Example: Configuring BFD for the VRRP master to monitor the uplinks

As shown in Figure 60:

• Switch A and Switch B belong to VRRP group 1. The virtual IP address of VRRP group 1 is 192.168.0.10.

• The default gateway of the hosts in the LAN is 192.168.0.10.

Configure VRRP-Track-BFD collaboration to monitor the uplink on the master and meet the following requirements:

• When Switch A operates correctly, the hosts in the LAN access the Internet through Switch A.

• When Switch A detects that the uplink is down through BFD, Switch B can preempt as the master. The hosts in the LAN can access the Internet through Switch B.

	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. Create VLANs and assign ports to them. Configure the IP address of each VLAN interface, as shown in Figure 60. (Details not shown.)

2. Configure Switch A:

   # Specify 10.10.10.10 as the source address of BFD echo packets.

   <SwitchA> system-view
   [SwitchA] bfd echo-source-ip 10.10.10.10
   

   # Create track entry 1 for the BFD session to verify the reachability of the uplink device (1.1.1.2 ).

   [SwitchA] track 1 bfd echo interface vlan-interface 3 remote ip 1.1.1.2 local ip 1.1.1.1
   

   # Create VRRP group 1, and specify 192.168.0.10 as the virtual IP address of the group.

   [SwitchA] interface vlan-interface 2
   [SwitchA-Vlan-interface2] vrrp vrid 1 virtual-ip 192.168.0.10
   

   # Set the priority of Switch A to 110 in VRRP group 1.

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

   # Associate VRRP group 1 with track entry 1 and decrease the router priority by 20 when the state of track entry 1 changes to negative.

   [SwitchA-Vlan-interface2] vrrp vrid 1 track 1 priority reduced 20
   [SwitchA-Vlan-interface2] return
   

3. On Switch B, create VRRP group 1, and specify 192.168.0.10 as the virtual IP address of the group.

   <SwitchB> system-view
   [SwitchB] interface vlan-interface 2
   [SwitchB-Vlan-interface2] vrrp vrid 1 virtual-ip 192.168.0.10
   [SwitchB-Vlan-interface2] return
   

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

<SwitchA> 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   : 0
     Auth Type        : None
     Virtual IP       : 192.168.0.10
     Virtual MAC      : 0000-5e00-0101
     Master IP        : 192.168.0.101
   VRRP Track Information:
     Track Object   : 1              State : Positive          Pri Reduced : 20

# Display information about track entry 1 on Switch A.

<SwitchA> display track 1
Track ID: 1
  State: Positive
  Duration: 0 days 0 hours 0 minutes 32 seconds
  Notification delay: Positive 0, Negative 0 (in seconds)
  Tracked object:
    BFD session mode: Echo
    Outgoing interface: Vlan-interface2
    VPN instance name: --
    Remote IP: 1.1.1.2
    Local IP: 1.1.1.1

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

<SwitchB> 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   : 0
     Become Master    : 2200ms left
     Auth Type        : None
     Virtual IP       : 192.168.0.10
     Master IP        : 192.168.0.101

The output shows that when the status of track entry 1 becomes Positive, Switch A is the master and Switch B is the backup.

# Display information about track entry 1 when the uplink of Switch A goes down.

<SwitchA> display track 1
Track ID: 1
  State: Negative
  Duration: 0 days 0 hours 0 minutes 32 seconds
  Notification delay: Positive 0, Negative 0 (in seconds)
  Tracked object:
    BFD session mode: Echo
    Outgoing interface: Vlan-interface2
    VPN instance name: --
    Remote IP: 1.1.1.2
    Local IP: 1.1.1.1

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

<SwitchA> 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       : 110             Running Pri  : 90
     Preempt Mode     : Yes             Delay Time   : 0
     Become Master    : 2200ms left
     Auth Type        : None
     Virtual IP       : 192.168.0.10
     Master IP        : 192.168.0.102
   VRRP Track Information:
     Track Object   : 1              State : Negative          Pri Reduced : 20

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

<SwitchB> 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   : 0
     Auth Type        : None
     Virtual IP       : 192.168.0.10
     Virtual MAC      : 0000-5e00-0101
     Master IP        : 192.168.0.102

The output shows that when Switch A detects that the uplink fails through BFD, it decreases its priority by 20. Switch B then preempts as the master.