nmap -p- -Pn -n 172.28.128.3
-p-: you can specify
-p- to scan ports from 1 through 65535.
-Pn: Treat all hosts as online — skip host discovery
-n/-R: Never do DNS resolution/Always resolve [default: sometimes]
nmap -sV -T4 -p-65535 172.28.128.3
-sV option enables Nmap version detection, which is trained to look for these clues (among others).
-T4 prohibits the dynamic scan delay from exceeding 10 ms for TCP ports and
-T5 caps that value at 5 ms.
-p-65535: scan all ports to 65535
Reference to values for T: T Table