i have pool with 2 memebrs , priority group activation is enabled one server is master & one is backup if master went down , monitor marks it down & traffic is sent to the other backup server The idea is that i want when master server is back , all coming connections needs to be sent to master ( even if it was sent to backup ) . This is UDP traffic

so when master is back , i don't want any connections ( new or old ) to be sent to backup

If you create two separate pools and place one member in each, this will work just fine providing you assign the 'main' pool as the default pool for the VS and disable the slow ramp time and priority group activation for each pool; when CLIENT_DATA { if { [active_members main_pool] != 0 } { pool main_pool } else { pool backup_pool } }

have you tried Datagram LB? sol3605: Configuring the BIG-IP system to load balance UDP packets individually http://support.f5.com/kb/en-us/solutions/public/3000/600/sol3605.html

Hi Steve , shall i sue CLIENT_DATA or CLIENT_ACCEPTED or LB_SELECTED ? it is UDP traffic Hi nitass , do you mean that LB Datagram option will instruct F5 not create connection table for UDP ?

If Datagram LB doesn't do it for you and you use the iRule it'll need to be CLIENT_DATA as CLIENT_ACCEPTED is only triggered once for the 'lifetime' of a UDP connection, which could be quite long if the UDP profile idle-time doesn't expire.