F5 force connection reset on pool member

Hi Satish,

you may take a look to the iRule below.

The iRule deploys a periodic

[after]

taskjob within each TCP connection, which compares every few seconds your selected pool member with the currently prefered pool member (influenced by its health, forced offline status and priority group settings) and reject the ongoing TCP connection if those are not matching anymore.

Cleaned iRule

when RULE_INIT {
    set static::connection_check_interval 5000 ; msec
}
when LB_SELECTED {
    after $static::connection_check_interval -periodic {
        if { [lindex [LB::select] 3] ne [LB::server addr] } then {
            reject          
        }
    }
}

Debug enabled iRule

when RULE_INIT {
    set static::connection_check_interval 5000 ; msec
}
when LB_SELECTED {
    set connection_timestamp "[TMM::cmp_group][TMM::cmp_unit][clock clicks]"
    log local0.debug "Node UP Check: $connection_timestamp : The pool member [LB::server addr] is currently active. Scheduling initial status check in $static::connection_health_interval ms."
    after $static::connection_check_interval -periodic {
        log local0.debug "Node UP Check: $connection_timestamp : Performing status check for pool member [LB::server addr]"
        if { [lindex [LB::select] 3] ne [LB::server addr] } then {
            log local0.debug "Node UP Check: $connection_timestamp : [LB::server addr] is not the active member anymore. Rejecting the TCP connection."
            reject
        } else {
            log local0.debug "Node UP Check: $connection_timestamp : [LB::server addr] is still the active member. Scheduling next status check in $static::connection_health_interval ms."
        }
    }
}

Cheers, Kai