npgsql trouble in c# app - An existing connection was forcibly closed by the remote host

c#, npgsql, postgresql

Solution

I had spent 1 hour searching same and found no issues. But then realized that PG puts its logs in pg_log folder. I looked in it to see possible issue.

It turn out you just need to have correct "host" entry in "pg_hba.conf" file. For me this file is in C:\Program Files\PostgreSQL\9.1\data directory. For example

host all all 192.168.1.2/32 md5

Where 192.168.1.2 - is your client's ip address.

BTW, you still need to have 5432 port open as Inboud rule (windows Vista, Windows 7, Windows 2008+).

Problem

I am getting the following error when trying to open my Postgresql database from a C# utility: System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host I have tried running this program from a remote computer and from the computer on which the Postgresql server is running. There are no firewalls on either computer at this moment and I am able to connect to the database and server just fine through the postgres admin utility using the same password. I have checked that the username has permissions to the database. Here is my code for the connection: ``` public bool updateFromServer() { try { NpgsqlConnection conn = new NpgsqlConnection(connString); conn.Open(); conn.Close(); return true; } catch (Exception e) { conn.close() return false; } } ``` Any help with this would be appreciated.

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