How to mapping client with Server using iRUle

Hi Voung Hong Vu,

i would create to independent pools for the two backend systems with priority based activation where each pool is prefering a different app server.

App_Pool1
    Node1: 172.16.36.49 Priority 1
    Node2: 172.16.36.50 Priority 0
App_Pool2
    Node1: 172.16.36.49 Priority 0
    Node2: 172.16.36.50 Priority 1 

For further information on priority based activation see: https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm_configuration_guide_10_0_0/ltm_pools.html1216212

Once done, then configure the iRule below on the virtual server serving your app servers.

when CLIENT_ACCEPTED {
    if { [IP::client_addr] equals 172.16.41.55 } then {
        pool App_Pool1
    } else {
        pool App_Pool2
    }
}

Note: Change

[IP::client_addr] equals 172.16.41.55

[IP::client_addr] starts_with 172.16.41.55

Cheers, Kai