IPv6 Security (Networking Technology Series)

by Scott Hogg, Eric Vyncke

Overview

IPv6 Security

 

Protection measures for the next Internet Protocol

 

As the world’s networks migrate to the IPv6 protocol, networking professionals need a clearer understanding of the security risks, threats, and challenges this transition presents. In IPv6 Security, two of the world’s leading Internet security practitioners review each potential security issue introduced by IPv6 networking and present today’s best solutions.

 

IPv6 Security offers guidance for avoiding security problems prior to widespread IPv6 deployment. The book covers every component of today’s networks, identifying specific security deficiencies that occur within IPv6 environments and demonstrating how to combat them.

 

The authors describe best practices for identifying and resolving weaknesses as you maintain a dual stack network. Then they describe the security mechanisms you need to implement as you migrate to an IPv6-only network. The authors survey the techniques hackers might use to try to breach your network, such as IPv6 network reconnaissance, address spoofing, traffic interception, denial of service, and tunnel injection.

 

The authors also turn to Cisco® products and protection mechanisms. You learn how to use Cisco IOS® and ASA firewalls and ACLs to selectively filter IPv6 traffic. You also learn about securing hosts with Cisco Security Agent 6.0 and about securing a network with IOS routers and switches. Multiple examples are explained for Windows, Linux, FreeBSD, and Solaris hosts. The authors offer detailed examples that are consistent with today’s best practices and easy to adapt to virtually any IPv6 environment.

 

Scott Hogg, CCIE® No. 5133, is Director of Advanced Technology Services at Global Technology Resources, Inc. (GTRI). He is responsible for setting the company’s technical direction and helping it create service offerings for emerging technologies such as IPv6. He is the Chair of the Rocky Mountain IPv6 Task Force.

 

Eric Vyncke, Cisco Distinguished System Engineer, consults on security issues throughout Europe. He has 20 years’ experience in security and teaches security seminars as a guest professor at universities throughout Belgium. He also participates in the Internet Engineering Task Force (IETF) and has helped several organizations deploy IPv6 securely.

 

• Understand why IPv6 is already a latent threat in your IPv4-only network
• Plan ahead to avoid IPv6 security problems before widespread deployment
• Identify known areas of weakness in IPv6 security and the current state of attack tools and hacker skills
• Understand each high-level approach to securing IPv6 and learn when to use each
• Protect service provider networks, perimeters, LANs, and host/server connections
• Harden IPv6 network devices against attack
• Utilize IPsec in IPv6 environments
• Secure mobile IPv6 networks
• Secure transition mechanisms in use during the migration from IPv4 to IPv6
• Monitor IPv6 security
• Understand the security implications of the IPv6 protocol, including issues related to ICMPv6 and the IPv6 header structure
• Protect your network against large-scale threats by using perimeter filtering techniques and service provider—focused security practices
• Understand the vulnerabilities that exist on IPv6 access networks and learn solutions for mitigating each

 

 

This security book is part of the Cisco Press® Networking Technology Series. Security titles from Cisco Press help networking professionals secure critical data and resources, prevent and mitigate network attacks, and build end-to-end self-defending networks.

 

Category: Networking: Security

Covers: IPv6 Security

Product Details

ISBN-13:	9781587058363
Publisher:	Pearson Education
Publication date:	12/11/2008
Series:	Networking Technology: Security
Sold by:	Barnes & Noble
Format:	eBook
Pages:	576
File size:	7 MB
Age Range:	18 Years

About the Author

Scott Hogg, CCIE No. 5133, has been a network computing consultant for more than 17 years. Scott provides network engineering, security consulting, and training services, focusing on creating reliable, high-performance, secure, manageable, and cost-effective network solutions. He has a bachelor’s degree in computer science from Colorado State University and a master’s degree in telecommunications from the University of Colorado. In addition to his CCIE he has his CISSP (No. 4610) and many other vendor and industry certifications. Scott has designed, implemented, and troubleshot networks for many large enterprises, service providers, and government organizations. For the past eight years, Scott has been researching IPv6 technologies. Scott has written several white papers on IPv6 and has given numerous presentations and demonstrations of IPv6 technologies. He is also currently the chair of the Rocky Mountain IPv6 Task Force and the Director of Advanced Technology Services at Global Technology Resources, Inc. (GTRI), a Cisco Gold partner headquartered in Denver, Colorado.

 

Eric Vynckeis a Distinguished System Engineer for Cisco working as a technical consultant for security covering Europe. His main area of expertise for 20 years has been security from Layer 2 to applications. He has helped several organizations deploy IPv6 securely. For the past eight years, Eric has participated in the Internet Engineering Task Force (IETF) (he is the author of RFC 3585). Eric is a frequent speaker at security events (notably Cisco Live [formerly Networkers]) and is also a guest professor at Belgian Universities for security seminars. He has a master’s degree in computer science engineering from the University of Liège in Belgium. He worked as a research assistant in the same university before joining Network Research Belgium, where he was the head of R&D; he then joined Siemens as a project manager for security projects including a proxy firewall. He coauthored the Cisco Press book LAN Switch Security: What Hackers Know About Your Switches. He is CISSP No. 75165.

Table of Contents

In>Chapter 1 Introduction to IPv6 Security

Reintroduction to IPv6 3

IPv6 Update 6

IPv6 Vulnerabilities 7

Hacker Experience 8

IPv6 Security Mitigation Techniques 9

Summary

Recommended Readings and Resources

Chapter 2 IPv6 Protocol Security Vulnerabilities

The IPv6 Protocol Header

    ICMPv6

        ICMPv6 Functions and Message Types

        ICMPv6 Attacks and Mitigation Techniques

    Multicast Security

Extension Header Threats

    Extension Header Overview

    Extension Header Vulnerabilities

    Hop-by-Hop Options Header and Destination Options Header

        IPv6 Extension Header Fuzzing

        Router Alert Attack

    Routing Headers

        RH0 Attack

        Preventing RH0 Attacks

        Additional Router Header Attack Mitigation Techniques

    Fragmentation Header

        Overview of Packet Fragmentation Issues

        Fragmentation Attacks

        Preventing Fragmentation Attacks

        Virtual Fragment Reassembly

    Unknown Option Headers

    Upper-Layer Headers

Reconnaissance on IPv6 Networks

    Scanning and Assessing the Target

        Registry Checking

        Automated Reconnaissance

    Speeding Up the Scanning Process

        Leveraging Multicast for Reconnaissance

        Automated Reconnaissance Tools

        Sniffing to Find Nodes

        Neighbor Cache

        Node Information Queries

    Protecting Against Reconnaissance Attacks

Layer 3 and Layer 4 Spoofing

Summary

References

Chapter 3 IPv6 Internet Security

Large-Scale Internet Threats

    Packet Flooding

    Internet Worms

        Worm Propagation

        Speeding Worm Propagation in IPv6

        Current IPv6 Worms

        Preventing IPv6 Worms

    Distributed Denial of Service and Botnets

        DDoS on IPv6 Networks

        Attack Filtering

        Attacker Traceback

        Black Holes and Dark Nets

Ingress/Egress Filtering

    Filtering IPv6 Traffic

    Filtering on Allocated Addresses

    Bogon Filtering

    Bogon Filtering Challenges and Automation

Securing BGP Sessions

    Explicitly Configured BGP Peers

    Using BGP Session Shared Secrets

    Leveraging an IPsec Tunnel

    Using Loopback Addresses on BGP Peers

    Controlling the Time-to-Live (TTL) on BGP Packets

    Filtering on the Peering Interface

    Using Link-Local Peering

        Link-Local Addresses and the BGP Next-Hop Address

        Drawbacks of Using Link-Local Addresses

    Preventing Long AS Paths

    Limiting the Number of Prefixes Received

    Preventing BGP Updates Containing Private AS Numbers

    Maximizing BGP Peer Availability

        Disabling Route-Flap Dampening

        Disabling Fast External Fallover

        Enabling Graceful Restart and Route Refresh or Soft Reconfiguration

        BGP Connection Resets

    Logging BGP Neighbor Activity

    Securing IGP

    Extreme Measures for Securing Communications Between BGP Peers

IPv6 over MPLS Security

    Using Static IPv6 over IPv4 Tunnels Between PE Routers

    Using 6PE

    Using 6VPE to Create IPv6-Aware VRFs

Customer Premises Equipment

Prefix Delegation Threats

    SLAAC

    DHCPv6

Multihoming Issues

Summary

References

Chapter 4 IPv6 Perimeter Security

IPv6 Firewalls

    Filtering IPv6 Unallocated Addresses

    Additional Filtering Considerations

        Firewalls and IPv6 Headers

        Inspecting Tunneled Traffic

        Layer 2 Firewalls

        Firewalls Generate ICMP Unreachables

        Logging and Performance

    Firewalls and NAT

Cisco IOS Router ACLs

    Implicit IPv6 ACL Rules

    Internet ACL Example

    IPv6 Reflexive ACLs

Cisco IOS Firewall

    Configuring IOS Firewall

    IOS Firewall Example

    IOS Firewall Port-to-Application Mapping for IPv6

Cisco PIX/ASA/FWSM Firewalls

    Configuring Firewall Interfaces

    Management Access

    Configuring Routes

    Security Policy Configuration

    Object Group Policy Configuration

    Fragmentation Protection

    Checking Traffic Statistics

    Neighbor Discovery Protocol Protections

Summary

References

Chapter 5 Local Network Security

Why Layer 2 Is Important

ICMPv6 Layer 2 Vulnerabilities for IPv6

    Stateless Address Autoconfiguration Issues

    Neighbor Discovery Issues

    Duplicate Address Detection Issues

    Redirect Issues

ICMPv6 Protocol Protection

    Secure Neighbor Discovery

    Implementing CGA Addresses in Cisco IOS

    Understanding the Challenges with SEND

Network Detection of ICMPv6 Attacks

    Detecting Rogue RA Messages

    Detecting NDP Attacks

Network Mitigation Against ICMPv6 Attacks

    Rafixd

    Reducing the Target Scope

    IETF Work

    Extending IPv4 Switch Security to IPv6

Privacy Extension Addresses for the Better and the Worse

DHCPv6 Threats and Mitigation

    Threats Against DHCPv6

    Mitigating DHCPv6 Attacks

        Mitigating the Starvation Attack

        Mitigating the DoS Attack

        Mitigating the Scanning

        Mitigating the Rogue DHCPv6 Server

Point-to-Point Link

Endpoint Security

Summary

References

Chapter 6 Hardening IPv6 Network Devices

Threats Against Network Devices

Cisco IOS Versions

Disabling Unnecessary Network Services

    Interface Hardening

Limiting Router Access

    Physical Access Security

    Securing Console Access

    Securing Passwords

    VTY Port Access Controls

    AAA for Routers

    HTTP Access

IPv6 Device Management

    Loopback and Null Interfaces

    Management Interfaces

    Securing SNMP Communications

Threats Against Interior Routing Protocol

    RIPng Security

    EIGRPv6 Security

    IS-IS Security

    OSPF Version 3 Security

First-Hop Redundancy Protocol Security

    Neighbor Unreachability Detection

    HSRPv6

    GLBPv6

Controlling Resources

    Infrastructure ACLs

    Receive ACLs

    Control Plane Policing

QoS Threats

Summary

References

Chapter 7 Server and Host Security

IPv6 Host Security

    Host Processing of ICMPv6

    Services Listening on Ports

        Microsoft Windows

        Linux

        BSD

        Sun Solaris

    Checking the Neighbor Cache

        Microsoft Windows

        Linux

        BSD

        Sun Solaris

    Detecting Unwanted Tunnels

        Microsoft Windows

        Linux

        BSD

        Sun Solaris

    IPv6 Forwarding

        Microsoft Windows

        Linux

        BSD

        Sun Solaris

    Address Selection Issues

        Microsoft Windows

        Linux

        BSD

        Sun Solaris

Host Firewalls

    Microsoft Windows Firewall

    Linux Firewalls

    BSD Firewalls

        OpenBSD Packet Filter

        ipfirewall

        IPFilter

    Sun Solaris

Securing Hosts with Cisco Security Agent 6.0

Summary

References

Chapter 8 IPsec and SSL Virtual Private Networks

IP Security with IPv6

    IPsec Extension Headers

    IPsec Modes of Operation

    Internet Key Exchange (IKE)

        IKE Version 2

    IPsec with Network Address Translation

    IPv6 and IPsec

Host-to-Host IPsec

Site-to-Site IPsec Configuration

    IPv6 IPsec over IPv4 Example

        Configuring IPv6 IPsec over IPv4

        Verifying the IPsec State

        Adding Some Extra Security

        Dynamic Crypto Maps for Multiple Sites

    IPv6 IPsec Example

        Configuring IPsec over IPv6

        Checking the IPsec Status

    Dynamic Multipoint VPN

        Configuring DMVPN for IPv6

        Verifying the DMVPN at the Hub

        Verifying the DMVPN at the Spoke

Remote Access with IPsec

SSL VPNs

Summary

References

Chapter 9 Security for IPv6 Mobility

Mobile IPv6 Operation

MIPv6 Messages

    Indirect Mode

    Home Agent Address Determination

    Direct Mode

Threats Linked to MIPv6

    Protecting the Mobile Device Software

    Rogue Home Agent

    Mobile Media Security

    Man-in-the-Middle Threats

    Connection Interception

    Spoofing MN-to-CN Bindings

    DoS Attacks

Using IPsec with MIPv6

Filtering for MIPv6

    Filters at the CN

    Filters at the MN/Foreign Link

    Filters at the HA

Other IPv6 Mobility Protocols

    Additional IETF Mobile IPv6 Protocols

    Network Mobility (NEMO)

    IEEE .16e

    Mobile Ad-hoc Networks

Summary

References

Chapter 10 Securing the Transition Mechanisms

Understanding IPv4-to-IPv6 Transition Techniques

    Dual-Stack

    Tunnels

        Configured Tunnels

        6to4 Tunnels

        ISATAP Tunnels

        Teredo Tunnels

        6VPE

    Protocol Translation

Implementing Dual-Stack Security

    Exploiting Dual-Stack Environment

    Protecting Dual-Stack Hosts

Hacking the Tunnels

    Securing Static Tunnels

    Securing Dynamic Tunnels

        6to4

        ISATAP

        Teredo

    Securing 6VPE

Attacking NAT-PT

IPv6 Latent Threats Against IPv4 Networks

Summary

References

Chapter 11 Security Monitoring

Managing and Monitoring IPv6 Networks

    Router Interface Performance

    Device Performance Monitoring

        SNMP MIBs for Managing IPv6 Networks

        IPv6-Capable SNMP Management Tools

        NetFlow Analysis

    Router Syslog Messages

    Benefits of Accurate Time

Managing IPv6 Tunnels

Using Forensics

Using Intrusion Detection and Prevention Systems

    Cisco IPS Version 6.1

    Testing the IPS Signatures

Managing Security Information with CS-MARS

Managing the Security Configuration

Summary

References

Chapter 12 IPv6 Security Conclusions

Comparing IPv4 and IPv6 Security

    Similarities Between IPv4 and IPv6

    Differences Between IPv4 and IPv6

Changing Security Perimeter

Creating an IPv6 Security Policy

    Network Perimeter

    Extension Headers

    LAN Threats

    Host and Device Hardening

    Transition Mechanisms

    IPsec

    Security Management

On the Horizon

Consolidated List of Recommendations

Summary

References

Preface

Introduction

Internet Protocol version 6 (IPv6) is the next version of the protocol that is used for communications on the Internet. IPv6 is a protocol that has been in existence for many years, but it has not yet replaced IPv4. IPv4 has some limitations that were not anticipated when it was first created. Because IPv6 overcomes many of these limitations, it is the only viable long-term replacement for IPv4.

While the migration to IPv6 has started, it is still in its early stages. Many international organizations already have IPv6 networks, the U.S. federal organizations are working on their transitions to IPv6, and others are contemplating what IPv6 means to them. However, many organizations already have IPv6 running on their networks and they do not even realize it. Many computer operating systems now default to running both IPv4 and IPv6, which could cause security vulnerabilities if one is less secure than the other. IPv6 security vulnerabilities currently exist, and as the popularity of the IPv6 protocol increases, so do the number of threats.

When a security officer wants to secure an organization, he must be aware of all potential threats, even if this threat is a ten-year-old protocol that represents less than 1 percent of the overall Internet traffic in 2008. Don’t be blinded by this 1 percent: This figure is doomed to increase in the coming years, and chances are good that your network is already exposed to some IPv6 threats. It’s better to be safe than sorry.

Just like the early deployment of many technologies, security is often left to the final stages of implementation. Our intent in writing this book is to improve the security of early IPv6 deployments from day one. Any organization considering or already in the midst of transitioning to IPv6 does not want to deploy a new technology that cannot be secured right from the outset. The transition to IPv6 is inevitable, and therefore this book can help you understand the threats that exist in IPv6 networks and give you ways to protect against them. Therefore, this book gives guidance on how to improve the security of IPv6 networks.

Goals and Methods

Currently, many organizations have slowed their migration to IPv6 because they realize that the security products for IPv6 might be insufficient, despite the fact that the network infrastructure is ready to support IPv6 transport. They realize that they cannot deploy IPv6 without first considering the security of this new protocol. This book intends to survey the threats against IPv6 networks and provide solutions to mitigate those threats. It covers the issues and the best current practices.

This book is arranged so that it covers the threats first and then describes ways to combat these threats. By outlining all the risks and showing that a solution exists for each threat, you can feel more comfortable with continuing the transition to IPv6. You learn about techniques attackers might use to breach your networks and what Cisco products to use to protect the networks.

However, showing attacks without solutions is socially irresponsible, so the focus is on the current techniques that are available to make the IPv6 network more secure and on the best current practices.

By reading this book, you can gain an understanding of the full range of IPv6 security topics.

Who Should Read This Book

This book is intended to be read by people in the IT industry who are responsible for securing computer networks. You should already know the basics of the IPv6 protocol and networking technology. This book is not an introduction to IPv6. There are many good books and online resources that can teach you about IPv6, and there are many great books on computer network security.

The intent of this book is to dive deeper into the protocol and discuss the protocol details from a security practitioner’s perspective. It is a book for experts by experts. It covers the theory but at the same time gives practical examples that can be implemented.

How This Book Is Organized

This book starts with a foundation of the security aspects of the IPv6 protocol. The early topics of this book are arranged from the outward perimeter of an organization’s network inward to the LAN and server farms. The later chapters of the book cover advanced topics. This book can be read completely from start to finish; however, if you want to “skip around,” that is fine. You should eventually read every chapter to gain a comprehensive knowledge of the subject matter.

Some of the information (such as tables and commands) in this book is for reference. You should refer back to this book when it comes time to implement. This gives you cookie-cutter examples to follow that should be in line with the best current practices for securing IPv6. However, do not just go through this book and implement every command listed. Perform some of your own basic research on these commands to make sure that they perform exactly what you intend your network to do.

IPv6 security is an incredibly active research area, and new protocols and new products will continually be developed after this book is written. It is our goal that the “shelf life” of this book is many years because the concepts will still be valid even as Cisco security products continue to evolve with the threat landscape. Every effort was made to make this book as current as possible at the time it was published, but you are advised to check whether new methods are available at the time of reading. The IPv6 security field is quickly evolving as IPv6 gets more widely deployed.

Chapters 1 through 12 cover the following topics:

• Chapter 1, “Introduction to IPv6 Security”: This short chapter reintroduces IPv6, describes how widely it is deployed, discusses its vulnerabilities, and identifies what hackers already know about IPv6. Some initial mitigation techniques are presented.
• Chapter 2, “IPv6 Protocol Security Vulnerabilities”: This chapter discusses the aspects of the IPv6 protocol itself that have security implications. Security issues related to ICMPv6 and the IPv6 header structure are covered. Demonstrations are conducted that show the protocol vulnerabilities, and solutions are given to mitigate those risks. This chapter also covers security issues of IPv6 network reconnaissance and address spoofing.
• Chapter 3, “IPv6 Internet Security”: This chapter covers the large-scale threats against the IPv6 Internet and describes perimeter-filtering techniques that can help protect against those threats. Security for BGP peering is detailed in addition to other service provider–focused security practices. IPv6 MPLS security, security of customer equipment, IPv6 prefix delegation, and multihoming are reviewed.
• Chapter 4, “IPv6 Perimeter Security”: This chapter covers the security threats that exist for perimeter networks that utilize IPv6. The chapter covers common filtering techniques that are deployed at the perimeter of the network. This chapter also covers IPv6 access lists, the IOS Firewall feature set, and the PIX/ASA/FWSM firewalls.
• Chapter 5, “Local Network Security”: This chapter examines the threats against LANs. Many vulnerabilities exist on IPv6 access networks, and these vulnerabilities are covered along with many solutions for mitigating them. The chapter covers issues related to Neighbor Discovery Protocol, autoconfiguration addressing, and DHCPv6 communications on a LAN. This chapter also reviews SEND and describes how it can be implemented.
• Chapter 6, “Hardening IPv6 Network Devices”: This chapter covers the security improvements that can be made to a network device running IPv6. Techniques for securing the management of network devices are reviewed. This chapter reviews ways to secure routing protocols and covers first-hop router redundancy protocols. Techniques for controlling the device’s resources are detailed in addition to ways to control network traffic.
• Chapter 7, “Server and Host Security”: This chapter covers the ways to secure a computer running IPv6. It is important to harden IPv6 nodes from the threats that exist. Microsoft, Linux, BSD, and Solaris operating system IPv6 security techniques are detailed. This chapter covers how host-based firewalls and Cisco Security Agent (CSA) can be used to protect IPv6 hosts.
• Chapter 8, “IPsec and SSL Virtual Private Networks”: This chapter covers the basics of IPsec. The chapter reviews techniques for setting up site-to-site VPN links using IPv6, dynamic multipoint VPNs, as well as remote-access VPNs. The use of ISATAP over an IPsec client connection and the use of SSL VPNs with AnyConnect client are covered.
• Chapter 9, “Security for IPv6 Mobility”: This chapter covers Mobile IPv6 and describes how securing this protocol can be challenging. Mobile IPv6 is reviewed, and the security implications are discussed. This chapter gives recommendations on how Mobile IPv6 can be used responsibly and safely. Additional IPv6-capable mobility solutions are covered along with their security implications.
• Chapter 10, “Securing the Transition Mechanisms”: This chapter discusses the various techniques that are used to help organizations migrate from IPv4 to IPv6. Dual-stack, tunnel, and NAT migration techniques are covered along with their security issues. Each of these techniques has its own security implications and solutions for securing the traffic. This chapter covers the threats by showing examples of how an attacker might try to infiltrate a network. The security protections that can be used to keep the network safe during migration are also covered.
• Chapter 11, “Security Monitoring”: This chapter covers the various systems that are currently available to monitor the security of IPv6 networks. Monitoring a network and the computers on the network is a critical aspect of any security practice. IPv6 networks are the same in this regard and must be managed appropriately. The topics of forensics, intrusion detection and prevention, security information management, and configuration management are covered.
• Chapter 12, “IPv6 Security Conclusions”: This chapter summarizes the common themes discussed throughout the book. Commonalities between IPv4 security and IPv6 security are discussed. This chapter contains discussions about creating IPv6-specific security policies. This chapter also reviews what the future holds for IPv6 security. A consolidated list of IPv6 security recommendations is provided.

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