A bit scary, but seems to have worked. One problem I had was that I had earlier added a firewall rule that was supposed to eliminate use of other DNS servers. Well, that rule seemed to have caused *NO* DNS queries to be successful after this change. Oops. Once I removed it, DNS started working again. I'll have to look into a somewhat different rule to either disallow outbound DNS queries from any IP other than my DNS, or disallow DNS to any external IP other than OpenDNS.