SQL Server connection issues

  • Article

After installing sql server 2012 along side of sql server 2008 R2, i was not able to connect to the new named instance of 2012. The following are the troubleshooting steps which led to the solution,

  1. check if the TCP net protocols ( go to the sql server configuration manager ) are enabled.
  2. The port number is not conflicting with the default port which is used by other instance. go to the properties of network protocol and check if the IP address and the port number mentioned are correct.
  3. open an inbound rule for the new TCP port in firewall settng.
  4. now restart the service and check if the new instance can be connected locally and remotely.
  5. if it is not possible to connect from remote machine, try to connect as <servername>,<port number>. if this works then the port is properly assigned, otherwise there is some conflict of the port mentioned. if so, check what are the ports mapped on the server. This can be identified by executing netstat -ao from command prompt.
  6. if it is not possible to connect as <server name>\<instance name> then check if SQL Browser service is running. if not start that service and try to connect.