data group iRule

Hi you don't need to use static variables - just use a TCP connection scoped variable set in CLIENT_ACCEPTED. Not too sure what you want from the switch ...anyway updated slightly

when CLIENT_ACCEPTED {
    set ecmvpn_flag 0
    if { [class match [IP::client_addr] equals ecmvpn_ip_dg] } {
        set ecmvpn_flag 1
    }
}

when HTTP_REQUEST {
    if {$ecmvpn_flag}{
         You need an FQDN here so I've added ".com.au"
        HTTP::redirect http://ecmvpn.com.au[HTTP::uri]
        return
    }

    switch -glob [string tolower [HTTP::host]] {
        "ecm.*"
            {
                if {[string tolower [HTTP::uri]] starts_with "/application"} {   
                        HTTP::header insert USER-IP  [IP::remote_addr]
                         You could just use an HTTP persistence profile attached to the virtual for this
                        persist cookie insert
                        pool pl_DCTM_ECM_APPLICATION 
                        return
            }
        }
        default { return }
    }

}