You are on page 1of 8

.

White Paper

Network Services Virtualization

What Is Network Virtualization?
Business and IT leaders require a more responsive IT infrastructure that can help accelerate business initiatives and
remove inefficiencies. To meet this challenge, the IT infrastructure needs to be based on an IT model with a new
services delivery architecture that enables services as needed. It needs to evolve from a traditional campus
architecture that delivers basic connectivity to separate, siloed departments into an agile, resilient, and adaptive
architecture that delivers service orchestration. With these changes, the IT department becomes a business unit that
delivers services to improve the enterprise rather than simply a cost center. The technology that helps deliver this
new dynamic IT infrastructure is called Network Virtualization (Figure 1).

Figure 1. Network Virtualization

Business Challenges
In this new economy of globally distributed workforces and global competition, enterprises continue to use
collaborative technologies to help connect geographically dispersed user groups so that they act and feel like a
single, centralized entity. These collaborative technologies improve employee productivity while reducing operating
expenses by creating the notion of a borderless enterprise in which employees, customers, and partners all share
significant information and connect their business processes efficiently.

© 2009 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information. Page 1 of 8

© 2009 Cisco Systems. achieving better device utilization. It has been widely deployed as part of data center network designs and is seeing increasing adoption in campus networks. White Paper Adoption of collaborative technologies demands the network infrastructure to: ● Be agile: IT leaders are looking for ways to be more responsive to changing market dynamics. Network virtualization architecture has three main components (Figure 2): ● Network access control and segmentation of classes of users: Users are authenticated and either allowed or denied into a logical partition. Cisco Network Virtualization Architecture The concept of virtualization is not new and has been employed since the days of mainframe computers. requiring them to accelerate deployment of new applications such as video conferencing equipment to help reduce travel costs. Inc. with ubiquitous devices and omnipresent users: Users expect more control over when and how they work. with respective access to IT assets. All rights reserved. ● Connect a globally distributed workforce. To accomplish this. contractors and consultants. It also applies policy per partition and isolates application environments. Page 2 of 8 . with an increasing emphasis on service delivery. Network services virtualization within the campus helps IT focus on providing a unique set of policies to different network segments without having to deploy dedicated service nodes. ● Path isolation: Network isolation is preserved across the entire enterprise: from the edge to the campus to the WAN and back again. This document is Cisco Public Information. The function of mapping isolated paths to VLANs and to virtual services is also performed in component. This component identifies users who are authorized to access the network and then places them into the appropriate logical partition. and address management (Dynamic Host Configuration Protocol [DHCP] and Domain Name System [DNS]). if required. and guests. This component maintains traffic partitioned over a routed infrastructure and transports traffic over and between isolated partitions. Users are segmented into employees. ● Reduce operating expenses: IT needs to increase asset utilization and simplify services provisioning. keeping them separate and secure is a challenge that IT leaders must continue to address. ● Network Services virtualization: This component provides access to shared or dedicated network services such as security. quality of service (QoS). ● Manage growth in user groups that need similar services: As the number of groups increases. ● Become energy efficient: IT needs to control the power and cooling requirements for the network infrastructure and service nodes. they are looking at new service delivery options that can provide incremental services on the same infrastructure.

users see: ◦ Reduced total cost of ownership (TCO) and increased return on investment (ROI) through improved asset utilization. Cisco Network Virtualization Architecture What Is Network Services Virtualization? Network services virtualization is a critical building block in network virtualization. Although all the building blocks can be deployed in isolation. Page 3 of 8 . The service virtualization provides independent instances of name space. for example. network services virtualization is an excellent strategy for consolidating multiple appliances into one. further. White Paper Figure 2. inspection engines. and other resources within each instance. Network services virtualization negates the need to acquire separate devices every time the network service is required by using the software instance on ® the same physical hardware. simplifying network operations and reducing overall acquisition cost. configuration. Some implementations such as the Cisco Catalyst 6500 Series Firewall Services Module (FWSM) can support nearly 250 separate virtual firewall instances. extending its access without the need to deploy specialized hardware for every instance of the network service that is required. by partitioning the available hardware resources among different virtual firewalls. giving the end user greater flexibility in deploying the right number of virtual instances. From an expense-management perspective. This document is Cisco Public Information. Inc. Network services virtualization virtualizes a network service node such as a firewall module. All rights reserved. achieved by enabling additional capabilities within existing infrastructure ◦ Pay-as-you-grow licensing model for the virtualized service. it is easy to scale to a greater number of instances if future needs increase © 2009 Cisco Systems. Network services virtualization provides numerous business and IT benefits: ● Efficient utilization: Acquisition cost is reduced as network services delivery is removed from a physical device to a virtual context.

and complexity in upgrading. Its choices are to share everything or nothing. Network Services Virtualization – Cisco Catalyst 6500 Virtualized network services available on the Cisco Catalyst 6500 series platform include: ● Network security virtualization through multicontext virtual firewall contexts. Page 4 of 8 . a virtual service node instance can be created on the same physical infrastructure without the need for additional network cabling. and device configuration is complex. ● Virtual Route Forwarding (VRF) network services: VRF-aware network services include: ◦ VRF-Aware Address anagement services. The overall system resources within a single physical firewall can be administrated separated for other contexts. Adding more physical service nodes creates an inefficient isolation of applications and results in device sprawl. This segmentation of network services helps ensure that the security. operating expenditures (OpEx). © 2009 Cisco Systems. This document is Cisco Public Information. secure applications with essentially guaranteed resources and role-based access. facilitating operational manageability Network Security Virtualization: Firewalls Network security using firewalls has evolved from a process that limit access to secure data and networks beginning with simple access lists to a technology that provides context-based stateful application inspection capabilities. changes to one policy can affect the others. enabling isolated. VRF-aware DHCP helps enable pervasive DHCP policies for groups of geographically dispersed users ◦ Optimized traffic redirection using VRF-aware Policy-Based Routing (PBR) and PBR-set VRF ◦ Facilitating operational manageability with VRF-aware syslog and VRF Aware Telnet. and rack space that would otherwise have been required. The management interface becomes more flexible as many network service instances can be managed as one. and power requirements. ● Manageability: Virtual service instances offer simplified provisioning. underutilized resources. With the network service virtualization approach. All rights reserved. abstraction and partitioning allow one physical network service node to provide multiple virtual contexts. Office of the Controller of the Currency (OCC) rules. a firewall). also called security contexts: Each security context is an independent firewall with its own security policy. interfaces. To enable a particular service within existing siloed infrastructure requires addition of network infrastructure equipment and changes to network cabling. This approach results in dramatic reductions in provisioning cycles. and administrators. ● Regulatory compliance: Compliance with regulations such as Health Insurance Portability and Accountability Act (HIPAA). Eliminating the need for additional physical devices effectively removes the need for additional power supplies. White Paper ● Green: Reduced power consumption is achieved by consolidating multiple service instances into a single physical device without requiring deployment of dedicated hardware for each instance. This system resource administration is required to make sure that no context inadvertently affects another context. cooling. Network Services Virtualization: Before and After Consider a typical enterprise before it implements virtualization. If it uses a single physical services node (for example. such as that enabled by Cisco products. ® With a virtualized architecture. and Sarbanes-Oxley require customers to segment their network services on a group basis. or each instance can have its own. Inc. and traffic path manipulation of one group is different from the other groups within the enterprise. QoS. applications must compete for resources. separate management interface. .

Each virtual context has its own set of virtual interfaces to which the security policies can be applied.1q VLAN tags on the same physical interface. Virtualization at the next level involves partitioning a single physical firewall into multiple virtual firewalls. or they can all be managed by one administrator who has access to each of the contexts.1q support on firewalls allows customers to easily integrate into existing networks that have already been segmented using VLANs (IEEE 802. interfaces. All rights reserved. This document is Cisco Public Information. known as the security contexts. Virtualization techniques have evolved far beyond traditional VLAN integration. Each security context is an independent firewall. Inc. Each virtual firewall is called a context because it is one partition or instance of a fully functional firewall. and memory to each of the contexts based on customer needs and the needs of each group. to run independently and simultaneously on the same physical firewall hardware module. Therefore. and administrators. or stealth) as well as mixed-mode firewalls. IEEE 802. the firewall applies a single set of policies for traffic traveling between the inside and the outside interface (Figure 3). IT managers can also allocate the firewall’s shared resources such as bandwidth. Page 5 of 8 . Conventional Firewalls Firewall Virtualization: Virtualization in its simplest form can be achieved by supporting IEEE 802. Cisco Catalyst 6500 Series FWSM Virtualization Architecture The Cisco Catalyst 6500 Series Firewall Services Module allows the customer to configure up to 250 mixed-mode multiple virtual firewalls. Each individual context can be configured based on the group’s security policies without affecting other contexts. These contexts can be routed firewalls (Layer 3) or transparent firewalls (Layer 2. Today’s virtualization technologies enable an abstraction layer that decouples the security policies from the physical hardware to deliver greater network resource utilization and flexibility. IT departments managing internal campus networks can now partition a physical firewall into multiple contexts for each group of users (either segmenting them by role or by business unit) without investing in a dedicated physical firewall for each group. Figure 3. as if being handled by a dedicated physical firewall. Multiple firewall contexts can be added in the module on the basis of the license © 2009 Cisco Systems. the traffic inspection and security policies of each context are independent of each other. which are a combination of both Layer 2 and Layer 3 firewalls coexisting on the same physical firewall. each context can be configured and managed by different administrators. White Paper Evolution to Firewall Virtualization: Conventional Stand-alone Firewalls: Conventional firewalls allow users to apply security policies on the data passing between networks (that is. with heterogeneous security policies. Targeted Firewall Virtualization Applications Multiple security contexts are useful for both enterprise campus and data center deployments. The capability to run multiple security contexts on single Cisco Catalyst 6500 Series FWSMs helps customers limit the cost of additional hardware. In the conventional firewall case. Virtualization allows multiple virtual machines.1q VLANs). the interfaces of a firewall). total connections. with its own security policy. Even though all the configured contexts are emulated by a single firewall CPU.

© 2009 Cisco Systems. Page 6 of 8 . Firewall Virtualization Figure 6 shows how a single Cisco Catalyst 6500 Series FWSM can be organized into multiple security contexts. the administrator can allocate system resources such as connections and seconds as a percentage or an absolute number for each individual context. Figure 4. Single Firewall Before Virtualization Figure 5. Inc. Figures 4 and 5 show how the internal architecture of the Cisco Catalyst 6500 Series FWSM functions before and after virtualization. creating virtual firewalls (VFs). White Paper limits. This document is Cisco Public Information. both routed and transparent. All rights reserved. To effectively share the system resources across all contexts.

White Paper Figure 6. Main functions include: ● Ease of operational manageability within VRF instances: The Cisco Catalyst 6500 Series supports features that enable switch management within a VRF instance. Page 7 of 8 . Virtualized Firewall Network Services Virtualization: VRF-Aware Services The Cisco Catalyst 6500 and 4500 Series Switches enable VRF support for features that help provide network services. This document is Cisco Public Information. Inc. Main features include: ◦ NetFlow on VRF interfaces: Allows NetFlow statistics collection on interfaces that are part of a VRF instance ◦ VRF-aware syslog: Allows the switch to send system logging (syslog) messages to a syslog server host connected through a VRF interface ◦ VRF-aware Telnet: Allows the management interface to be part of a VRF instance instead of the global interface list © 2009 Cisco Systems. All rights reserved.

Inc. Network Services Virtualization design guides: http://www.cisco. making it easier and faster to enable new network services.com/en/US/docs/solutions/Enterprise/Network_Virtualization/ServEdge. Conclusion Cisco offers a proven. For More Information Go online to learn more about Cisco Network virtualization solutions: www. ● Optimized traffic redirection using PBR-set VRF: This feature helps segment and redirect traffic from the global routing table to a VRF instance. and accounting (AAA) TACACS server to be part of the VRF instance. The Cisco Catalyst 6500 platform is a key component of the Cisco Network Virtualization architecture which allows customers to manage the networks services. Page 8 of 8 . end-to-end Network virtualization solution that spans the entire network infrastructure. mobility. authorization. from the backbone to every endpoint. The Cisco Catalyst 6500 has a broad range of hardware and software features that enable customers to deploy virtualization across all places in the network to help reduce the management complexity of services including Unified Communications. All rights reserved. the switch should be able to send AAA messages to an AAA server within a VRF instance ● Virtualized address management policies using VRF-aware DHCP: This feature helps enable pervasive DHCP policies for groups of geographically dispersed users. This shared services architecture enables flexibility and agility while streamlining resources and reducing operational expenses.html Printed in USA C11-531522-00 04/09 © 2009 Cisco Systems. Using the Cisco Network Virtualization architecture. This document is Cisco Public Information. organizations can reap the benefits of end-to-end virtualization and policy-driven service orchestration.cisco. White Paper ◦ VRF-aware TACACS: Allows the authentication.com/go/networkvirtualization. and security.