间歇性连接数据库失败, 先试试下面两篇文章

SQL Server Intermittent Connectivity Issue

http://blogs.msdn.com/b/sqlprogrammability/archive/2008/05/27/sql-server-intermittent-connectivity-issue.aspx

(provider: TCP Provider, error: 0 - Only one usage of each socket address (protocol/network address/port) is normally permitted.)

http://blogs.msdn.com/b/spike/archive/2008/08/26/provider-tcp-provider-error-0-only-one-usage-of-each-socket-address-protocol-network-address-port-is-normally-permitted.aspx