Information Technology Reference
In-Depth Information
Intranet
An intranet is also generally a TCP/IP-based network, but it does not nec-
essarily include publically routed network addressing. Private addressing,
such as the 10.0.0.0/8 subnet originally reserved for BITNET, is often
used internally to provide cost savings on lease of public address space. An
intranet's purpose is to support an organization and its operations. Local
DNS may be used to give internal addressing user-friendly names, includ-
ing nonroutable naming using additional roots not part of the ICANN-
moderated public namespace (such as the common .local root).
Internal file storage, collaboration solutions, and other forms of inter-
connectivity have a place within an organization's intranet. Intranet
defenses typically involve gateway security and internal authentication
mechanisms for access control. Formal change management procedures
should be put into place for control over intranet resources to ensure con-
tinued function in the face of updates and network evolution.
Extranet
Similar to an intranet, the extranet is a privately accessible set of network
resources available for organizational operation. Extranets extend the
same functions as intranets but include external partners, suppliers, cus-
tomers, and other authenticated computing resources outside the organi-
zation's internal network space. Because of the rapid emergence of mobile
devices used for business purposes, the line between intranet and extranet
is increasingly blurred. Extranet security may involve stronger authenti-
cation mechanisms, such as two-factor log-ons, together with transport
encryption strategies to secure data traveling over public network seg-
ments. As with intranets, formal change management procedures are
mandatory for continued extranet function in the mid- to long term.
Summary
This chapter has focused on the evolution of Internet connectivity, from
the earliest days of the ARPANet through Web 1.0, 2.0, and beyond.
Enterprises must consider the global nature of the Internet when secur-
ing online naming and when competing for attention in the worldwide
on l i ne ma rket plac e. A s enter prise net work s bec ome i ncre a si ng ly e x tended,
challenges will arise for control and management of content and name
