您正在使用的MSSQL实例名称是什么?

What is MSSQL instance name you are using?

如果您未指定实例名称并像"server.com"那样进行连接，则使用默认实例名称"MSSQLSERVER"，但是您的MSSQL服务器的实例名称可能是"MSSQLSERVER2012"或"SQLEXPRESS"，在这种情况下，您可以应该像"server.com \ MSSQLSERVER2012"或"server.com \ SQLEXPRESS"那样连接

If you don't specify instance name and connect like "server.com" than default instance name is used "MSSQLSERVER", but instance name of your MSSQL server may be "MSSQLSERVER2012" or "SQLEXPRESS" and in this case you should connect like "server.com\MSSQLSERVER2012" or "server.com\SQLEXPRESS"

您可以在"SQL Server配置管理器"中检查实例名称:

You can check instance name in "SQL server configuration manager":

如果实例名称正确，请检查指定IP地址的远程网络连接是否已启用"(但要注意安全威胁):

In case instance name is OK, check that remote network connections are "Enabled" for specified IP addresses(but pay attention to security threats):

安全说明

当您允许与MS SQL Server的远程连接时，这意味着SQL Server 将打开以接受密码暴力攻击，拒绝服务(DoS)攻击以及任何种类的利用攻击.

When you allow remote connections to MS SQL server it means that SQL server will be open for password brute force attacks, Denied of Service(DoS) attacks, any kinds of exploit attacks.

所有这些攻击都可能使整个服务器变慢.

All this kinds of attacks may slowdown whole your server.