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DNS Namespace Collisions: Detection and Response [Guest Post]

Jeff Schmidt, November 28, 2013, 11:39:56 (UTC), Domain Tech

Those tracking the namespace collision issue in Buenos Aries heard a lot regarding the potential response scenarios and capabilities. Because this is an important, deep, and potentially controversial topic, we wanted to get some ideas out early on potential solutions to start the conversation.

Since risk can almost never be driven to zero, a comprehensive approach to risk management contains some level of a priori risk mitigation combined with investment in detection and response capabilities.

In my city of Chicago, we tend to be particularly sensitive about fires. In Chicago, like in most cities, we have a priori protection in the form of building codes, detection in the form of smoke/fire alarms, and response in the form of 9-1-1, sprinklers, and the very capable Chicago Fire Department.

Let’s think a little about what the detection and response capabilities might look like for DNS namespace collisions.

Detection: How do we know there is a problem?

Rapid detection and diagnosis of problems helps to both reduce damage and reduce the time to recovery. Physical security practitioners invest considerably in detection, typically in the form of guards and sensors.

Most meteorological events are detected (with some advance warning) through the use of radars and predictive modeling. Information security practitioners are notoriously light with respect to systematic detection, but we’re getting better!

If there are problematic DNS namespace collisions, the initial symptoms will almost certainly appear through various IT support mechanisms, namely corporate IT departments and the support channels offered by hardware/software/service vendors and Internet Service Providers.

When presented with a new and non-obvious problem, professional and non-professional IT practitioners alike will turn to Internet search engines for answers. This suggests that a good detection/response investment would be to “seed” support vendors/fora with information/documentation about this issue in advance and in a way that will surface when IT folks begin troubleshooting.

We collectively refer to such documentation as “self-help” information. ICANN has already begun developing documentation designed to assist IT support professionals with namespace-related issues.

In the same way that radar gives us some idea where a meteorological storm might hit, we can make reasonable predictions about where issues related to DNS namespace collisions are most likely to first appear.

While problems could appear anywhere, we believe it is most likely that scenarios involving remote (“road warrior”) use cases, branch offices/locations, and Virtual Private Networks are the best places to focus advance preparation.

This educated guess is based on the observation that DNS configurations in these use cases are often brittle due to complexities associated with dynamic and/or location-dependent parameters. Issues may also appear in Small and Medium-sized Enterprises (SMEs) with limited IT sophistication.

This suggests that proactively reaching out to vendors and support mechanisms with a footprint in those areas would also be a wise investment.

Response: Options, Roles, and Responsibilities

In the vast majority of expected cases, the IT professional “detectors” will also be the “responders” and the issue will be resolved without involving other parties. However, let’s consider the situations where other parties may be expected to have a role in response.

For the sake of this discussion, let’s assume that an Internet user is experiencing a problem related to a DNS namespace collision. I use the term “Internet user” broadly as any “consumer” of the global Internet DNS.

At this point in the thought experiment, let’s disregard the severity of the problem. The affected party (or parties) will likely exercise the full range of typical IT support options available to them – vendors, professional support, IT savvy friends and family, and Internet search.

If any of these support vectors are aware of ICANN, they may choose to contact ICANN at any point. Let’s further assume the affected party is unable and/or unwilling to correct the technical problem themselves and ICANN is contacted – directly or indirectly.

There is a critical fork in the road here: Is the expectation that ICANN provide technical “self-help” information or that ICANN will go further and “do something” to technically remedy the issue for the user? The scope of both paths needs substantial consideration.

For the rest of this blog, I want to focus on the various “do something” options. I see a few options; they aren’t mutually exclusive (one could imagine an escalation through these and potentially other options). The options are enumerated for discussion only and order is not meaningful.

  • Option 1: ICANN provides technical support above and beyond “self-help” information to the impacted parties directly, including the provision of services/experts. Stated differently, ICANN becomes an extension of the impacted party’s IT support structure and provides customized/specific troubleshooting and assistance.
  • Option 2: The Registry provides technical support above and beyond “self-help” information to the impacted parties directly, including the provision of services/experts. Stated differently, the Registry becomes an extension of the impacted party’s IT support structure and provides customized/specific troubleshooting and assistance.
  • Option 3: ICANN forwards the issue to the Registry with a specific request to remedy. In this option, assuming all attempts to provide “self-help” are not successful, ICANN would request that the Registry make changes to their zone to technically remedy the issue. This could include temporary or permanent removal of second level names and/or other technical measures that constitute a “registry-level rollback” to a “last known good” configuration.
  • Option 4: ICANN initiates a “root-level rollback” procedure to revert the state of the root zone to a “last known good” configuration, thus (presumably) de-delegating the impacted TLD. In this case, ICANN would attempt – on an emergency basis – to revert the root zone to a state that is not causing harm to the impacted party/parties. Root-level rollback is an impactful and potentially controversial topic and will be the subject of a follow-up blog.

One could imagine all sorts of variations on these options, but I think these are the basic high-level degrees of freedom. We note that ICANN’s New gTLD Collision Occurrence Management Plan and SAC062 contemplate some of these options in a broad sense.

Some key considerations:

  • In the broader sense, what are the appropriate roles and responsibilities for all parties?
  • What are the likely sources to receive complaints when a collision has a deleterious effect?
  • What might the Service Level Agreements look like in the above options? How are they monitored and enforced?
  • How do we avoid the “cure is worse than the disease” problem – limiting the harm without increasing risk of creating new harms and unintended consequences?
  • How do we craft the triggering criteria for each of the above options?
  • How are the “last known good” configurations determined quickly, deterministically, and with low risk?
  • Do we give equal consideration to actors that are following the technical standards vs. those depending on technical happenstance for proper functionality?
  • Are there other options we’re missing?

On Severity of the Harm

Obviously, the severity of the harm can’t be ignored. Short of situations where there is a clear and present danger of bodily harm, severity will almost certainly be measured economically and from multiple points of view. Any party expected to “do something” will be forced to choose between two or more economically motivated actors: users, Registrants, Registrars, and/or Registries experiencing harm.

We must also consider that just as there may be users negatively impacted by new DNS behavior, there may also be users that are depending on the new DNS behavior. A fair and deterministic way to factor severity into the response equation is needed, and the mechanism must be compatible with emergency invocation and the need for rapid action.

Request for Feedback

There is a lot here, which is why we’ve published this early in the process. We eagerly await your ideas, feedback, pushback, corrections, and augmentations.

This is a guest post written by Jeff Schmidt, CEO of JAS Global Advisors LLC. JAS is currently authoring a “Name Collision Occurrence Management Framework” for the new gTLD program under contract with ICANN.

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Comments (1)

  1. Also: Should registry operators that elected the alternate path to delegation are able to identify the source of the occurrence of a blocked string and can confirm that the potential collision has been removed be permitted to unblock such strings, and if so, what should be the process for that?

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