CLI Reference  REUP Configuration Commands 
switchport backup interface interface-id preemption 
Use this command to configure the REUP link preemption function. 
switchport  backup  interface  interface-id  preemption  mode  {forced  |  bandwidth  |  off  } 
switchport  backup  interface  interface-id  preemption  delay  delay-time 
no  switchport  backup  interface  interface-id  preemption  delay 
The interface id of the backup link. 
The preemption delay time. 
The preemption function is disabled by default.   
The default preemption delay time is 35s.     
Interface configuration mode. 
The preemption mode includes forced, bandwidth and off. In the 
bandwidth preemption mode, the interface with high bandwidth has 
priority over other interfaces to transmit the data. In the forced 
preemption mode, the primary has priority over backup interfaces to 
transmit the data. No preemption event occurrs in the off preemption 
mode. By default, the preemption mode is off.   
The preemption delay refers to the delay time of the link reswitch after 
the restoration of the link failure. 
The following example shows how to set the dual link backup, with fa 
0/1 and fa 0/2 as the primary interface and backup interface, set the 
bandwidth preemption mode and 40s preemption delay: 
Ruijie(config)# interface fa 0/1 
Ruijie(config-if)# switchport backup interface fa 0/2 
preemption mode bandwitdh 
Ruijie(config-if)# switchport backup interface fa 0/2 
preemption delay 40 
show  interface 
switchport 
backup 
View the dual link backup configuration.