Hosts Files

Host file: A simple text file that consists of one or more lines, each of which contains a hostname and an IP address

• The original way that numbered network addresses ​were correlated with words was through host files
•  ​For example, a line in a host file might ​read 1.2.3.4 web server.
  • ​This means that on ​the computer where this host file resides, ​a user could just refer to web server ​instead of the IP 1.2.3.4. ​Hosts files are evaluated by ​the networking stack of the operating system itself.
• host files are a popular way for ​computer viruses to disrupt and redirect users traffic

Loopback address: An IP address that always points to itself.

• This type of address is used to test internal pathing through the TCP/IP protocols
• The loopback IP for IPV4 is 127.0.0.1
  • It’s still to this day configured on ​every modern operating system ​through an entry in a host’s file. ​Almost every hosts file in ​existence will in the very least contain ​a line that reads 127.0.0.1 local host, ​most likely followed by::1, local host, ​where::1 is the loopback address for IPV6.