Nominum Foundation Authoritative Name Server (ANS) and Caching Name Server (CNS) are written-from-scratch DNS servers targeted specifically to carriers, providers, and now large Enterprise deployments. The products are offered as software, to be loaded on the customer's provided hardware running Linux (Red Hat Enterprise, SuSE) or FreeBSD on Intel processors; or Solaris/SPARC machines. At least 1 GB of RAM and 10 GB of disk space are recommended on the deployed hardware.

The vendor bills their software as especially designed for high-performance environments; providing performance graphics listing a maximum response time of 1 ms for ANS queries and the ability to process nearly 60,000 requests per second in CNS. In combination with other features, the additional headroom this performance affords--according to the vendor--makes the products especially resilient to Denial of Service attacks leveled against DNS servers.

An additional feature of both products is the ability to reload configuration data (including Zone configurations) without requiring a restart. Though Nominum's personnel roster includes engineers who worked on BIND, the vendor states that both ANS and CNS were written from scratch and do not share BIND code.

As its name implies, Nominum Foundation ANS is purpose-designed to serve only as an Authoritative Name Server with scalable support for "millions of names" and "millions of zones." In addition to the features described above, ANS supports template-based zone configuration and maintenance; configuration change and management statistics auditing and logging to support rollback or forensic needs; support for real-time configuration changes via CLI; support for split-DNS views; and support for IPv6 and DNSSEC. ANS can import and use existing BIND configuration files without requiring conversion.

CNS, on the other hand, is designed to serve only as a Caching Name Server; retrieving DNS responses from upstream Authoritative Servers, caching them and making them available for local queries. In addition to its performance, a key feature of CNS is its "Response Validation" technology, which examines all DNS packets and screens out those that are malformed or malicious before providing them to downstream requestors. Additionally, the vendor states that CNS operates only within predefined memory constraints regardless of the number of requests it receives.

Nominum Foundation ANS and CNS are available now. Visit the vendor's site for further information.