The Security Skeptic has published a blog post about using different ways to monitor DNS traffic for security threats. Using already existing systems like Firewalls, Intrusion detection systems, Traffic analyzers, Passive DNS replication and by turning on logging at your resolver you can increase the visibility in your network.
Read the full article over at http://www.securityskeptic.com/2015/02/5-ways-to-monitor-dns-traffic-for-security-threats.html.