NMAP is also used for this scan and a level 3 scan is the first part of the scan. Level 4 scans then do a port scan. ... Level 4 Scan. Scan PhaseBytesTotal MB (ARP response)125 * 28 = 3500 bytes0.004 MB (Port scan)125 * 250000 = 31250000 bytes31 MB (DNS Lookup)125 * 512 = 64 kB0.064 MB 3 more rows Sep 8, 2020