Linked server queries fail with below error
Login failed for user ‘NT AUTHORITY\ANONYMOUS LOGON’. (Microsoft SQL Server, Error: 18456)
Above error occurs when the kerberos authentication fails in SQL Server you can follow the simple steps below to fix the Kerberos authentication failures. More detailed troubleshooting steps for Kerberos authentication failure is documented in http://mssqlwiki.com/2013/12/09/sql-server-connectivity-kerberos-authentication-and-sql-server-spn-service-principal-name-for-sql-server/
If the startup account/ User Account is in a Windows Server 2003 functional level domain, in active directory users and computers Right-click Startup account, and then click Propertiesclick the Delegation tab. select Trust this user for delegation to any service (Kerberos only).
If the startup account/User account is in a Windows Server 2000 functional level domain, in active directory users and computers Right-click Startup account, and then click , In the Account options box, confirm that Account is sensitive and cannot be delegated is not selected.
Make sure SPN’s are registered for all the SQL Server instances.
Make sure login accounts have read and write SPN permissions. You can also workaround the issue by creating named pipe alias on source server to destination server. More details in Kerberos Authentication in SQLServer