Do we need multiple port to be open if more than 2 instance are installed on SQL Server
Hi , I have litte Query about the PORT in SQL Server. As all we know 1433 is default port for SQL Server. Suppose if we have 4 SQL Instance installed on the Window box name A, B, C,D. Do we need to enable the PORT seperatly or if i add 1433 port in cofiguration manager for any of the Instance. Will it allow to connect other instance by same port.... As i have add port 1433 on A instance so i am able to connect the instace A,1433 But when i try to connect B,1433 it didnot allow to connect.. Please let me know wheather i need to enable other port. Thanks Basit Khan
Each one of the Instances will use a different port (a default instance will use 1433). The SQL browser service listens on UDP 1434 and redirects you to the appropriate port when you connect to a named instance. The named instances will listen on random ports and so you will need to open up a broad range of addresses. You can avoid this by hard setting the port for each instance so that it is not dynamic (each instance will need to use a different port). In doing this you can either connect with the instance name (which will use UDP1434 and TCP) or you can just specify when connecting. For information on how to set the TCP/IP port for a SQL Server instance please check this books online article
The SQL Server Browser Service is what controls the traffic to each instance - the instance 'A' on your server is probably the default one. What port is used, is set dynamically - you will find which port it is by looking at the instance in Configuration Manager. If you restart the instance, it could change the port number so don't use the port number in any connection - use the instance name.