LB::detach command

Hello,

I wrote following iRule to loadbalance DNS requests.

rule DNS_LB {
  when RULE_INIT {
    ::zcn_bits 0x78
    ::zcn_sign 0x20
  }
  when CLIENT_DATA {
    if { [UDP::payload length] > 3 } {
      binary scan [UDP::payload] x2c1 dns_req_byte
      if { [expr $dns_req_byte & $::zcn_bits] == $::zcn_sign } {
        LB::detach
        pool DNS_UDP_dnsi01
      }
      else {
        LB::detach
        pool DNS_UDP_Not_Notify
      }
    }
  }
}

Then I sent DNS requests to VIP which assigned above iRule

from same client IP address and port No. in shortly time

(this means all datagramwas processed in same connection).

However, the BIG-IP output following error log.

TCL error: Rule DNS_LB - Address in use (line 4)

invoked from within "pool DNS_UDP_dnsi01"

It seems that the BIG-IP didn't detach server side connection

on "LB::detach" command.

Can I use "LB::detach" command for UDP connection?

Regards.