sendmail SMTP connection timed out error at MATLAB - java

Kindly, I have the mentioned error for this code when running on Wifi while it works when using phone 3G hotspot:
username='XXX#hotmail.com';
pass='XXXXX';
port='587'; % hotmail
props = java.lang.System.getProperties;
props.setProperty('mail.smtp.starttls.enable', 'true' );
props.setProperty('mail.smtp.auth','true');
props.setProperty('mail.smtp.socketFactory.port',port);
setpref('Internet','SMTP_Server','smtp.live.com');
setpref('Internet','E_mail',username);
setpref('Internet','SMTP_Username',username);
setpref('Internet','SMTP_Password',pass);
sendmail(username,'Available');
Error:
Error using sendmail (line 171)
Could not connect to SMTP host: smtp.live.com, port: 25;
Connection timed out: connect
Should I change anything in the router settings?
enter image description here

You might have port 25 blocked. Try this:
telnet smtp.live.com 25
and copy results here.
Port 25 is often blocked by ISP to prevent spamming.
If you use Windows OS, you may have telnet client switched off in your system, so you are not able to use it in your command window (cmd). Go to Control Panel -> Programs and Features -> Turn Windows Features on or off and check Telnet Client.

Related

java: getting Connection refused when trying to upload file to FTP

When trying to upload file to FTP with java program:
public void upload(String localFile,String remoteFile) throws Exception{
ftp = new FTPClient();
ftp.setControlKeepAliveTimeout(300);
ftp.connect(host,21);
ftp.enterLocalPassiveMode();
ftp.setUseEPSVwithIPv4(false);
ftp.login(user,password);
ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
FileInputStream in = null;
in = new FileInputStream(localFile);
ftp.storeFile(remoteFile,in);
in.close();
ftp.disconnect();
}
I'm getting:
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:381)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:243)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:230)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:377)
at java.net.Socket.connect(Socket.java:539)
at org.apache.commons.net.SocketClient._connect(SocketClient.java:243)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:202)
When I try to upload the same file with command line (from linux), I'm able to do it only when using EPSV:
llnx:~ ftp anonymous#9.20.1.116
Connected to 9.20.1.116.
220 Microsoft FTP Service
331 Anonymous access allowed, send identity (e-mail name) as password.
Password:
230 User logged in.
Remote system type is Windows_NT.
ftp> epsv
EPSV/EPRT on IPv4 off.
ftp> put /tmp/file1.xml /dir_1/file1.xml
local: /tmp/file1.xml remote: /dir_1/file1.xml
227 Entering Passive Mode (10,40,1,149,233,168).
125 Data connection already open; Transfer starting.
100% |*************************************| 117 KB 28.66 MB/s --:-- ETA
226 Transfer complete.
120032 bytes sent in 00:00 (7.96 MB/s)
So, Why does my java code getting Connection refused?
Maybe I'm not using the enterLocalPassiveMode() or setUseEPSVwithIPv4() method the right way?
*** I think the answer is how to run the EPSV command from Java program.
Thank you all.
Eithan.
This is purely a guess but java.net.ConnectException: Connection refused normally happens when there is nothing listening on the target host/port. You don't specify a port in the CLI example so maybe that is the problem. Try changing ftp.connect(host,21); to ftp.connect(host); to use the default. Also confirm the the hostnames are exactly the same.
This assumes that the error is on the call to connect(). You haven't provided a big enough stack trace to indicate either way.
Connection refused means that your TCP connection request has reached the remote server (or more correctly >>a<< remote server) but the server is not expecting / listening for an incoming connection. So it "refuses" it.
Here are the things to check:
Check that you have the correct remote hostname or IP address for the FTP server.
Check that you are using the correct port for the FTP server. Port 21 is the default, but it is possible that the server is on a non-standard port.
Check that the FTP server is actually running.
It is also possible that the problem is due to a firewall doing something deliberately confusing. But that is unlikely for a publicly routable FTP server.
Maybe I'm not using the enterLocalPassiveMode() or setUseEPSVwithIPv4() method the right way?
That can't be the problem. The stacktrace shows that your application failed while trying to establish the initial connection to the server. You haven't gotten to the point where the you can make those calls.

Problems when trying to attach to a process using jdb

I need to attach a jdb debug session to a java application that is being executed in a remote host, but I am unable to do it. I am working on linux, with openjdk 1.8.0_65, 64-Bit Server VM.
What I have tried
In order to enable the port listening, I have run the java application adding the following arguments to the command line:
-Xdebug -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:8000,server=y,suspend=n
The following message is displayed in the console:
Listening for transport dt_socket at address: 8000
And the application starts running normally.
Then, from the remote host, I execute the following command:
> jdb -connect com.sun.jdi.SocketAttach:hostname=<remote_host>,port=8000
It fails, the output is:
java.net.ConnectException: Conexión rehusada
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
[...]
Fatal error:
Unable to attach to target VM.
What I have checked
In order to check that the port is actually open and I can connect to it from the remote host, I have performed the following operations:
Lets call the host that is executing the java app. hostA, and the one from which I wan to attach the jdb hostB, then:
Check that there is actually a socket listening on port 8000 in hostA
> netstat -tualpn | grep :8000
tcp 0 0 127.0.0.1:8000 0.0.0.0:* LISTEN 1399/<app_name>
In hostA, check that I can connect to the port 8000 (in other words, try to connect from the local host)
> nc -vz localhost 8000
nc: connect to localhost port 8000 (tcp) failed: Connection refused
Connection to localhost 8000 port [tcp/irdmi] succeeded!
With telnet, it seems that it can connect but the connection is closed as soon as it is stablished, maybe because the JVM is expecting some sort of request?
> telnet localhost 8000
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
The java app. displays the following message when telnet connection is closed:
Debugger failed to attach: timeout during handshak
From hostB, check that I can connect to hostA, port 8000
> nc -vz hostA 8000
nc: connect to hostA port 8000 (tcp) failed: Connection refused
With telnet:
> telnet hostA 8000
Trying 172.17.10.127...
telnet: connect to address 172.17.10.127: Connection refused
So, I can't connect from hostA to hostB through the port 8000, although the JVM is listenning in the port 8000, in hostA.
Since the above fails, I have checked if the firewall is causing the connection refused. I have done it by using the nc command:
In hostA:
# First kill the java app (otherwise the port is busy), then:
> nc -l 8000
In hostB:
> nc -vz <hostA> 8000
Connection to hostA 8000 port [tcp/irdmi] succeeded!
As far as I understand, the above means that there is no firewall (or equivalent) blocking the port.
EDIT
Of course, I have tried to do jdb -attach but it fails even doing it from hostA.
I don't have enough points to comment. So I'm including this as an answer. It really isn't. BUT:
-Xdebug -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:8000,serv=y,suspend=n
Isn't it supposed to be:
-Xdebug -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:8000,server=y,suspend=n
??
[EDIT] You are probably already accounting for this - but also, if you are listening on 127.0.0.1, then it stands to reason that you won't connect from a remote computer. No doubt you are using an actual address, and just didn't include it here...
I have found the connection problem. In the command I use to launch the java application, I have changed the address parameter as following:
Before:
-Xdebug -agentlib:jdwp=transport=dt_socket,address=127.0.0.1:8000,server=y,suspend=n
After (see address):
-Xdebug -agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n

TightVNC Java Viewer connection

I have source code of the tight VNC and installed 'Real VNC' on my local system. When I run the source of tight VNC, it asked for the host and port so I passed following credentials: Host: 127.0.0.1 Port: 5800. Then I can see the status as connected on the console of my eclipse. But I am not able to see my local screen. Can anyone help me that how can I record my local screen using tight VNC?
I am getting EOF exception.
Port: 5800 is a port that is mostly used by webSocket connections.
Try connecting through standart VNC port 5900.

Android Emulator get port Number

The port for emulator 5554 is not working when I try to type the command: telnet localhost 5554
The error is:
Connecting To localhost...Could not open connection to the host, on port 5554:
Connect failed
How could it connect to port 5554 to let the android emulator sending socket, and the android emulator program on client server side give a message that does not work ( unfortunately client has stopped)
Check whether your port is open or not using this link.
http://www.yougetsignal.com/tools/open-ports/
If u have personal firewall try disabling that.

Connection problem with sockets in java

i tried this code:
http://programming-guides.com/java/tcp-client-server-chat
(full example)
and it's working but when i switch the "host" int the client side to an external IP (insted of localhost) it give me this error:
"Cannot get IO for connection to.."
i treid to switch the port but it didnt work..
Is the server running on that remote machine? Is the port open in the firewall?
Try to netcat to the remote host. If you get an connection the example maybe wrong. If not, you cannot connect to that host: host not exists, not listen on that port, port is filtered, etc, etc.

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