2003 server single domain. All has been configured and working properly for many, many months. This afternoon, we all of the sudden lost the ability to resolve external names. Internal IPs no problem. Checked error logs for system and DNS on server - nothing, absolutely nothing. Checked for SOA and reverse lookup records - present. Stopped and restart services - event log says everything fine. But we cannot resolve outside names. Now down for two hours. Tried to read MS troubleshooting knowledgebase using our external wireless but nothing obvious. Really starting to pull me hair out. All suggestions welcome, logical, in order, and hopefully include a sure-fire "if all else fails try this" would be great.