Case Study: Network Address Translation

Network Address Translation (NAT) allows a network administrator to translate one set of IP addresses into another—for example, allowing a host with a private address to appear on the Internet with a registered address. NAT can also be used to load balance between servers, provide server redundancy, and connect companies that use the same address space.

The host in Figure 2-16,, wants to reach, which is a server on the Internet. However, its address,, is a private address and cannot be routed on the Internet. To resolve this addressing problem, Router A can translate the packets sourced from so they appear to be sourced from a registered Internet address, ...

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