Zone Based Firewall
ZBF (Zone Based Firewall) is the stateful firewall that is available on Cisco IOS routers, introduced in 2006. ZBF supports deep packet inspection just like an ASA. ZBF works based on the concept of security zones. You can name the zones whatever you want. In ZBF we don’t assign access-list to the interface. We create zones and the interface will be configured to the different zones (one interface can only be a member of one zone) and security policies will be assigned. The default policy is to block all the traffic unless we explicitly allow it.
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