The post 5 Ways to Test TCP and UDP Ports in Linux Using nc, nmap, ss, and Bash first appeared on Tecmint: Linux Howtos, Tutorials & Guides .Telnet is missing from almost every modern Linux install, but you can still test TCP or UDP ports with nc,The post 5 Ways to Test TCP and UDP Ports in Linux Using nc, nmap, ss, and Bash first appeared on Tecmint: Linux Howtos, Tutorials & Guides.