Strict active/standby interface backup configuration example

Network requirements

As shown in Figure 3:

Figure 3: Network diagram

Configuration procedure

  1. Assign IP addresses to interfaces, as shown in Figure 3. (Details not shown.)

  2. Configure routes:

    # On Router A, configure static routes to 192.168.2.0/24 through the primary and backup interfaces.

    <RouterA> system-view
    [RouterA] ip route-static 192.168.2.0 24 gigabitethernet 1/0/1 1.1.1.2
    [RouterA] ip route-static 192.168.2.0 24 gigabitethernet 1/0/2 2.2.2.2
    [RouterA] ip route-static 192.168.2.0 24 gigabitethernet 1/0/3 3.3.3.2
    

    # On Router B, configure static routes to 192.168.1.0/24.

    <RouterB> system-view
    [RouterB] ip route-static 192.168.1.0 24 gigabitethernet 1/0/1 1.1.1.1
    [RouterB] ip route-static 192.168.1.0 24 gigabitethernet 1/0/2 2.2.2.1
    [RouterB] ip route-static 192.168.1.0 24 gigabitethernet 1/0/3 3.3.3.1
    
  3. On Router A, configure backup interfaces and switchover delays:

    # Specify GigabitEthernet 1/0/2 and GigabitEthernet 1/0/3 to back up GigabitEthernet 1/0/1, and assign them a priority of 30 and 20, respectively.

    [RouterA] interface gigabitethernet 1/0/1
    [RouterA-GigabitEthernet1/0/1] backup interface gigabitethernet 1/0/2 30
    [RouterA-GigabitEthernet1/0/1] backup interface gigabitethernet 1/0/3 20
    

    # Set both up and down delay timers to 10 seconds.

    [RouterA-GigabitEthernet1/0/1] backup timer delay 10 10
    

Verifying the configuration

# Display states of the primary and backup interfaces.

[RouterA-GigabitEthernet1/0/1] display interface-backup state

Interface: GE1/0/1

  UpDelay: 10 s
  DownDelay: 10 s

State: UP

  Backup interfaces:

GE1/0/2 Priority: 30 State: STANDBY

GE1/0/3 Priority: 20 State: STANDBY

The output shows that GigabitEthernet 1/0/1 is in UP state and the two backup interfaces are in STANDBY state.

# Shut down the primary interface GigabitEthernet 1/0/1.

[RouterA-GigabitEthernet1/0/1] shutdown

# Verify that the backup interface GigabitEthernet 1/0/2 comes up 10 seconds after the primary interface goes down.

[RouterA-GigabitEthernet1/0/1] display interface-backup state

Interface: GE1/0/1

  UpDelay: 10 s
  DownDelay: 10 s

State: DOWN

  Backup interfaces:

GE1/0/2 Priority: 30 State: UP

GE1/0/3 Priority: 20 State: STANDBY