Issue with SQL Server Aliases on a multi-instance installation I've a 64-bit installation of SQL 2008 R2 SP2 on Server 2008 R2, with five instances of SQL.

I can get the aliases set up to work fine on the server (i.e. if I remote onto the server, then it works without problems, but from the client machine, there is no joy).

Errors:

SQL Pipes Error 40, Error 53. 

Or, if specify port 1433, TCP Error 0, 11004. 

If I specify port 63769 (which is mentioned as a port that SQL is listening on), TCP Error 0, 11004.

If I connect using the servername\instancename I have no problems.

I've set up the alias in 32-bit and 64-bit on the server. I've left the ports as dynamic in the TCP settings, because if I define the port as being 1433 for each instance, none of them will start. This is weird, as it's an approach I've used successfully on other servers.

There is no internal firewall, but some ports may, or may not, be shut off...

Any ideas about what to try next?

Thanks!
If you want aliases to work from the client then you have to create them on the client. Install the SQL Server client (from memory the feature is called Client Tools) and use Configuration Manager to create the aliases (32-bit or 64-bit to match the client application).