Information Technology Reference
In-Depth Information
Device Contexts
Device contexts enable a single physical network device to host multiple virtual network
devices. Each device context is an independent configuration with its own policy, network
interfaces, and management accounts. The virtualized contexts that run on a single net-
work device operate similarly to standalone network devices. Most of the same features
present on the physical device are also supported on the individual device contexts.
Key
To p i c
The following Cisco network devices support the use of device contexts:
Cisco Nexus 7000 series switches (VDC)
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Cisco Adaptive Security Appliance (ASA) firewall
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Cisco Catalyst 6500 Firewall Services Module (FWSM)
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Cisco Application Control Engine Appliance
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Cisco Catalyst 6500 Application Control Engine Module
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Cisco Intrusion Prevention System (IPS)
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Server Virtualization
The use of server virtualization has exploded onto the market over the past several years
and can be found in most data center environments. Server virtualization is a software
technique that abstracts server resources form the hardware to provide flexibility and to
optimize the usage of the underlying hardware. As a result, many data center applications
are no longer bound to bare-metal hardware resources.
The server virtualized hypervisor provides the foundation for the virtualized environment
on the host. The hypervisor controls the hardware and physical resources that can be allo-
cated to virtual machines running on the host. This makes the VMs unaware of the physi-
cal hardware, but they can use CPUs, memory, and network infrastructure as shared pools
available through the virtualization process.
The follow ing represents several server virtualization vendors and their associated products:
VMware ESX Server
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Citrix XenServer
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Microsoft Hyper-V
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Network solutions are needed to solve the challenges of sharing network resources but
keeping users totally separate from one another. Although the users are separate, we still
need to ensure that the network is highly available, secure, and can scale along with the
business growth. Network virtualization offers solutions to these challenges and provides
design considerations around access control, path isolation, and services edge.
