CEIT

The Internet

Useful commands (Linux):

  1. ping (e.g.: ping www.google.com) - Check if www.google.com can be contacted.
  2. dig (e.g.: dig www.google.com) - Gives the IP address(es) of www.google.com
  3. ip a - Shows the network adaptors and details including IP addresses.
  4. ip r - Shows the routing table

Useful commands (Windows):

  1. ping (e.g.: ping www.google.com) - Check if www.google.com can be contacted.
  2. nslookup (e.g.: nslookup www.google.com) - Gives the IP address(es) of www.google.com
  3. ipconfig - Shows the IP address of the computer, subnet mask and default gateway.
  4. Question: What command can be used to view the routing table?

Software

  1. Download Putty
    Download the MSI (‘Windows Installer’) for your architecture (typically 64-bit x86)

How to make an HTTP request using a telnet client (like Putty)?

Linux (using 'telnet' tool):

$ telnet www.google.com 80
Trying 2404:6800:4003:c01::68...
Connected to www.google.com.
Escape character is '^]'.
GET / HTTP/1.0

HTTP/1.0 200 OK
Date: Thu, 05 Feb 2026 10:09:07 GM
...

Windows (using Putty):

  1. Start Putty application.
  2. Specify the host name (like www.google.com).
  3. Specify port number 80.
  4. Specify connection type 'Raw'.
  5. Connect.
  6. Type "GET / HTTP/1.0" and hit Enter key.
  7. Hit Enter key again.
  8. You should now see the output from the server.