Joris Evers has this alarming piece today "Will Vista stall net traffic?" Just to clarify, the story was talking about the potential of Windows Vista to double DNS traffic and possibly overload existing DNS servers. Paul Mockapetris raised an alarm on a possible DNS meltdown last month but is now sounding off again pointing to Windows Vista as the culprit. Mockapetris is credited with the invention of DNS and currently works for Nominum which is in the business of selling high-performance DNS appliances. Evers cited Mockapetris along with other experts and Microsoft who disagreed with Mockapetris' doomsday assessment, but is there really anything to worry about?
I had the honor of meeting Paul Mockapetris in May of last year at Interop 2005 and he enlightened me on some DNS issues. This was soon after the series of DNS outages at Comcast last year so the possibility of DNS overloading for large Internet Service Providers is real but this latest alarm on Windows Vista is not. Windows Vista will potentially double the number of DNS requests because it will query for an IPv4 address and an IPv6 address, but this is extremely unlikely because it only applies to Vista computers running in an IPv6 environment and this applies to any other operating system.
The reality is that hardly anyone outside of a few special research environments use IPv6 for their LAN infrastructure and you probably won't find a single fortune 500 company using IPv6 in their corporate LAN environment. IPv6 isn't even on the radar as far as IT planning is concerned because no one has ever made a compelling business case for the costly conversion. The likelihood that there will be a massive number of DNS request coming from IPv6 enabled Vista machines or any other IPv6 enabled operating system like Linux or OS X is simply out of the question. There will be no Vista-induced DNS meltdown. If IPv6 ever does become a reality, network architects will simply need to beef up their DNS infrastructure to accommodate both IPv4 and IPv6 requests.