I have a SQL Server with both TCP\IP and Named Pipes protocols enabled and configured.

From the server itself I can connect to the database using either TCP or Named Pipes, by specifying the connection as np:servername\instance

However from another server I can only connect using TCP\IP using servername\instancename. Adding the np: prefix just causes a connection timeout failure.

Do I need to open any specific ports in order to use Named Pipes? This is a named instance running on a dynamic port. The dynamic port is opened in the firewall.

The reason I'm looking into this is because I'm experiencing intermittent issues with an ODBC connection - timeouts, connection dropouts etc. From what I've read these issues have in the past been resolved by enabling Named Pipes - which I've done, but then by default my connections are using TCP, and by force, I can't get it to connect from this server.

  • Is your browser running and did you change the default name of the pipe? Apr 28, 2017 at 11:26
  • @SqlWorldWide - Yes browser is running, and No, it's the default name.
    – Molenpad
    Apr 28, 2017 at 12:08
  • is udp 1434 open for the browser to use?
    – Ste Bov
    Apr 28, 2017 at 13:33
  • @SteBov Yes it is. I can connect to the named instance with servername\instance name and can talk to UDP 1434 using PortQry
    – Molenpad
    Apr 28, 2017 at 13:44
  • Did you google named pipes port number? I did and it's 445. I don't know if it will improve your connectivity issues though.
    – Nick.Mc
    May 13, 2017 at 3:11

1 Answer 1


We had the same issue with legacy applications built around 1998-2007 when we ported SQL Server to a VLAN--for security purposes. Depending on which server we connected to we'd get spurious results--one would work and the other would not...because of a tighter VLAN configuration.

Our solution was to "bag" named pipes and to force TCP--as shown below. The SQL server port is denoted by XXXXX. This forced our legacy apps to use TCP no matter what. So far, it's fixed all our issues.


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