TMS zl Management and Configuration Guide ST.1.1.100226

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Firewall
General Firewall Concepts
Today’s networks have changed, however. As companies have adapted their
networks to meet the ever-changing face of business, the boundaries between
private and public networks have blurred. The Internet has become a critical
work tool for nearly every company, and companies have opened parts of their
private network to guests—such as partners and customers—allowing tem-
porary and permanent accounts with varying levels of access.
Although providing guests with limited network access is a good business
practice, it introduces security vulnerabilities into what was the inside, trusted
network. You must protect that network against these less-trusted users. And,
with a large percentage of attacks originating from internal sources, event
authorized users and employees might not be entirely trusted users.
In addition, even trusted users have different roles and should have rights to
different resources. Companies must implement security policies that regu-
late even internal users’ rights to internal resources.
Because these threats are occurring on the inside, trusted network, traditional
security measures—such as firewalls strategically placed between the private
and public networks—do not detect them. The traditional security measures
are still required, but companies must implement additional measures to
protect the network in this new environment. They must filter traffic within
the trusted network, checking for attacks and controlling access to network
resources.
The HP ProCurve Threat Management Services (TMS) zl Module provides this
kind of protection. The TMS zl Module acts as a traditional firewall between
and within networks. The module controls all network traffic, not just traffic
flowing between the trusted network and the untrusted; it allows you to filter
internal traffic, as well.
Advantages of an Integrated Firewall
Although firewall software can protect individual PCs, a firewall integrated
into a switch has several advantages:
■ Software firewalls often use mainstream operating systems. Attackers
study such systems for vulnerabilities. These operating systems are more
vulnerable to targeted attacks and sporadic lock-ups, which can take
down your firewall and leave your network unprotected.
■ A switch firewall protects your network entry points, stopping threats
before they get through the switch.
■ A firewall integrated with a switch allows your organization to enforce a
standard security policy for all hosts.