2023-06-01: This service has been deprecated in favor of Check My DNS. The announcement in Jul 2008 of CERT VU#800113 made it clear that resolvers should use random source source ports when sending queries. Here at OARC, we crafted a special DNS name and server that you can query to learn whether or not your own resolver is using random ports. Use a DNS query tool such as dig to ask for the TXT re