Connection timed out, EC2 - amazon-ec2

Initially, ssh was working fine. But now says connection times out. The error is:
ssh: connect to host ec2-18-188-122-135.us-east-2.compute.amazonaws.com port 22: Connection timed out
I tried rebooting the instance and stopping and again restarting the instance still didn't work. Please help.
Instance Id: i-02fc8035a7f00d1be
The security group allows for ssh connection for port 22. I created new instance with the same security group and it works.But I need the original one to work.

Related

DBeaver connection via SSH tunnel

Using DBeaver, I'm trying to connect to my AWS ec2 instance where I've installed a MariaDB database.
I've created a new connection as:
Connection: AWS / Maria DB
Server Host: localhost (because I'm using ssh to connect)
Database, Username and Password: the right ones
Port: 3306
SSH tunnel on the connection:
Use SSH Tunnel: checked
Host/IP, Port and User: as suggested by the AWS documentation
Auth: Public Key
Private key: file .pem (the one I'm also using to connect via ssh from command line)
The connection works great at the beginning.
After some minutes of inactivity if I open a table the connection stucks and I need to invalidate/reconnect to fetch the data. This process sometimes is done by DBeaver, after 15 seconds of not fetching anything, but sometimes even if I wait 2 minutes it keeps running but fetching nothing.
Is there something I'm missing in my configuration? Or some configuration on the server maybe.. I don't know..
Have you ever had this problem?
Here I had the same situation. Previous versions of DBeaver used to keep the connection longer (I don't remember precisely which version), in the order of hours.
I solved this issue by using a VPN or a SSH port forwarding from my machine. So, it is the same configuration as yours with localhost, but the tunnel is done outside DBeaver.
config using pem key in shh tunel

VNC viewer failing to make connection with "channel 3: open failed: connect failed: No route to host"

I ssh into a server with the following:
ssh -g -L5912:server:5912 user#host
It goes through, and I can access my files on the other server through the command line (meaning I can connect to the server, it is my vnc viewer that is failing!) but when I try to open my vnc viewer (RealVNC) and connect to localhost:12 i get the following error message in the vnc viewer application:
The connection closed unexpectedly.
Additionally in the original command line shell i get:
channel 3: open failed: connect failed: No route to host
I've tried switching to different ports and even checked out other posts on the same error message but the problem is i don't really understand them... ssh tunnels are still relatively new to me so i don't really know what im doing. Any help would be greatly appreciated. Thanks!
You're trying to setup a port forwarding, this may fail because of many reasons:
SSH port forwarding not enabled in the host
Check SSH server in the host if AllowTcpForwarding is enabled:
$ grep AllowTcpForwarding /etc/ssh/sshd_config
AllowTcpForwarding yes
Typically, it's commented out. Uncomment and restart the sshd.
No connection between the host and server over port 5912
SSH to the host and try:
$ telnet server 5912
Connected to server.
Escape character is '^]'.
Finally, does the server listen on 5912?
Similarly, as above, but from the server - go there and try telnet server 5912.
Best regards,
Jarek
In my case it was the port forwarding rule I had set in Putty.
Please make sure you enter the correct hostname when defining the rule in Putty. I changed
localhost:5903
with
myserver:5903
and it worked...

Unable to log into Amazon EC2 instance from MacBook Pro

I'm trying to log into an EC2 instance I created on AWS with the following command:
sh -v -i MyEc2KeyPair2.pem ec2-user#54.146.40.216
After a while, I get a connection timed-out message:
# ssh -v -i MyEc2KeyPair2.pem ec2-user#54.146.40.216
OpenSSH_5.3p1, OpenSSL 1.0.1e-fips 11 Feb 2013
debug1: Connecting to 54.146.40.216 [54.146.40.216] port 22.
debug1: connect to address 54.146.40.216 port 22: Connection timed out
ssh: connect to host 54.146.40.216 port 22: Connection timed out
I've allowed all incoming for http, https, ssh and icmp. Although I allowed incoming pings on the server instance (icmp), a ping to the address just gets timeouts. A traceroute goes as far as the New York Comcast backbone, then starts showing asterisks. tcpdump with a grep on the address when I run the ssh shows only outgoing messages, with no incoming.
I also to ssh from a different server (a virtual host on bluehost), but got the same results. Obviously, I did a chmod 400 on the .pem as per Amazon instructions.
In case there was an error in the setup, I deleted and recreated the server, and am still having similar issues.
Any idea how to solve this? I'm stumped.
Edit: shown below are the input and outputs allowed per the security group:
The solution was to delete the instance and create another one.

Can only connect one time to AWS EC2 instance

I launched a new AWS EC2 Ubuntu Server t2.micro instance via the AWS console. I was able to successfully connect to the instance a single time using ssh on macOS Sierra 10.12.3:
$ ssh -i ./ubuntu-server-2-17-2017.pem ubuntu#ec2-55-555-555-555.compute-1.amazonaws.com
However, when I try to connect a second time, I get a time out error:
$ ssh -i ./ubuntu-server-2-17-2017.pem ubuntu#ec2-55-555-555-555.compute-1.amazonaws.com
ssh: connect to host ec2-55-555-555-555.compute-1.amazonaws.com port 22: Operation timed out
How can I resolve this issue?
The first thing to check is that the IP address associated with the instance is still the same.
The other thing to look at, then, is the security group to see if your IP address (which maybe changed) is still allowed.

SSH -L connection successful, but localhost port forwarding not working "channel 3: open failed: connect failed: Connection refused"

My lab runs RStudio on a server. A couple weeks ago, from my cousin's house, I successfully ssh'd into the server and pulled up the server-side RStudio through my local Firefox browser. Now when I try to access the server RStudio from home (via my own router), it doesn't work. I need help troubleshooting, and I'm guessing it's some problem on the router. I'm running Mac OSX 10.6.8. No idea what the university server's running, but I don't think it's a server-side problem.
Here's how it worked the first time I did it, at my cousin's house: first, I VPN into the university network; then I call SSH with port forwarding; then I open a Firefox browser, connect to my localhost port, and it opens up RStudio on the server side which I can access through my local browser window.
Here's the problem I'm having right now when I try to log-in from my home network:
I can make the VPN connection successfully. I can also set up SSH successfully with this command:
ssh -v -L 8783:localhost:8783 myacct#server.com
Here are the last several lines of the verbose output from the successful ssh command:
debug1: Authentication succeeded (password).
debug1: Local connections to LOCALHOST:8783 forwarded to remote address localhost:8783
debug1: Local forwarding listening on 127.0.0.1 port 8783.
debug1: channel 0: new [port listener]
debug1: Local forwarding listening on ::1 port 8783.
debug1: channel 1: new [port listener]
debug1: channel 2: new [client-session]
debug1: Entering interactive session.
Last login: Mon Sep 2 04:02:40 2013 from vpnipaddress
So I think I'm still succeeding at the VPN and SSH stage (though I don't know why it says my last login was Sep 2 when I've logged in a few times since then).
Next, I open Firefox, and I type localhost:8783, and instead of getting an RStudio server app through my browser window, I get the following errors:
In the Firefox browser window, it says: Server not found, Firefox can't find the server at www.localhost.com, Check the address for typing errors etc.
In the terminal window, it says:
debug1: Connection to port 8783 forwarding to localhost port 8783 requested.
debug1: channel 3: new [direct-tcpip]
channel 3: open failed: connect failed: Connection refused
debug1: channel 3: free: direct-tcpip: listening port 8783 for localhost port 8783, connect from 127.0.0.1 port 50420, nchannels 4
I'm not sure what I've got wrong. I haven't changed anything on my laptop since my last successful connection. I'm on my own router (instead of my cousin's), so maybe I need to mess with the firewall? I already allowed ports 22 and 8783 to come through the firewall to my laptop (I'm not even sure I needed to do that though). Help?
ssh -v -L 8783:localhost:8783 myacct#server.com
...
channel 3: open failed: connect failed: Connection refused
When you connect to port 8783 on your local system, that connection is tunneled through your ssh link to the ssh server on server.com. From there, the ssh server makes TCP connection to localhost port 8783 and relays data between the tunneled connection and the connection to target of the tunnel.
The "connection refused" error is coming from the ssh server on server.com when it tries to make the TCP connection to the target of the tunnel. "Connection refused" means that a connection attempt was rejected. The simplest explanation for the rejection is that, on server.com, there's nothing listening for connections on localhost port 8783. In other words, the server software that you were trying to tunnel to isn't running, or else it is running but it's not listening on that port.
Posting this to help someone.
Symptom:
channel 2: open failed: connect failed: Connection refused
debug1: channel 2: free: direct-tcpip:
listening port 8890 for 169.254.76.1 port 8890,
connect from ::1 port 52337 to ::1 port 8890, nchannels 8
My scenario; i had to use the remote server as a bastion host to connect elsewhere. Final Destination/Target: 169.254.76.1, port 8890. Through intermediary server with public ip: ec2-54-162-180-7.compute-1.amazonaws.com
SSH local port forwarding command:
ssh -i ~/keys/dev.tst -vnNT -L :8890:169.254.76.1:8890
glue#ec2-54-162-180-7.compute-1.amazonaws.com
What the problem was:
There was no service bound on port 8890 in the target host. i had forgotten to start the service.
How did i trouble shoot:
SSH into bastion host and then do curl.
Hope this helps.
Note: localhost is the hostname for an address using the local (loopback) network interface, and 127.0.0.1 is its IP in the IPv4 network standard (it's ::1 in IPv6). 0.0.0.0 is the IPv4 standard "current network" IP address.
I experienced this error with a Docker setup. I had a Docker container running on an external server, and I'd (correctly) mapped its ports out as 127.0.0.1:9232:9232. By port-forwarding ssh remote -L 9232:127.0.0.1:9232, I'd expected to be able to communicate with the remote server's port 9232 as if it were my own local port.
It turned out that the Docker container was internally running its process on 127.0.0.1:9232 rather than 0.0.0.0:9232, and so even though I'd specified the container's port-mappings correctly, they weren't on the correct interface for being mapped out.
In my case, it worked after running the vncserver on linux.
Entered this on linux command line : sudo ssh -L 5901:localhost:5901 -i <ssh_private_key> <username>#<public-IP-address>
Type there vncserver
Go to VncViewer application and connect using localhost:5901
I used to meet the similar problem because 'localhost' was not available on server when it restarted network service, e.g. 'ifdown -a' but followed by only 'ifup -eo1'. Besides server is not listening to the port, you can also check 'localhost' is available or not.
ps: Post it just hope someone who has the similar problem may benefit.
I had this problem when I wanted to make a vnc connection via a tunnel.
But the vncserver was not running.
I solved it by opening the channel on the remote machine with vncserver :3.
In my case, it worked after checking the correct IP address of the user credentials
previously I was using the wrong IP of the server
ssh -NfL 127.0.0.1:8084:127.0.0.1:8888 user#ip_address_of_server
after correcting it, works fine.
Encountered with the same error.
In my case, I found the problem was in the config file of jupyter.
Let's say there are 3 computers named A, B, and C, and A can access B but can't access C; B can access C.
To access jupyter-notebook service of C from A, first I established ssh tunnel from A to C through B, then I access jupyter-notebook by typing localhost:port_number, then I got the error.
Finally the problem was solved by writing the "c.NotebookApp.ip = '0.0.0.0'" in jupyter-notebook's config file, where '0.0.0.0' allows the access of other IPs.
Hope someone in a similar situation may benefit.
I had the same error when I was trying to tunnel my mlflow ui over ssh to view remotely. As mentioned in the first answer, the error arises because nothing on the server is listening for the port. This, for me, is because I forgot to start the mlflow app on my remote machine! So in general – make sure the app you're trying to access remotely is running.
Just replace localhost with 127.0.0.1.
(The answer is based on answers of other people on this page.)
This means the remote vm is not listening to current port i solved this by adding the port in the vm server

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