Jerexyz

  1. ping

    # ping a host with a total count of 15 packets overall.    
ping -c 15 www.example.com

# ping a host with a total count of 15 packets overall, one every .5 seconds (faster ping). 
ping -c 15 -i .5 www.example.com

# test if a packet size of 1500 bytes is supported (to check the MTU for example)
ping -s 1500 -c 10 -M do www.example.com

  2. fping

    A more powerful ping which can ping multiple hosts.

    # List alive hosts within a subnet generated from a netmask:
fping -a -g 192.168.1.0/24

# List alive hosts within a subnet generated from an IP range:
fping -a -g 192.168.1.1 192.168.1.254

# List unreachable hosts within a subnet generated from a netmask:
fping -u -g 192.168.1.0/24

  3. telnet

    # Connect to a specified port of a host using the telnet protocol.

# Telnet to the default port of a host:
  telnet host

# Telnet to a specific port of a host:
  telnet ip_address port

# Exit a telnet session:
  quit

# Emit the default escape character combination for terminating the session:
  Ctrl + ]

# Start telnet with "x" as the session termination character:
  telnet -e x ip_address port
    • exit telnet

    Escape character is '^]'. Since ^X is CtrlX, try Ctrl] for ^].