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Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
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Chapter 1 Overview
Network Configuration Examples
Figure 1-2
Expanded Data Center
Small to Medium-Sized Network
Figure 1-3
shows a configuration for a network of up to 500 employees. This network uses a Layer 3
switch stack with high-speed connections to two routers. For network reliability and load-balancing, this
network has HSRP enabled on the routers and on the switches. This ensures connectivity to the Internet,
WAN, and mission-critical network resources in case one of the routers or switches fails. The switches
are using routed uplinks for faster failover. They are also configured with equal-cost routing for load
sharing and redundancy. A Layer 2 switch stack can use cross-stack EtherChannel for load sharing.
The switches are connected to local servers. The server farm includes a call-processing server running
Cisco CallManager software. Cisco CallManager controls call processing and routing. The switches are
interconnected through Gigabit interfaces.
This network uses VLANs to logically segment the network into well-defined broadcast groups and for
security management. Data and multimedia traffic are configured on the same VLAN. Voice traffic is
configured on separate VVIDs. If data, multimedia, and voice traffic are assigned to the same VLAN,
only one VLAN can be configured per wiring closet.
When an end station in one VLAN needs to communicate with an end station in another VLAN, a router
or Layer 3 switch routes the traffic to the destination VLAN. In this network, the switch stack is
providing inter-VLAN routing. VLAN access control lists (VLAN maps) on the switch stack or switch
provide intra-VLAN security and prevent unauthorized users from accessing critical areas of the
network.
In addition to inter-VLAN routing, the multilayer switches provide QoS mechanisms such as DSCP
priorities to prioritize the different types of network traffic and to deliver high-priority traffic. If
congestion occurs, QoS drops low-priority traffic to allow delivery of high-priority traffic.
Cisco CallManager controls call processing and routing. Users with workstations running Cisco
SoftPhone software can place, receive, and control calls from their PCs. Using Cisco CallManager
software and Cisco SoftPhone software integrates telephony and IP networks, and the IP network
supports both voice and data.
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Campus
core
Catalyst
6500 switches
Catalyst 6500
multilayer switches
Blade switch
StackWise
switch stacks
Blade server
enclosures