In my presentations and consultations on Web performance, I emphasize the importance of a correctly configured DNS system with the phrase: "If people can't resolve your hostname, your site is dead in the water".
Yesterday, it appears that the large anti-virus and security firm Sophos discovered this lesson the hard way.
Of course hindsight is perfect, so I won't dwell for too long on this single incident. The lesson to be learned here is that DNS is complex and critical, yet is sometimes overlooked when considered the core issues of Web performance and end-user experience.
This complexity means that if an organization is not comfortable managing their own DNS, or want to broaden and deepen their DNS infrastructure, there are a large number of firms who will assist with this process. These firms whose entire business is based on managing large-scale DNS implementations for organizations.
DNS is critical. Never take it for granted.