VNC viewer : Timed out waiting for response from computer - vnc-viewer

I am entering the ip of the machine I wanted to connect using vnc viewer but it's giving me this error:

So, that error means
No response was received from the specified IP address, even to reject
the connection.
Ways to fix this:
Check the remote computer is switched on. Ensure antivirus software lists VNC Server as an exception, and the firewall is configured to allow access on VNC Server’s listening port (5900 by default).
See if you are attempting to establish a direct connection over the Internet.
You can check any vnc error message from https://help.realvnc.com/hc/en-us/articles/360002254738-VNC-Connect-Error-Messages

Related

PostgreSQL Connection to the server has been lost

I installed postgreSQL server on a raspberry pi 4 with raspbian buster. When I try to connect from local network i have no problems about idle time. When i try to connect from my static public ip I can send command but if I didn't send anything for more than 3 minutes, it appears this message "Connection to the server has been lost".
I tried to install ufw and disable it, I used DMZ, I tried to change keepalive_idle, but i have always the same problem. Please help me.
sometimes the error is
"ERROR: SSL SYSCALL error: Operation timed out"
(Note: always if I am connected from public IP)
If you don't have the same issue from within your local network I assume the connection is being terminated by a network device sitting between the client and the server (a router most likely).
There are routers with small TCP timeout settings (such as 300 seconds) which is close to what you're experiencing.
Try to check (and increase if needed) the TCP timeout settings on your router (and any other devices you might have in between).
Edit:
I tried to find some info on that device (seems to be Sercomm VD625) and it does not seem you can easily change TCP timeout settings (maybe via telnet/ssh if it supports it).
However, a simpler solution might be to avoid keeping an open connection to PostgreSQL if you will have large idle intervals; just connect when you need to and close the connection afterwards.

SMTP errors from web server

I am having issues with SMTP from one of my web servers. I've verified firewall connectivity over port25 to the SMTP relay and the exchange servers is good to go. I can hit the SMTP relays and exchange server from my web server via telnet. Whenever I drop a mail in Pickup it sits in the queue.
In Event Viewer I get:
Message delivery to the host 'IPADDDRESS' failed while delivering to the remote domain 'MYDOMAIN' for the following reason: The connection was dropped by the remote host.
I checked SMTPDiag and it comes back:
Error: Expecting "220". Server is not accepting connections.
Failed to submit mail to "server.domain.com"
I checked and my connection control is set to allow and the domains are listed in SMTP.. I am losing my mind trying to figure out why mail is failing at this point..
Are you hitting a rate limit or is your outbound ip on a blacklist? Try the blacklist search here: https://mxtoolbox.com/supertoolmobile.aspx

unable to connect to openfire server with external ip

I'm trying to connect to openfire server using spark. I have dynamic dns, made port forwarding on port 5222 in d-link router. When i'm logging with host name as private ip for example "192.168.0.101" - connection is established, but when i'm setting my domain (pizokas.hopto.org) as host name i get the following error
Unknown connection error. Please review logs for the following information.
But there are no logs in openfire server, so i assume packets are dropped in router. I have firewall turned off. At this point i can't find information why the connection cannot be established. I'm using my own laptop as server and as a client, os win 10. Maybe somebody had similar issue?
The connection was established when i was trying to connect to server from outside of lan

Access application Using url in other Machine

I have web apllication which runs in localhost using eclipse,i am trying to access that from
other computer using URL...but the browser throwing error.
The connection has timed out
The server at xyz.xyz.1.2 is taking too long to respond.
The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer's network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the We
the URL looks like this:xyz.xyz.1.2:8080/MyProject/GetUserSMSAction and the server is
running in xyz.xyz.1.2..:(
The port 8080 is probably not oppened on your computer.
If your network administrator won't open it, try changing the configuration to use the port 80 and this will solve your problem.

Can't connects XenCenter with XenServer

I am trying to connect XenCenter 6.0 to Server installed with XENSERVER 6.0 but i can't connect.
It give me error when i try to connect :
"Unable to connect to server '192.xxx.xxx.xxx'.
The connection was refused.
Check that Xenserver is configured correctly on '192.xxx.xxx.xxx'."
Also When i was using another computer for connecting xencenter, It was disconnecting automatically every time i connect
Examine some details:
List item
the server is power-on
the network configuration is right.(try to use "ping" or "ssh" to check)
the firewall setting
duplicate IP address which has been used
There are two possible scenarios in this case .
Either
1. The xenserver physical machine is powered off.
Or
2. The network cable is not connected properly.
If the server is pingable, make sure xapi and xapi-ssl are running.
ssh to the xen server and check the following:
/etc/init.d/xapi status
/etc/init.d/xapi-ssl status
If they are not running restart them
/etc/init.d/xapi start
/etc/init.d/xapi-ssl start
might require a xe-toolstack-restart