Latest posts.

Do you have a question for Mr. DNS?

If you have a question about DNS for Mr. DNS, he’d love to hear it. Drop him a line at

Episode 42

In Episode 42, we discuss the meaning of life, the universe and everything with a very special guest, @dnsreactions, creator of the hit DNS Reactions Tumblr.  “DR”, as we call him or her (or it?), prefers to stay anonymous, so we have obscured his/her/its voice using the magic of technology.  Our long-suffering listeners submitted questions for DR, who was very accommodating.  Enjoy!


Episode 41

Welcome to our special Halloween episode!  Okay, not really, but we are recording in late October…  This time we answer a record-breaking three questions from the same listener, Grant Taylor, who single-handedly supplied the material for all our tangents in this show.  We remind everyone of the dangers of cache poisoning in a discussion about CNAMEs, we strain our memories back to the early days of DNSSEC to discuss SIG(0), and we explain and opine on EDNS Client Subnet, a recent and increasingly popular DNS protocol extension.  Considering the time of year, we also lapse into a discussion of candy, specifically peanut M&Ms.


Episode 40

In this 40th episode–a milestone!–Matt and Cricket answer long-suffering listener Grant Taylor’s question about sorting replies by type and wander into the Land of Happy Eyeballs, then explore an answer Joe Abley received from Mark Andrews of ISC.  Meanwhile, a discussion of the term G-job causes Matt to recount accidentally insulting a group of public servants, and both Matt and Cricket discuss their hope that the new AppleTV will lead to the end of their paying for streaming content they could have watched for free.


Episode 39

In this star-studded episode, Matt and Cricket take advantage of a meeting of the DNS Cabal–that is, the annual “Inside Baseball” event–to answer Donald Rudder’s question about whether synthesizing NXDOMAIN responses to avoid random subdomain attacks would work with NSEC3 as well as NSEC records.  This is followed by a wildly entertaining (by DNS standards, anyway) discussion of the future of DNS, new TLDs, communication in the event of attacks, and more.

Guest-starring some of the brightest lights in DNS, including Kris Beevers, Brian Brady, David Dagon, Casey Deccio, Rob Fleischman, Olafur Gudmundsson, Shumon Huque, David “Tale” Lawrence, and Duane Wessels.


Episode 38

In this episode, long-time (and likely now sole) listener Yiorgos Adamopoulos asks about the the process of signing the root zone, which Mr. DNS has some experience with.  Matt also recaps some of the goings-on at the latest DNS-OARC meeting in Amsterdam, omitting that which must stay in Amsterdam, but revealing some lapses from his DNSSEC RFC-editing days.


Episode 37

Back after a long absence they try to avoid talking about, Cricket and Matt tackle some meat-and-potatoes questions: Why can’t one have a CNAME with other records at a domain name? Are registrars buying up expired domain names? How can one make a name server generate answers dynamically?  Listen as Matt embarrasses himself by forgetting the name of the Registry-Registrar Protocol (RRP), the predecessor to the Extensible Provisioning Protocol (EPP), used today between registrars and registries.  Cricket’s memory is working fine, though, as he dredges up a reference to lbnamed, a simple, Perl-based name server now remembered only by Google and DNS geeks.  And as usual, there are tangents: the episode winds up with an impromptu discussion of standing desks and how Matt is an effective but not-at-all-subtle choral conductor.


Episode 36

In this episode, Matt and Cricket respond to Tommi Nikkilä’s followup to his original question about the legality of multiple CNAME records in a DNS answer, and then react to (to claim they “answer” it is a reach) dedicated listener Yiorgos Adamopoulos’s question about registering domain names with underscores in them.  On the way, Matt describes his quest to set a personal record in his commute from his home in Bethesda to Dyn’s headquarters in Manchester, New Hampshire, and then (inadvertently?) disses Cricket’s manhood by suggesting that Real Men Drive with Standard Transmissions.  Finally, the guys bemoan their lack of questions, implying that this is somehow responsible for their sporadic production, when we know in fact it’s their own damn fault.


Episode 35

In this episode, Matt and Cricket wonder aloud whether they’ve lost their domestic audience, but then rally to answer questions from their remaining international listeners:  Evaggelos Balaskas’s question about SRV records, Joe’s questions about resolver and name server fallback to TCP, and Tommi Nikkilä’s question about multiple CNAME records attached to the same domain name.  And, oddly enough, they wrap up with a discussion of the joy of milk delivery.


Episode 34

In this episode, Matt and Cricket answer Harry Stein’s question about a DNSstuff search that turned up suspected cache poisoning, and Kirk Davis’s question about Google’s (somewhat crazy) recommendations on how to force the use their non-SSL-based services.


Episode 33

Here, at long last, is Episode 33, in which Matt announces a “Development with a capital D” (and a lowercase “yn”), and Matt and Cricket answer questions from Jason Weber about how to deal with web hosting and a hosted DNS zone; from Chuck Nelis about split DNS; from Michael Simoni about the (waning?) need for multiple zones; and from Matt Pounsett about the dangers of mixing recursion and authority on a single name server.