the.com/firewalls
a bouncer for your data, checking IDs at every door packets try to enter.
means a firewall is a system that monitors and filters network traffic based on rules, blocking what it decides is unsafe or unwanted.
from named after the literal construction firewall that stops fire spreading between building sections; 1980s network engineers borrowed the metaphor when routers started blocking bad traffic between networks.
first firewallpacket filters built by digital equipment corp, 1988
stateful upgrade1990s firewalls learned to track connections, not just packets
biggest mytha firewall alone stops nothing malware already inside
modern formoften just software rules inside your cloud provider
for instance
great firewall of china — blocks google, facebook, and thousands of sites since 2003
pfsense — open source firewall running on millions of home and business routers
cisco asa — corporate firewall hardware deployed across banks worldwide since 2005
windows defender firewall — built into every windows pc since xp sp2, 2004