Where is qname

In the case of zones that contain labels that are multiple levels deep reverse PTR lookups for IPv6 is the classic example , QNAME minimization can require more queries than previously necessary.

This difference will diminish as the cache is primed with answers. BIND 9 caches and reuses negative responses to avoid superfluous queries.

QNAME minimization makes each negative answer more useful. The Pew Research Center has done extensive surveys on end-user attitudes towards their online privacy.

Unsurprisingly, they are finding consumer concern has increased substantially over the last few years. Some of this concern about social media and data sharing has already carried over into concern about DNS privacy. Multiple new DNS services that promise to protect end-user privacy have emerged in the past two years and are seeing tremendous adoption. Quad9 which operates a DNS resolver service at 9. Cloudflare, which operates 1. QNAME minimization is only one element in an overall privacy protection plan.

It does not encrypt your communications, nor does it ensure the integrity of data received. However, QNAME minimization is important to minimize passive data leakage, and it is one end-user privacy step that requires absolutely no effort or retraining of the end user. It is also easy for the service provider to deploy and does not add any cost or performance penalties. We are very proud to announce that we have just posted a new stable branch of Kea, Kea 2.

As the DNS operator for the. A resolver could therefore simply ask us for the name servers for example. The reasons for that are largely historical. Query name minimisation qmin , an IETF standard introduced in as see RFC , describes how recursive resolvers should limit the information revealed to the minimum.

So, in the example above, a resolver should query us only for example. While that sounds simple enough, the concept of qmin is a little more complicated in practice. The main reason is that delegations can exist at any level.

For example, a domain a. Consequently, qmin implementations theoretically have to query for the domain iteratively, increasing the length of the domain by one step each time, until a delegation is encountered.

Because the standard is more than two years old, and because some resolver software already has qmin implementations, we were curious to know how far qmin deployment has progressed on the Internet.

We detected qmin support by utilising the fact that a non-qmin resolver will miss any delegation that happens in one of the labels before the terminal label.

So, if we delegate to a different name server, with a different record for the terminal label in one of the labels before the terminal label, qmin resolvers will obtain a different answer from that obtained by non-qmin resolvers. We, therefore, scheduled a series of longitudinal measurements using the RIPE Atlas measurement network. We were able to detect a non-qmin resolver because such a resolver will send a query for the full qname to the authoritative name server for qnamemin-test.

A qmin resolver will send a query for just the second-to-last label, b. Figure 1 below shows the adoption of qmin since May In our study period, adoption grew from 0. Updated numbers are published daily here.

Figure 1: T he adoption of qmin since May First, we queried a list of 1. Out of those, only 1. We assume that a resolver supports qmin if it sends mostly queries for the two rightmost labels of a domain name example. You can find daily updated statistics on our statistics website stats.

Figure 1: T he adoption of qmin in the. This specific solution is not intended to fully solve the DNS privacy problem; instead, it should be viewed as one tool amongst many. In a conversation with the author in January , Paul Mockapetris explained that this tradition comes from a desire to optimise the number of requests, when the same name server is authoritative for many zones in a given name something that was more common in the old days, where the same name servers served.

Whatever the merits of this choice at this time, the DNS is quite different now. In the example in the previous section, sending "What are the NS records for. The rest of this section describes the recommended way to do QNAME minimisation -- the way that maximises privacy benefits other alternatives are discussed in the appendices. Let's assume that it already knows that ns1. The minimising resolver works perfectly when it knows the zone cut zone cuts are described in Section 6 of [RFC].

But zone cuts do not necessarily exist at every label boundary. If we take the name www. So, assuming that the resolver already knows the name servers of. To find the zone cut, it will query the. Appendix A describes this algorithm in deeper detail. Since the information about the zone cuts will be stored in the resolver's cache, the performance cost is probably reasonable. Section 6 discusses this performance discrepancy further. So, in theory, it should work without any problems. This behaviour is a protocol violation, and there is no need to stop improving the DNS because of such behaviour.

It breaks negative answers, since the servers don't return the correct SOA, and it also breaks anything dependent upon NS and SOA records existing at the top of the zone. Instead of querying name servers with a query "NS example. If ent. If a resolver queries only foobar. It works, but it is not ideal for privacy. We don't know why they don't do it. This lets them have many web-hosting customers without having to configure thousands of individual zones on their name servers.

They just tell the prospective customer to point their NS records at the hoster's name servers, and the web hoster doesn't have to provision anything in order to make the customer's domain resolve. Protocol and Compatibility Discussion QNAME minimisation is compatible with the current DNS system and therefore can easily be deployed; since it is a unilateral change to the resolver, it does not change the protocol.

Because it is a unilateral change, resolver implementers may do QNAME minimisation in slightly different ways; see the appendices for examples. One may notice that many documents that explain the DNS and that are intended for a wide audience incorrectly describe the resolution process as using QNAME minimisation e. As a result, these documents may confuse readers that use them for privacy analysis.