Building

IPv6 RA Flags, RDNSS and DHCPv6 Conflicting Configurations Revisited

Good morning dear readers,

as you may know, we published a whitepaper discussing the behavior of different operating systems once they receive IPv6 configuration parameters from different sources two years ago. At that time, the results were quite a mess. We were curious whether the situation is still so “dire” like two years ago. We fired up the lab, updated the tested operating systems and performed the tests again. Continue reading “IPv6 RA Flags, RDNSS and DHCPv6 Conflicting Configurations Revisited”

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Misc

One Step Closer – RDNSS (RFC 8106) Support in Windows 10 Creators Update

Good Afternoon,

It is a pleasant surprise for many (us included) that Microsoft implemented support for the RDNSS (RFC 8106) option in Router Advertisements beginning with the Windows 10 Creators Update. Interestingly, I wasn’t able to find any official documents from Microsoft stating this. As we are involved in a lot of IPv6 related projects for our customers, the lack of RDNSS support for Windows and DHCPv6 for Android is a major pain point when implementing IPv6 in mixed client segments, as you need to implement both mechanisms to ensure that all clients do get the relevant network parameters. I won’t beat on the dead horse, but Microsoft’s decision is a huge step in the right direction and one can hope that one day Google finds a “compelling use case” to implement at least stateless DHCPv6 for Android. Continue reading “One Step Closer – RDNSS (RFC 8106) Support in Windows 10 Creators Update”

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Breaking

Some Notes from the Lab – BlackNurse in the IPv6 Era

Since BlackNurse was released on 10th of November, we asked ourselves whether this problem does also apply to ICMPv6 traffic. To answer this question, Christian Tanck (one of our students) build a lab with several firewall appliances. Kudos to him for testing and the following blog post.

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Breaking

CVE-2016-1409 – IPv6 NDP DoS Vulnerability in Cisco Software

Dear readers,

As you may have already noticed, Cisco released an urgent security advisory describing an IPv6 Neighbor Discovery DoS Vulnerability in several flavors of Cisco’s operating systems. Currently IOS-XR, XE and NX-OS are affected while ASA and “classic” IOS are under investigation. At first glance, it might look like yet another IPv6 DoS vulnerability. Looking closer, Cisco is mentioning an unauthenticated, remote attacker due to insufficient processing logic for crafted IPv6 NDP packets that are sent to an affected device. Following the public discussion about the vulnerability, it seems that these packets will reach the, probably low rate-limited, LPTS filter/queue on IOS XR devices “crowding” out legitimate NDP packets resulting in a DoS for IPv6 traffic, or in general a high CPU load as these packets will be processed by the CPU. More details are currently not available, but this might indicate the affected systems aren’t doing proper message validation checks on NDP packets (in addition to the LPTS filter/queue problem).

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Events

Reflections on the IPv6-only WiFi Experience during Troopers

Hello,

Troopers is (unfortunately) over. It was a blast (but I may be biased ;-))! After things have settled, I want to take the opportunity to reflect my thoughts and impressions on the IPv6-only WiFi we had deployed during the conference. To make sure that everybody is on the same page let’s start at the beginning.

In the last couple of years we had provided Dual-Stack connectivity on the main “Troopers” SSID but also had an additional IPv6-only SSID. This year we decided to spice things up and made the “Troopers“ SSID IPv6-only (with NAT64) while providing Dual-Stack connectivity on the “Legacy“ SSID. We wanted to get a feeling how many clients and applications can work properly in an IPv6-only environment. We intentionally didn’t announce it vastly beforehand, hoping that attendees would just connect to the main SSID without noticing anything. We were aware that some applications might expose issues but, as I said , we wanted to get a feeling to which degree problems actually occured. Continue reading “Reflections on the IPv6-only WiFi Experience during Troopers”

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Events

Multicast Based IPv6 Neighbor Spoofing / Response Behavior on Cisco Devices

Dear readers,

today we want to examine the behavior of Cisco devices when they receive spoofed IPv6 Neighbor Advertisement packets from an untrusted system pretending to be the default router for the local segment. We start with a quick refresher how Cisco devices behave in the legacy (IPv4) world when they receive a spoofed broadcast ARP packet containing the IP address of the device but with a different MAC address, followed by a discussion of the corresponding behavior in the IPv6 world. Continue reading “Multicast Based IPv6 Neighbor Spoofing / Response Behavior on Cisco Devices”

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Events

Observations from the Cisco Live Europe 2016 Wifi Infrastructure

Good Evening,

Enno and I spent the first day on Cisco Live Europe in Berlin today attending the “Advanced Practical Knowledge for Enterprise Deploying IPv6” technical breakout held by Tim Martin and Jim Bailey. It was a good breakout session, and thanks again Tim for the honorable mention of our work in your slides! We really appreciate it. Like last year, we were curious how the Wifi network was setup this year as I face a corresponding task for Troopers in March, with some major changes in comparison to the last years. Continue reading “Observations from the Cisco Live Europe 2016 Wifi Infrastructure”

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Events

#TR16 IPv6 Security Summit Teaser: Basic IPv6 Attacks & Defenses Workshop

Dear Readers,

It’s me again with another teaser for an upcoming workshop at the IPv6 Security Summit. This one is a classic! If you happen to deploy IPv6 in your environment in the near future, but didn’t had the time to think about the security implications, this workshop is the right place to start. Continue reading “#TR16 IPv6 Security Summit Teaser: Basic IPv6 Attacks & Defenses Workshop”

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Events

Multiple Address Family OSPFv3

Dear Readers,

today I want to talk about OSPFv3. I won’t cover the glory details of OSPFv3, there are smarter guys than me out there who did that already 😉 and there are great resources to familiarize yourself with the protocol. However, it should be noted that OSPFv3 is not only OSPF for IPv6, OSPFv3 brought some major enhancements compared to OSPFv2. Wouldn’t it be cool to benefit from the enhancements in the IPv4 world as well? Continue reading “Multiple Address Family OSPFv3”

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Events

#TR16 IPv6 Security Summit Teaser: First-Hop-Security on HP Network Devices

Hello Everybody,

Today I want to give you a little teaser about my upcoming talk at the IPv6 Security Summit about First-Hop-Security on HP devices. In the past I presented on about First-Hop-Security in the Cisco realm and in virtualized environments. Until recently, Cisco was mostly the only vendor who had a sufficient implementation of various IPv6 security features on their access-layer switches, but HP closed the gap considerably and it’s time to have an in-depth look at their implementation of those features.

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