Cisco Catalyst 2000 Configuration Handbook page 40

Building A
Si
Si Si
Server
Block
Figure 2-2 Modular Approach to a Campus Network Design Consider High Availability or
Redundancy Features That Can Be Used in Each Network Building Block
Tip The network in Figure 2-2 is shown with single uplinks to higher layers for simplicity.
In a real network, you need to always add dual redundant uplinks to two switches in the
next higher network layer for the highest network availability.
In this case, each access layer switch would have two uplinks to the two nearest distribution
switches. In addition, each distribution switch in each block of the diagram would have two
uplinks to the two core layer switches. In other words, the basic principles of Figure 2-1
need to be applied to the enterprise layout of Figure 2-2.
■ Server farms and mainframes: These are called server blocks and mainframe
blocks, respectively.
Internet access, e-commerce or extranet server farms, and firewall farms:
■
These are called an Internet block.
Switch
Blocks
Building Z
...
Si Si
Si
Si
Mainframe
Block
Chapter 2: Switch Functionality 19
Si
Core
Block
Si
Si
Si
V V
V V
PSTN
Block
WAN
Block
Si
Internet
Block