Network Virtualization

Description

Share network resources and reduce costs while providing secure network services to diverse user communities

• Presents the business drivers for network virtualization and the major challenges facing network designers today
• Shows how to use virtualization designs with existing applications, such as VoIP and network services, such as quality of service and multicast
• Provides design alternatives for different real-world deployment scenarios, with configuration examples and case studies 

Today's enterprises have several groups of users with specific needs. The differences between these groups translate into specific network requirements. Within some organizations, these requirements are so dissimilar that the different groups need to be treated as totally separate customers by the enterprise's IT department. As the number of groups increases, keeping them separate and secure is a challenge to IT departments, particularly with the advent of wireless networks, the requirement for enterprise-wide user mobility, and the need for cross group collaboration with resource sharing on a per project basis. Network Virtualization provides design guidance for virtualized enterprise networks and arms network architects with the background necessary to make sound technological choices in the face of different business requirements. As a means of introduction, Network Virtualization lays out the fundamentals of enterprise network design. The book builds upon these fundamental principles to introduce the different virtualization methods as the logical evolution of the enterprise network architecture. Detailed descriptions of the technology, design principles, network configurations, and real-world case studies are provided throughout the book, helping readers develop a pragmatic understanding of virtualized enterprise network architectures. Specific examples are included that tailor deployment advice to the small, medium, and large enterprise environment.

 

 

Table of Contents

Table of Contents

Introduction

Part  I A Network Architecture for the Virtual Enterprise3

Chapter 1 Business Drivers Behind Enterprise Network Virtualization

Why Virtualize?

Visitors, Partners, Contractors, and Quarantine Areas

Regulatory Compliance

Secure Service Areas

Network Consolidation

Acquisitions and Mergers

Multitenant Enterprises

Virtual Project Environment: Next-Generation Business Processes

Business Requirements Drive Technical Requirements

Summary

Chapter 2 Designing Scalable Enterprise Networks

Hierarchical Campus Design

Virtualizing the Campus

WAN Design

WAN Provider Service Offerings

WAN Architecture

WAN Resiliency

WAN Routing Considerations

Securing the WAN

WAN Virtualization

Summary

Chapter 3 Basic Virtualized Enterprise

The Virtual Enterprise

Transport Virtualization–VNs

VLANs and Scalability

Virtualizing the Routed Core

The LAN Edge: Authentication and Authorization

Central Services Access: Virtual Network Perimeter

Unprotected Services

Summary

Chapter 4 A Virtualization Technologies Primer: Theory

Network Device Virtualization

Layer 2: VLANs

Layer 3: VRF Instances

Layer 2 Again: VFIs

Virtual Firewall Contexts

Network Device Virtualization Summary

Data-Path Virtualization

Layer 2: 802.1q Trunking

Generic Routing Encapsulation

IPsec

L2TPv3

Label Switched Paths

Data-Path Virtualization Summary

Control-Plane Virtualization–Routing Protocols

VRF-Aware Routing

Multi-Topology Routing

Control-Plane Virtualization Summary

Summary

Chapter 5 Infrastructure Segmentation Architectures: Theory

Hop to Hop

Layer 3 H2H

Single Address Space Alternatives

H2H Summary

Tunnel Overlay for L3VPN

L3VPN Using GRE and IPsec Overlay

Putting It All Together: DMVPN

Layer 3 Tunnel Summary

Tunnel Overlay for Layer 2 VPNs

Layer 2 P2P Overlay Using L2TPv3

Layer 2 P2P Overlay Using MPLS

Layer 2 VPN MP2MP Using MPLS (VPLS)

Layer 2 VPN Summary

Peer-Based Model for Layer 3 VPNs

RFC 2547bis the MPLS Way

RFC 2547bis Forwarding-Plane Alternatives

Inter-Autonomous System Connectivity: Another Application of Tunnels

Carrier Supporting Carrier

Inter-Autonomous System Routing

Inter-Autonomous System Connectivity Summary

Summary

Part  II Enterprise Virtualization Techniques and Best Practices

Chapter 6 Infrastructure Segmentation Architectures: Practice

Hop-to-Hop VLANs

Layer 3 Hop to Hop

Single Address Space Solutions

Tunnel Overlay for Layer 3 VPNs

GRE Tunnels

Multipoint GRE Tunnels

Mapping Traffic to Tunnels

Resiliency and Routing Considerations

Encryption Considerations

Layer 3 VPNs

RFC 2547bis the MPLS Way

RFC 2547bis over L2TPv3

RFC 2547bis over GRE

IGP Best Practices

BGP Best Practices: Route Reflectors

BGP Best Practices: Route Distinguishers and ECMP Routing

Migration Recommendations

Layer 2 VPNs

Ethernet over MPLS

VPLS

Summary 

Chapter 7 Extending the Virtualized Enterprise over the WAN

WAN Services

IP Services

Layer 2 Circuits

P2P GRE

Multipoint GRE

Dynamic Multipoint VPN

Extending Segmentation over the WAN

MPLS over Layer 2 Circuits

VRF-to-VRF Connections at the Autonomous System Border Routers

MP-eBGP Exchange of Labeled VPN-IPv4 Routes Between Adjacent ASBRs

Multihop MP-eBGP Between Remote Autonomous Systems

Using MPLS over Layer 2 Circuits for Segmented Branch Aggregation

Benefits and Drawbacks

Contracting Multiple IP VPNs

Benefits and Drawbacks

Carrier Supporting Carrier (CsC)

Using CsC for Segmented Branch Aggregation

Benefits and Drawbacks

MPLS over GRE

Benefits and Drawbacks

RFC 2547 VPNs over L2TPv3 Tunnels

Benefits and Drawbacks

VRFs Interconnected by a GRE or DMVPN Overlay

Benefits and Drawbacks

RFC 2547 VPNs over DMVPN

Benefits and Drawbacks

Summary

Chapter 8 Traffic Steering and Service Centralization

Shared Services: Protected vs. Unprotected

Unprotected Services

Protected Services

Unprotected Services Access

Basic Import/Export Mechanism

Any-to-Any and Hub-and-Spoke VPNs

Extranet VPN

Localized Inter-VPN Communication

Leaking Traffic with the Global Table

Protected Services Access

Firewalling for Common Services

Routed Firewalls and Transparent Firewalls

Routed Firewall Deployments

Transparent Firewall Deployments

Providing IP Services

DHCP

Domain Name System (DNS) Services

Summary

Chapter 9 Multicast in a Virtualized Environment

Multicast Introduction

Internet Group Management Protocol (IGMP)

Multicast Routing

Protocol Independent Multicast (PIM)

VRFs and Multicast

Multicast Sourced from an External IP Network

Multicast Across VRFs (mVPN Extranet)

mVPN Transport

Global

Tunnel Overlay

mVPN

Connecting the WAN

Summary

Chapter 10 Quality of Service in a Virtualized Environment

QoS Models and Mechanisms: A Review

Differentiated Services

MPLS Quality of Service

Tunnels and Pipes

MPLS Traffic Engineering and Guaranteed Bandwidth

DS-TE and Guaranteed Bandwidth

Do I Really Need This in an Enterprise Network?

QoS Models for Virtualized Networks

One Policy per Group

Summary

Chapter 11 The Virtualized Access Layer

Access Layer Switching

Implementing Dynamic Authentication and Authorization

Clientless Authentication

Client-Based Layer 2

Virtualizing the Access Layer

Layer 3 Access

Summary

Part III Appendixes

Appendix A L2TPv3 Expanded Coverage

L2TPv3 Control Channel

L2TPv3 Data Channel

Appendix B MPLS QoS, Traffic Engineering, and Guaranteed Bandwidth

MPLS QoS–Uniform Tunnel and Pipe Modes

MPLS Traffic Engineering

MPLS Fast Reroute

Guaranteed Bandwidth

Appendix C Recommended Reading

Appendix D RFCs and Internet Drafts

Index