Sql-server – SQL Server Linked Server – Timeout Error

Every machine in the chain from your desktop to the server you are calling has to be Kerberos enabled for the trust to advance past the first hop. So, yes the server needs to trust the user for delegation.

The "Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'" almost always indicates a delegation problem.

• Your Windows Account must have access to both ServerA and ServerB.
• You must not have the setting "Account is sensitive and cannot be delegated."
• Both ServerA and ServerB must have their own SPN registered.
• The servers must be TCP/IP or named pipes connected.

The SQL Server Books Online article that offers some more detail is "Configuring Linked Servers for Delegation": http://msdn.microsoft.com/en-us/library/ms189580(v=sql.105).aspx

From BOL:

Be made using the login's current security context

Specify that a connection will be made using the current security context of the login for logins not defined in the list. If connected to the local server using Windows Authentication, your windows credentials will be used to connect to the remote server. If connected to the local server using SQL Server Authentication, login name and password will be used to connect to the remote server. In this case a login with the exact same name and password must exist on the remote server.

http://technet.microsoft.com/en-us/library/ms188477(v=sql.105).aspx

Using the login's current security context will use whatever user is logged in to the local machine. Be it Windows authentication or SQL authentication.

So, in your example above, if JOEsmith logs into server A and runs a query against server B, it will execute the query on server B using JOEsmith, as long as JOEsmith is a valid logon for server B.