'How to SSH tunnel from jump server to another server without directly logging in to the jump server

I know, this question has been asked a lot, but still I have problems using ssh proxy.

I have an EC2 server (running a simple web server) which is in a private network in aws. And have a jumphost to connect to it. jumphost is in a public network. Only way I can login in to the web server instance is through the jumphost.

So I have created ~/.ssh/config file in my local computer as below:

Host jumphost
  Hostname <Retracted-Public-IP>
  user ec2-user
  IdentityFile /Users/jananath/.ssh/private-key.pem

I can log in to the jumphost as: ssh jumphost and it works.

And in the jumphost above I have configured ~/.ssh/config as below:

Host my-web-server
  Hostname <Retracted-Private-IP>
  user ec2-user
  IdentityFile ~/.ssh/web-server-private-key.pem

And I can ssh into the web server (from jumphost) as ssh my-web-server and it works.

I don't want to log in to the jumphost everytime I need to log into the web server, so I tried proxying.

Therefore, I added another block to my local ~/.ssh/config file as below:

Host jumphost
  Hostname <Retracted-Public-IP>
  user ec2-user
  IdentityFile /Users/jananath/.ssh/private-key.pem

Host my-web-server
   ProxyCommand ssh jumphost -W %h:%p

And I tried: ssh my-web-server and it gives the below output:

kex_exchange_identification: Connection closed by remote host Connection closed by UNKNOWN port 65535

Can someone help me fix this?

linuxsshssh-tunnellocaltunnel


Solution 1:[1]

This should work :

Host my-web-server
   ProxyCommand ssh jumphost nc %h %p

You can also try :

ssh -oProxyCommand="ssh -W %h:%p jumphost" my-web-server

Third command worth to try :

ssh -J jumphost my-web-server

Solution 2:[2]

Copy the public key of your local machine to ~/.ssh/authorized_keys of the remote machine and not just the jump server. This will enable passwordless login from the local machine using ssh -J. If your ip is ipv6 make the following modification in the config file of your local machine.

Host jumphost
  Hostname Retracted-Public-IPv6
  user ec2-user
  IdentityFile /Users/jananath/.ssh/private-key.pem

Host my-web-server
   ProxyCommand ssh jumphost -W %[h]:%p

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 nidooooz

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