old notes

#nmap #netstat #netcat #ncat #telnet #tcpdump #curl #wireshark #bannercapture

nmap: networking mapper/port scanner that reports what it is able to connect to

USAGE:
– when you want to know about open ports on a remote system
– when you want further info about the service listening on each port
– when you need a second opinion about listening ports

netstat: network statistics / diagnostic that reports what the kernel knows about listening the established connections

USAGE:
– what is listening on your local machine?
– process or interface/address info for each port
– ONLY IF you trust the OS to give the correct answer (if you've been hacked, a rootkit can make the OS lie to netstat about what really is going on)

netcat: port-scanning, banner grabbing, transfer files

• open ports, send packets, receive packets
• file transfer, sending custom requests to services (SMTP, HTTP), tunneling
• handles lower OSI layers of connection so user can manipulate upper layers as needed; banners are at application layer

ncat: concatenate and redirect sockets

telnet

tcpdump

wireshark

Follow-Up Questions

• why are banners are application level
• nc vs nmap usage cases for banner capture