Skip to content

IPv6 and Leaky Addresses

18 November 2019 |

One of the recurring myths of IPv6 is its very large address space somehow confers a higher degree of security. The theory goes something like this: there is so much more of the IPv6 address space to test in order to find out what is connected to the network, it would take too long to scan the entire space looking for devices. The first problem with this myth is it simply is not true—it is quite possible to scan the entire IPv6 address space rather quickly, probing enough addresses to perform a tree-based search to find attached devices. The second problem is this assumes the only modes of attack available in IPv4 will directly carry across to IPv6. But every protocol has its own set of tradeoffs, and therefore its own set of attack surfaces.

IPv6 Backscatter and Address Space Scanning

9 October 2019 | Comments Off on IPv6 Backscatter and Address Space Scanning

Backscatter is often used to detect various kinds of attacks, but how does it work? The paper under review today, Who Knocks at the IPv6 Door, explains backscatter usage in IPv4, and examines how effectively this technique might be used to detect scanning of IPv6 addresses, as well. Scanning the IPv6 address space is much more difficult because there are 2128 addresses rather than 232. The paper under review here is one of the first attempts to understand backscatter in the IPv6 address space, which can lead to a better understanding of the ways in which IPv6 scanners are optimizing their search through the larger address space, and also to begin understanding how backscatter can be used in IPv6 for many of the same purposes as it is in IPv4.

Kensuke Fukuda and John Heidemann. 2018. Who Knocks at the IPv6 Door?: Detecting IPv6 Scanning. In Proceedings of the Internet Measurement Conference 2018 (IMC ’18). ACM, New York, NY, USA, 231-237. DOI: https://doi.org/10.1145/3278532.3278553

When should you use IPv6 PA space?

3 June 2019 |

I was reading RFC8475 this week, which describes some IPv6 multihoming ‘net connection solutions. This set me to thinking about when you should uses IPv6 PA space. To begin, it’s useful to review the concept of IPv6 PI and PA space. PI, or provider independent, space, is assigned by a regional routing registry to network…

IPv6 Security Considerations

31 January 2019 |

History of Networking: Bob Hinden on IPv6

13 November 2018 | Comments Off on History of Networking: Bob Hinden on IPv6

The State of IPv6 Deployment

10 October 2018 | Comments Off on The State of IPv6 Deployment

IPv6 Security Considerations

1 October 2018 | Comments Off on IPv6 Security Considerations

When rolling out a new protocol such as IPv6, it is useful to consider the changes to security posture, particularly the network’s attack surface. While protocol security discussions are widely available, there is often not “one place” where you can go to get information about potential attacks, references to research about those attacks, potential counters,…

SLAAC and DHCPv6

5 December 2017 |

When deploying IPv6, one of the fundamental questions the network engineer needs to ask is: DHCPv6, or SLAAC? As the argument between these two has reached almost political dimensions, perhaps a quick look at the positive and negative attributes of each solution are. Originally, the idea was that IPv6 addresses would be created using stateless…

On the ‘net: Fragmentation and IPv6

21 September 2017 | Comments Off on On the ‘net: Fragmentation and IPv6

Does this mean we ban all filtering of traffic on the public Internet, imposing the end-to-end rule in earnest, leaving all security to the end hosts? This does seem to be the flavor of the original IPv6 discussions around stateful packet filters. This does not, however, seem like the most realistic option available; the stronger…

The Back Door Feature Problem

4 January 2017 | Comments Off on The Back Door Feature Problem

In Don’t Forget to Lock the Back Door! A Characterization of IPv6 Network Security Policy, the authors ran an experiment that tested for open ports in IPv4 and IPv6 across a wide swath of the network. What they discovered was interesting— IPv6 is more open than IPv4. A given IPv6 port is nearly always more…

Scroll To Top