DNS notify loadbalancing

2 things

1) when dealing with TCP, in client_accepted, you may collect data first...do what you need in client_data, then release the data...

your irule may look like this...

when CLIENT_ACCEPTED {

TCP::collect

}

when CLIENT_DATA {

do what you what here...

TCP::release

}

2)

according to rfc 1035

4.2.2. TCP usage

Messages sent over TCP connections use server port 53 (decimal). The

message is prefixed with a two byte length field which gives the message

length, excluding the two byte length field. This length field allows

the low-level processing to assemble a complete message before beginning

to parse it.

so your binary scan command has to change to

binary scan [TCP::payload] SSS length id flags

combine both together it probably look like this... (not test)

when CLIENT_ACCEPTED {
        TCP::collect
}
when CLIENT_DATA {
        binary scan [TCP::payload] SSS length id flags   
        set opcode [expr ($flags >> 11) & 0xf]
         Send NOTIFYs (opcode 4) to the master SQL database node.
        if { $opcode == 4 } {
                log local0. "DEBUG: NOTIFY TCP, sending to MASTER"
                node  MASTER_SERVER_IP 53
        }
        else {
                log local0. "DEBUG TCP: NOT A NOTIFY"
        }
        TCP::release
}

Nat