Forum Discussion

Nimbostratus

Aug 27, 2018

iRule for reset TCP connection if pool down

Hello, I have a kind of health monitor for my DNS (tcp half open) which check every 30sec the VS on my F5 LTM.

I would like the LTM reset connection when the VS is down. I tried this irule, my flow is deny by BIG IP even if I have my VS up.

when FLOW_INIT {
   if { [active_members [LB::server pool]] == 0 } {
      reject
   }

Thanks for your help!

Tyler_Shaw_9498
Historic F5 Account
Aug 27, 2018
You don't need to run an iRule when all pool members down. Set the "Action On Service Down feature" within the virtual server to "reject": https://support.f5.com/csp/article/K15095.
Jason_Reed
Ret. Employee
Jan 12, 2019
The irule doesn't work because you can not use a LB: (loadbalance) when FLOW_INIT - there hasn't been a LB decision yet.

use something like: when FLOW_INIT { if { [active_members http-pool] == 0 } { reset } }