Page 195 - CISSO_Prep_ Guide

Of course, a firewall is only as good as the person that manages
it, so an important role of the security manager is to verify that
the staff managing the firewalls and other network devices are
knowledgeable, trained, and supervised. Firewall logs must be
reviewed regularly to detect any suspicious activity.

Proxy
A proxy is a device that acts as an intermediary between two
communicating parties. The proxy acts to the party on each side
of the communication as if it was the other end host. This allows
it to filter and examine suspicions activity, protect internal
resources, and take action if an unacceptable activity is
occurring. A gateway is often a type of proxy that controls
traffic through a gate or security perimeter.

DNS

For most people, the DNS (domain name system) is the
mechanism that makes the internetwork. Without the DNS, they
could not navigate to their destination website without knowing
the IP (internet protocol) address of the website they wanted to
visit. The DNS provides a simple cross-reference that is used to
associate a “normal” name with the IP address used by network
devices. The IP address is a logical address given to a website
based on the addresses allocated to the ISP (Internet Service
Provider). Individuals can purchase a name for their website that
is more in line with their name, the name of their organization,
or their marketing program. The IP address for Mile2.com, for
example, is 206.214.216.216. A person wanting to visit the
Mile2 website could simply type in http://206.214.216.216/.
That is the “real” address of the website. However, it is much