No more pizza boxes: Traditional hardware firewalls can’t adequately protect a modern corporate network and its users. Why? Because while there still may be physical servers inside an on-premises data center or in a wiring closet somewhere, an increasing number of essential resources are virtualized or off-site. And off-site includes servers in infrastructure-as-a-service (IaaS) and platform-as-a-service (PasS) clouds.
It’s the enterprise’s responsibility to protect each of those assets, as well as the communications paths to and from those assets, as well as public Internet connections. So, no, a pizza-box appliance next to the router can’t protect virtual servers, IaaS or PaaS. What’s needed are the poorly named “next-generation firewalls” (NGFW) — very badly named because that term is not at all descriptive, and will seem really stupid in a few years, when the software-based NGFW will magically become an OPGFW (obsolete previous-generation firewall).
Still, the industry loves the “next generation” phrase, so let’s stick with NGFW here. If you have a range of assets that must be protected, including some combination of on-premises servers, virtual servers and cloud servers, you need an NGFW to unify protection and ensure consistent coverage and policy compliance across all those assets.
Cobbling together a variety of different technologies may not suffice, and could end up with coverage gaps. Also, only an NGFW can detect attacks or threats against multiple assets; discrete protection for, say, on-premises servers and cloud servers won’t be able to correlate incidents and raise the alarm when an attack is detected.
Next-generation firewalls (NGFWs) are deep-packet inspection firewalls that move beyond port/protocol inspection and blocking to add application-level inspection, intrusion prevention, and bringing intelligence from outside the firewall.
What this means is that an NGFW does an excellent job of detecting when traffic is benign or malicious, and can be configured to analyze traffic and detect anomalies in a variety of situations. A true NGFW looks at northbound/southbound traffic, that is, data entering and leaving the network. It also doesn’t trust anything: The firewall software also examines eastbound/westbound traffic, that is, packets flowing from one asset inside the network to another.
After all, an intrusion might compromise one asset, and use that as an entry point to compromise other assets, install malware, exfiltrate data, or cause other mischief. Where does the cloud come in? Read my essay for SecurityNow, “Next-Generation Firewalls: Poorly Named but Essential to the Enterprise Network