Default Nmap Settings The following table describes the default Nmap settings used by the discovery scan: Option Description -sS Sets the TCP SYN Scan option. -T Sets the timing template. The higher the number, the faster the scan. By default, the discovery scan uses -T5. -PP, -PE, -PM Sets the echo, timestamp, and address mask reply probes. -PI Sets the ICMP ping sweep option. -PA Enables the TCP ACK ping. This type of ping sets the TCP ACK flag instead of the SYN flag.