A secure repeater implementing data packet masking includes a programmable and selective, on a per port basis, delay disrupt response. A delay disrupt controller receives signals indicating retransmissions of fields from a data packet. These signals include a destination address field and a source address field. A plurality of memories, one associated with each port, determines the associated port's delay response to the data packet. Each memory stores a delay disrupt control code. When the delay disrupt control code for a particular port has a value indicating that the associated port is enabled to delay disruption of a data packet, security marking is disabled until the source address field is retransmitted from the particular port.