TCL error for basic port translation iRule

Background: I've set up a simple iRule that translates the requested VIP:PORT to NODE:PORT. Although, this iRule works well, I continue getting these TCL errors. I have tried using IF statements but this has ended up breaking my iRule. Does anyone know what would be causing this error? Thanks

LTM Version: BIG-IP 11.2.0 Build 2557.0 Hotfix HF2

Log > Local Traffic

err

TCL error: /Common/port_translation - bad IP address format (line 3) invoked from within "node $node_address_port"

Data Group List

Name: port_translation

Type: String

Example: 12080 := 10.0.0.120:8080

iRule

when HTTP_REQUEST {

set node_address_port [class match -value [TCP::local_port] equals /Common/port_translation]

log local0.info "Node address/port is $node_address_port"

node $node_address_port

}