about the HA feature of two F5 BIG-IP 1600 LTM load balancers

Dear all F5 experts,

 

I have two F5 BIG-IP 1600 LTM load balancers. One F5 BIG-IP 1600 is active status & another F5 BIG-IP 1600 is standby status.

 

Thus, I think all the network traffic to the virtual IP must pass through the active F5 BIG-IP 1600.

 

I guess the standby F5 BIG-IP 1600 just keep at standby mode and no network traffic pass through it.

 

However, on "Module Statistics of Network -> interface statistics" of standby F5 BIG-IP 1600, there are a lot of network traffic on the data interfaces of standby F5 BIG-IP 1600.

 

May you please give some advice on the questions below ?

 

Is the standby F5 BIG-IP also work at the same time as active F5 BIG-IP is working ?

 

OR Is all the network traffic must pass the active F5 BIG-IP 1600 firstly unless active F5 BIG-IP 1600 is down ?

 

Thanks very much,

 

Roc