I´ve got a Server behind a firewall and the firewall only allows traffic through port 22. This server has both public and private addresses.
I´ve got also about 1K clients that I need to reverse shell to this server, and be able to choose one of them by id when I want that ssh reversed tunnel.
My goal is to make the clients connect to ssh server via port 22, and each one of this connections should be forwarded to localhost on port with the same id.
When I connect to the server with my laptop also via ssh, I would then ssh to localhost on the correct id and get the client shell.
Can someone provide me the good path to achieve this behaviour using bash, ssh and linux tools?
Note - I don´t want to use client.py and server.py cause most of my clients are android based and it could easily become a nightmare to install python on all of them.
The problem - it was solved using remote port forwarding:
ssh -R 21:localhost:8888 user#server
In this command the 8888 represents the terminal id. In order for this to work, had to add this line to my ssh conf:
GatewayPorts yes
Related
Need to reach phpMyAdmin on an EC2 instance behind a bastion/jumpserver from local laptop.
Looking to reduce these steps into using .shh/config. The question seeks to solve the right configurations.
When connecting to EC2 without public bastion server to jump through, this is the normal way documented which does not work in my case because our deployment uses a public facing bastion:
https://docs.bitnami.com/aws/faq/get-started/access-phpmyadmin/
When you need to jump through a public facing bastion e.g.:
Local/Laptop ------> bastion/jumpserver -----> ec2
This above reference link does not follow the same workflow and documentation is sparse.
Setting up inbound/outbound rules for this capability is also sparse.
The preference is to use .ssh/config which is setup like this:
Host bastionHostTunnel
Hostname <publicBastionIp>
User <bastionusername>
ForwardAgent yes
IdentityFile <local path to .pem file>
Host ec2Host
Hostname <privateEC2IP>
User <ec2 username>
ForwardAgent yes
IdentityFile <local path to .pem file>
# -A Enable forwarding of the Authentication agent connection
# -W used on older machines instead of -J to bounce through
# %h the remote hostname
# On Windows 10(only?) seems must call ssh.exe instead of only ssh
ProxyCommand ssh.exe -A -W %h:22 bastionHostTunnel
I obviously left out vars in <> above - but I have them and have verified similar configuration is working for enabling SFTP as above with FileZilla.
Then in shell call this to bind port localhost:8888 (http://127.0.0.1:8888):
ssh ec2Host -D 8888
Then ought to be able to open browser and go to the following to access phpMyAdmin:
http://127.0.0.1:8888/phpmyadmin
Current issue is that this process is hanging and possibly refusing the connection. This points to either bad configuration above or incorrect inbound/outbound rules for either/both bastion and ec2 instance.
Has anyone here had similar issue and was able to solve and could share further, much appreciated. Plus any extra clues as far as debugging the overall process would help in the answer.
I'm most curious if it works if you specific everything on the command line...once you determine that works, you can start refactoring to put some aspects in to .ssh/config. It's usually easier for me to find errors with my configuration if everything is on the command line, plus I don't know that I see the correct forwarding options all listed there.
Unless I'm very mistaken, you don't need any reference to the ec2 host in your SSH config file because you're using the jump machine to redirect localhost traffic there, you wouldn't directly be able to reach the ec2 host machine from your local machine using an SSH tunnel.
There are many ways to do a tunnel, but when I do this, I use a command like ssh -L 8080:destination:80 -i <keyfile> me#jumpbox . destination must be reachable from jumpbox, which I can verify by first using ssh -i <keyfile> jumpbox then, once on that machine, ssh destination. If there's a problem along the way, it's easier to debug these little steps (for instance, if I can't connect by manual ssh to jumpbox then I know the tunnel will never work).
I've created SSH tunnels in the past, but I'm having trouble on OSX. I'm looking to take a website's port 80, and direct it to my localhost:8080. When I run this command
ssh -L 8080:<cloud_ip_address>:80 root#<cloud_ip_address> -N
I get the default apache 'it works!' page.
Why am I not getting the port 80 of the remote machine (which is running a web app)?
UPDATE
I still do not have a solution yet, but I have some more information. The page I am getting is the default page in /var/www/html but I am serving a Flask app which does not have static pages.
Because HTTP protocol contains not only the IP address, but also the hostname (the URL you type into your browser), which differs between the <cloud_hostname> and localhost. The easiest way to trick it is to create /etc/hosts (there will be some OSX alternative -- search ...) entry redirecting the hostname of your remote machine to localhost.
127.0.0.1 <cloud_hostname>
But note that in this case you will not be able to access the remote machine using the hostname!
I was using putty SSH to tunnel out ( from office network ) to our VM on public cloud when I was using Windows. In Putty, I can specify proxy with HTTP and specify user name and password ( our proxy need password).
Now I change my work to Mac, but when I try to tunnel by SSH to outside, since Mac don't have putty, I can only find default SSH command on Mac. When I try to specify SSH proxy on Mac SSH command. I could't find any useful example about how to do it. Is any body have experience on that?
Thanks,
Xinsong
Manual pages are your friends. There is -D switch for ssh command:
-D [bind_address:]port
Specifies a local “dynamic” application-level port forwarding. This works by allocating a socket to listen to port on the local side, optionally bound to the specified bind_address. Whenever a connection is made to this port, the connection is forwarded over the secure channel, and the application protocol is then used to determine where to connect to from the remote machine. Currently the SOCKS4 and SOCKS5 protocols are supported, and ssh will act as a SOCKS server. Only root can forward privileged ports. Dynamic port forwardings can also be specified in the configuration file.
IPv6 addresses can be specified by enclosing the address in square brackets. Only the superuser can forward privileged ports. By default, the local port is bound in accordance with the GatewayPorts setting. However, an explicit bind_address may be used to bind the connection to a specific address. The bind_address of “localhost” indicates that the listening port be bound for local use only, while an empty address or ‘*’ indicates that the port should be available from all interfaces.
I am trying to run putty on Windows 7.
I need to run some SSH commands to upgrade Magento. Every time putty gives me this fatal error:
network error: connection refused
I have even tried to use it through winSCP. Note that putty is running fine on my client's side, but for me it's giving me that error every time.
I tried using port 22, 23 and a few others without success. I have also tried with Windows Firewall both enabled and disabled.
Thank you.
Install open-ssh or ssh in target Linux machine solved my problem .
Use below commands:
sudo apt install ssh
sudo systemctl status ssh
sudo systemctl enable ssh
The following are the list of possibilities of this error:
1) Common cause is - Your IP is blocked or not whitelisted in the server which can be done by editing the file at /etc/csf/csf.conf
2) Disable the windows firewall settings and check..
The above two things should work in most of the cases
3) This is very unusual and when the above two options fails it is very difficult to find the solution
In this case the traceroute to the server host or IP works usually but putty fails
port 22 looks normal and working but connection fails and restarting SSH (service ssh restart) also does not work
reboot or restart the server but still fails
Adding IP in firewalls or whitelisting the local IP may not workout
This case generally happens when the server is migrated or new server. IP of the old server might be whitelisted locally, but don't have port 22 open, or some other local filtering is occurring for this new IP but not the old server IP..
In this case you need to change the port to some 522 or 530 some unusual port will help in sorting it out.. The same port you have to use for the SFTP connection also .. where as FTP connections works normally..
or you have to whitelist the IP locally or open the TCP in and out to port 22 if you want to use the port 22..
A service, for example an FTP server, only accepts connections from a specific network, where all users will have the same external IP-adress.
I want to connect to this service, but I'm currently not inside the allowed network.
I have ssh access to a server inside the network.
How do I use ssh to tunnel a certain port from my local machine, through a machine on the internal network, to the final service, so that any client opening the correct port won't notice any difference?
You can create a SSH tunnel to your specific network using the following command.
For instance, let's say you want to reach a web service on computer "mywebserver" (port 80).
Under Linux or BSD, using OpenSSH, you can use the following commandline:
ssh -f mysshserver -L 1234:mywebserver:80 -N
Under Windows, you can use MobaXterm which includes a simple graphical ssh tunnel builder
This will open a SSH tunnel between local port 1234 and remote webserver on port 80. You can then open your web browser and connect directly to your web server by typing "http://localhost:1234" in the address bar.