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Hello Experts,<br />
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Can anyone explain why Zone Based Firewalls would inspect layer 7 protocols for common protocols such as http, smtp, pop3, imap, etc...<br />
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I'm reading about ZBFs and do not understand why a layer 7 deep inspection would be necessary when the firewall is already inpecting on 3/4 layer. Can anyone help me understand why?
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Hello Experts,

Can anyone explain why Zone Based Firewalls would inspect layer 7 protocols for common protocols such as http, smtp, pop3, imap, etc...

I'm reading about ZBFs and do not understand why a layer 7 deep inspection would be necessary when the firewall is already inpecting on 3/4 layer. Can anyone help me understand why?

ZBF question on Cisco 1841

Cisco PIX is a dedicated hardware firewall appliance; the Cisco Adaptive Security Appliance (ASA) is a firewall and anti-malware security appliance that provides unified threat management and protection the PIX does not. Other Cisco devices and systems include routers, switches, storage networking, wireless and the software and hardware for PIX Firewall Manager (PFM), PIX Device Manager (PDM) and Adaptive Security Device Manager (ASDM).

Cisco

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.