The firewall in a multilayer security approach
What a firewall can and can’t do
A firewall can be hardware- or software-based. The tightest security is obtained when the two options are used in combination. Yet, even in this approach, a firewall system has its limits:

It can’t protect the enterprise from attacks and threats from within your network.
Virus protection is limited without additional software and specialized technologies.
A firewall can’t protect an organization from attacks that avoid a firewall—an external hack via a dial-up account can fully compromise the entire security plan.

Firewall technology, obviously, also can’t protect organizations from employee carelessness or mistakes with passwords and unauthorized access. Only specific tools and policy guidelines on expected computer use and access can thwart those issues.

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