I wanted to make a ODBC connection from Windows PC to AS/400 DB2 server and I wrote a VBA program. But I got the following error.
Remote port could not be resolved
Then, I checked the status of server with CWSPING and got the result below:
I - Verifying connection to system 192.168.1.2...
I - Successfully connected to server application: Central Client
I - Successfully connected to server application: Network File
I - Successfully connected to server application: Network Print
I - Successfully connected to server application: Data Access
I - Successfully connected to server application: Data Queues
I - Successfully connected to server application: Remote Command
I - Successfully connected to server application: Security
E - CWBCO1011 - Remote port could not be resolved
E - CWBCO1008 - Unable to connect to server application DDM, returned 8407
I - Successfully connected to server application: Telnet
W - CWBCO1015 - Connection verified to system 192.168.1.2, but there were warnings
This means DDM service is not working on the server. ODBC connection requires DRDA, which runs upon DDM service, so I think running DDM service is the key to make ODBC connection. So I tried STRTCPSVR *DDM command but got the result below
*DDM not valid for parameter SERVER
And also tried CHGDDMTCPA AUTOSTART(*YES) PWDRQD(*YES) command, but got an error and I got stuck.
Command CHGDDMTCPA in library *LIBL not found
Does anyone have an idea of enabling DDM server on AS400?
Server: IBM AS400
OS version: V4R1
Try STRHOSTSVR *DATABASE.
STRHOSTSVR is used to start servers associated with IBM i Access and i Access Client Solutions.
STRTCPSVR is used, in general, to start servers associated with TCP/IP like FTP, Telnet, etc. Except the HTTP Server which is started via the Web Administration site at http://<server>:2001.
Additionally to the answer from #jmarkmurphy:
You can easily check netstat *cnn for open ports.
There is actually a tcpsvr named *ddm but that isn't used with ODBC.
ODBC-Access only needs host server *database. There aren't any further requirements for host servers.
For checking which services are started at tcp startup time, use strfdu, option 5 with the file qusrsys/qatocstart. From there you can easily view and change what should be started and what not.
Finally, I got connected by using JDBC. The summary of what I found is as follows:
ODBC seems using DRDA(port 446) but the server does not have DRDA/DDM service
OLEDB seems connecting Data Access(port 8471) but issued unknown error
JDBC also connection Data Access(port 8471) and it worked!
The first error I encountered when using ODBC is "Remote port could not be resolved". What happened behind this seems as follows:
ODBC asked Server Mapper(port 449) to find DRDA port(it may change on a server)
Server Mapper could not find DRDA port because the server has no DRDA service
ODBC showed "port not resolved" error
Then, I tried OLEDB this time. It checked user/password correctly but issued unknown error. When I put incorrect password, it showed "password is incorrect", which means OLEDB successfully log on to the server but got some error after sign on.
The last, I used JDBC and successfully connected! Generally, the connection url is like "jdbc:as400://" but it showed error. Using trace of JDBC, it seems to have problem on sign on to the server. So I changed the url to "jdbc:as400://:8471", then I finally connected. Looking into trace, it directly access to port 8741 and send user/password and get connected. I don't know the detail, but it worked!
Appreciated for your help!
Related
While trying to connect to SQLAnywhere (Sybase) database (C# code) from Azure ServiceFabric:
await using var connection = new SAConnection(connectionString);
await connection.OpenAsync();
receive iAnywhere.Data.SQLAnywhere.SAException
Connection error: Connection was dropped (may not be a SQL Anywhere server)
Error code is Error 832. This is generic connection error: An error occurred while attempting to establish a connection with the database server, but before attempting to connect to a database. Failure to initialize a communication link during the connection attempt is an example of this error. Creating a debug log file using the LogFile connection parameter may provide more information.
Locally it works, but does not work from Service Fabric.
Fix ideas tried:
Missing driver? Looks like no, Sybase (now SAP) SQLAnywhere requires special driver or client - but locally also works without this driver, just with iAnywhere.Data.SQLAnywhere.NETCore nupackage installed
Network connection/ firewall problems? Looks like no, database server can be pinged from Service Fabric node
It was another traffic protection tool. Although it was possible to telnet the port, still traffic from app was blocked by another tool.
Had a similar issue - turned out that whilst standard incoming traffic from the Sybase Server had been whitelisted in our Firewall, encrypted traffic from this had not been.
This meant I could ping and connect with Telnet, but got the same error when trying to log-in with my credentials
Connection error: Connection was dropped (may not be a SQL Anywhere server)
Our comms team solved the issue by whitelisted encrypted traffic from the server address as well. They also mentioned it possibly could have been solved we shared a valid security certificate for the encrypted data with their team, but were happy with the first course of action.
We have oracle oledb connections in SSIS packages that are working well on windows server 2008.
We moved them to windows server 2012 and installed the needed softwares. We installed oracle client (oraoledb driver), moved tnsnames.ora, ldap.ora and sqlnet.ora to %Oracle_Home%\Network\admin path, add %Oracle_Home% and %Oracle_Home%\bin to path variable.
But on server 2012 oracle connections are giving this error ORA-12541: TNS: no listener. Where as on server 2008 same oracle connections are working fine.
Looked so much across internet but found these solutions:
Check tnsnames.ora
Check listener is running
Check path variable contain oracle home, oracle_home\bin
I don't see a problem with tnsnames.ora because same file is present on both window servers. Correct path variables are also set. Listener is also running (since SSIS on server 2008 is connecting). And I am able to ping oracle db server from both machines.
Can anyone suggest anything that we may try.
To put a formal answer in here.
Basic troubleshooting steps with SSIS:
Use the database native tools to check connectivity
In this case for Oracle that is SQLPLUS.EXE
If you have an issue with native tools then it isn't an SSIS issue
Check that you can resolve the host by using PING <hostname>.
If that doesn't work try PING <ip address>
If ping works, check the port with TELNET <host> <port>
If that doesn't work, either the service is not listening or you need to get your network guys to open the port
This goes for any network service
i.e.
SQL Server (default port 1433)
a web server (default port 80 for unencrypted comms)
I got 2 servers with two equal wcf services hosted on them and one client application server. I can connect to endpoints and send a requests to both services using test wcf client app (.NET Web Service Studio) from my local machine successfully. But when I am trying to connect from client application server using the same test wcf client app I successfully connected only to the one wcf service server, but I have got an error when connecting to another one:
System.Net.WebException: There was an error downloading 'https://XXX/XXX?wsdl'. ---> System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it XX.XXX.XX.XXX:443
I performed netstat -an | find "443" command in command prompt on the client server and on my local machine to find out the difference and here what I have got:
1. On my local machine:
2. On the client app server:
What I already tried to do on client application server is:
- turned off firewall;
- stopped windows firewall service
- uninstalled mcafee virusscan enterprise application.
(I tried to set "prevent mass mailing worms from send mail" first, but mcafee was in foreign language that I don't understand, so I just uninstalled it)
after running command netstat -aon | findstr "443" on client application server I have got this result:
but I still got an error.
Does anybody know how to solve this issue?
Could be the problem on the wcf service server side?
The solution was predictable simple one - firewall was blocking the port,
but it's important to notice that the issue was caused by firewall on the wcf service server side, but not on client application server, which is making the request to that service.
I asked the technical support of that server, and they made firewall changes.
After that error was disappeared.
I faced the same issue and tried different ways to fix this. Nothing works. Later i found the issue which is, the application i tried to run is https and in my IIS, https binding was not created. I created binding https with the website and it works.
I was wondering if there is a way to see if a server blocks outgoing connections. I am trying to connect to an external database from a client's server.
This is the error I get:
A 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.)
Edit:
I forgot to say I only have access to the plesk control panel. That's why I was asking if there is a way with asp.net.
When you say "server", do you mean the asp.net server, or the SQL server? And are both machines on the same network? Is this hosted?
Sql Server:
They can remove the OPENROWSET functionality, so you can't connect to remote servers, regardless
I doubt they are giving you access to linked servers in a hosted env
ASP.Net
You can try to connect to the other server via a regular connection, and see if that works.
Download a tracert component, and use that to try to trace from your server to the remote one.
If it dies somewhere inside your network, then that is your answer (it is blocked)
If it works, the outbound is open. Doesn't mean 1433 is open though.
If it dies after, not blocked, but maybe the remote is blocking icmp echo
Remember to try to tracert to somewhere else that you know works
It will be hard to tell what is killing the connection on 1433, if you can get to the server using other means. Could be the firewall, their fw, etc.
The trusty telnet method:
telnet theserver 1433
If this times out, the server is not listening. If the screen blanks and you can type something, the server is listening and no firewall is blocking the connection.
In Vista and Windows 7, you have to install telnet as a Windows component from Control Panel -> Programs and Features.
I have a login page that works in my local development environment. When I push the site onto the web server, i am getting this error when trying to login from the asp.net login control.
An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I cannot figure out why it does not work on the server. Do I need to add anything or change something in the web.config?
This support article may help. It may also be a firewall issue or an authentication issue on the new setup (but the error message makes that less likely).
For resolving error 26 in sql server you need to do the following steps.
At Server System
1. Under surface area configuration manager-Open up remote connections.
2. Add into firewall 1433 and 1434 port no as n exception.
3. Open port 1433 on router for WAN access.
4. Add client machine ip address as an exception to your antivirus or allow LAN settings in antivirus.
5. Now try to check if both client and server are connected to each other.
for this type "ping IP address of remote system" at run and if reply is obtained then do same for server machine.
If reply is obtained from both machines.
Open Sql server and try to connect to remote machine which allow remote connections using its ip address. U will surely get connected to server machine
See this video
Check to make sure TCP/IP is enabled on the SQL Server. For whatever reason, named pipes and TCP/IP is off by default. Also make sure you are trying to connect to the correct instance (maybe you are using ./SQLEXPRESS locally and on the server SQL is installed on the default instance). Lastly, make sure the database you are trying to connect to exists on the server.