Improving DNS Performance Using "Stateless" TCP in FreeBSD 9
The introduction of DNSSEC and the increasing adoption of IPv6 will tend to generate DNS responses too large for standard DNS-over-UDP transport. This will create pressure for clients to switch to TCP for DNS queries, leading to a significant increase in overhead for DNS servers. Huston has proposed a "Stateless" version of TCP to reduce the server-side load on DNS servers handling DNS queries over TCP. Stateless TCP observes that typical DNS-over-TCP queries may be adequately handled by a simplified TCP connection establishment that reduces the kernel state required per connection.