Nmap is a very useful and effective port-scanner / network enumeration tool. Here are some fun things you can do with it:
Do not forget to use the following flag when stealth is important.
--script-args http.useragent="CUSTOM_AGENT"
nmap -sn <ip>/<cidr>
nmap -p<port> -A <ip>
nmap -p- -sS <ip>
nmap -p- -v -T4 <ip>
nmap -p<ports> -sV -sC -T4 -Pn -oA <ip> <ip>
Threader3000 has quickly became my go to port scanning tool. It can be used to quickly scan all ports on a host, then perform a verbose Nmap scan on only the discovered ports. The speed and thoroughness of this tool just cant be beat
pip install threader3000
threader3000
nmap -p445 --script=smb-enum-shares.nse,smb-enum-users.nse <ip>
nmap -p 111 --script=nds-la,nfs-statfs,nfs-showmount <ip>