface2
     VRID             : 1                    Adver Timer  : 100
     Admin Status     : Up                   State        : Master
     Config Pri       : 110                  Running Pri  : 110
     Preempt Mode     : Yes                  Delay Time   : 5000
     Auth Type        : None
     Virtual IP       : 10.1.1.111
     Virtual MAC      : 0000-5e00-0101
     Master IP        : 10.1.1.1

The output shows that after Switch A resumes normal operation, it becomes the master to forward packets from Host A to Host B.