i have a windows server 2008 set up as a database server, i used to have MS SQL 2005 installed on it, due to some client changes i installed SQL 2008 R2 along with the 2005, the R2 is with a named instance. when i tried to connect an application to the 2008 R2 database, i get:
network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: TCP
Provider, error: 0 - A connection attempt failed because the connected
party did not properly respond after a period of time, or established
connection failed because connected host has failed to respond.)
i am sure of the ports as i checked the named instance configuration on the DB server, i also telnet the dynamic IP from the application server and it is going through. i also tried to connect a copy of the application from a demo server i have with the same configuration as the application server and it was successful. from the application server it is not, any suggestions?
Copyright Notice：Content Author:「Mohammad Alsukar」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/29964232/connection-to-sql-2008-r2