Quick question - my LAN at home:
INTERNET (public IP)
v
ISP ROUTER (192.168.0.1, no access)
v
PERSONAL ROUTER (192.168.1.1, full access)
v
DEVICE (192.168.1.200)
Is it possible somehow to "expose" my device to the Internet, so I could remotely connect to it via ssh? Unfortunately I don't have an access to the ISP router, so can't setup port forwarding etc.
The cleanest solution would be to setup a VPN (i.e. openvpn) and connect to a VPN-server in the internet. Perhaps your PERSONAL ROUTER already has VPN-support in any way?
Drawback is, that you have to have an endpoint in the internet (a VPN-service or a (virtual) server).
Set up a reverse SSH tunnel from your home server to the machine you want to connect from, or at least to a machine outside your double NAT environment, such as a VPS.
On your home server, set up the tunnel like this:
ssh -fNTR $REMOTE_USER#$REMOTE_IP:localhost:22 $REMOTE_PORT
What do those flags do?
-f run in background
-N don't execute a command, we're just forwarding traffic
-T disable pseudo-terminal allocation to save resources
-R On the remote side, forward SSH connections from $REMOTE_PORT to your home server.
On your remote server, connect back to the home server on the tunnel you set up like this:
ssh $HOME_USER#localhost -p $REMOTE_PORT
Please share this with the other eleventy gajillion people on the internet who asked this and weren't answered.
Related
I am running a home network with a ddwrt installed router.
I can ssh into the router from homenetwork, i can ssh in the pc from inside the homenetwork, i can ssh into the router from outside the home network ( static public ip).
Now i want to ssh in my pc from outside the home network, as far as i have understood, to do that i need to create a ssh tunnel. I am using the following command :
ssh -L bbbb:hoomepcip:22 root:externalip
after doing this i open another terminal and i
ssh homepcusername#externalip -p bbbb
but it does not work, what am i doing wrong
Isn't the first command supposed to do a port forward in the router so everything i send to it's external ip on bbbb port goes to 22 of my home pc?
for now i have made a permanent port forward on the router gui, but i would like to not use that and open the port when i need to ssh.
both the router and the pc have SSH server installed, the router has dropbear the pc openssh
I found the solution for me.
So as i said i needed a way to ssh into my pc from outside my network through my router.
first open a terminal window and type
ssh -L bbbb:homepcIP:cc myrouterusername#mywanip -p aa
this will connect you to the router and forward port bbbb(chose a number from 1024-60000) to cc in your pc(usually 22)
type the password and leave it open
then open a new terminal window and type
ssh pcUSERNAME#localhost -p bbbb
bbbb in this case can be any port number you choose(best if above 1024, and max limit is 60000ish)
cc and bb are the port of the ssh servers (cc of my pc and bb of my router, they usually are 22 but it can change depending on conifguartion)
the key here is the "localhost" i always typed my pc ip in there but you have to type localhost and it connects to the pc correctly.
Also you have to have enabled SSH TCP Forwarding in the first server
Instead of SSH tunneling, you might consider tailscale.
See for instance "How to secure an Ubuntu server using Tailscale and UFW", which will restrict ssh access to be only over Tailscale, and use UFW (Uncomplicated Firewall) to restrict non-Tailscale traffic to your server.
That will give you a Tailscale IP address (starting with 100.x.y.z) which can be used to SSH, while your public internet IP would not allow SSH.
You can then add MFA (multi-factor auth) if you want.
Other example: "How to Setup SSH using Tailscale or Ngrok" from Ibrahim Jarif.
I would like to understand the concept of SSH tunneling in detail as I am learning a few things around this topic. I have gone through some details in public forum but still got a few questions.
An SFTP service is running in a remote server and I have been given credentials to connect to it. I am using GUI like WinScp to connect the remote server. What's the role of SSH tunneling here?
Remote SFTP Server admin asked me to generate RSA public key from my machine and its added to the remote server. Now, I can directly connect to the server from SSH terminal without password. What's the role of SSH tunneling here?
Is tunneling implicit or need to be called explicitly for certain circumstances?
Please clarify.
SSH tunneling, SSH console sessions and SFTP sessions are functionally unrelated things.
They can be used simultaneously during single session but usually it is not the case so do not try to find any relation or role of tunneling in ssh/sftp session.
It does not makes sense to mix ssh tunneling with multiple ssh/sftp sessions.
Basically you would use dedicated ssh session for tunneling and extra sessions for console and transfers.
What the heck SSH tunneling is?
Quite often both parties (you and server) reside in different networks where arbitrary network connections between such networks are impossible.
For example server can see on its network workstation nodes and service nodes which are not visible to outside network due to NAT.
The same is valid for the user who initiates connection to the remote server:
so you (ssh client) can see your local resources (worstation nodes and server nodes) but can't see nodes on network of remote server.
Here comes ssh tunneling.
SSH tunnel is NOT a tool to assist ssh related things like remote console ssh sessions and secure file transfers but quite other way around - it is ssh protocol who assists you with building transport to tunnel generic TCP connections the same way TCP proxy works. Once such pipe is built and in action it does not know what is getting transferred via such pipe/tunnel.
Its concept is similar to TCP proxy.
TCP proxy runs on single node so it serves as acceptor of connections and as iniciator of outgoing connections.
In case of SSH tunneling such concept of TCP proxy is split in two halves - one of the nodes (participating in ssh session) performs role of listener(acceptor of connections) and second node performs role of proxy (i.e. initiates outgoing connections).
When you establish the SSH session to the remote server you can configure two types of tunnels which are active while your ssh connection is active.
Multiple ssh clients use notations like
R [IP1 :] PORT1 : IP2 : PORT2
L [IP1 :] PORT1 : IP2 : PORT2
The most confusing/hard part to understand in this ssh tunneling thing are these L and R markers/switches(or whatever).
Those letter L and R can confuse beginners quite a lot because there are actually 6(!!!) parties in this game(each with its own point of view of what is local and what is remote):
you
ssh server
your neighbors who want to expose theirs ports to anyone who sees the server
your neighbors who want to connect to any service server sees
anyone who sees the server and want to connect to any service your
neighbor provides (opposite side/socket of case #3)
any service in a local network of server who wants to be exposed to
your LAN (opposite side/socket of case#4)
In terms of ssh client these tunnel types are:
"R" tunnel (server listens) - YOU expose network services from your LOCAL LAN to remote LAN (you instruct sshd server to start listening ports at remote side and route all incoming connections )
"L" tunnel (you listens) - Server exposes resources of its REMOTE LAN to your LAN (your ssh client starts listening ports on your workstation. your neighbors can access remote server network services by connecting to the ports of your workstation. server makes outgoing connections to local services on behalf of your ssh client)
So SSH tunneling is about providing access to the service which typically is inaccessible due to network restrictions or limitations.
And here is simple conter-intuitive rule to remember while creating tunnels:
to open access to Remote service you use -L switch
and
to open access to Local service you use -R switch
examples of "R" tunnels:
Jack is your coworker(backend developer) and he develops server-side code at his workstation with IP address 10.12.13.14. You are team lead (or sysadmin) who organizes working conditions. You are sitting in the same office with Jack and want to expose his web server to outside world through remote server.
So you connect to ssh server with following command:
ssh me#server1 -g -R 80:ip-address-of-jack-workstation:80
in such case anyone on the Internet can access Jack's current version of website by visiting http://server1/
Suppose there are many IoT Linux devices (like raspberry pi) in the world sitting in multiple home networks and thus not accessible from outside.
They could connect to the home server and expose theirs own port 22 to the server for admin to be able to connect to all those servers.
So RPi devices could connect to the server in a such way:
RPi device #1
ssh rpi1#server -R 10122:localhost:22
RPi device #2
ssh rpi1#server -R 10222:localhost:22
RPi device #3
ssh rpi1#server -R 10322:localhost:22
and sysadmin while being at server could connect to any of them:
ssh localhost -p 10122 # to connecto first device
ssh localhost -p 10222 # to connecto second device
ssh localhost -p 10322 # to connecto third device
admin on remote premises blocked ssh outgoing connections and you want production server to contact bitbucket through your connection...
#TODO: add example
Typical pitfalls in ssh tunneling:
mapping remote service to local priviledged port
ssh me#server -L 123:hidden-smtp-server:25 # fails
#bind fails due to priviledged ports
#we try to use sudo ssh to allow ssh client to bind to local port switches
sudo ssh me#server -L 123:hidden-smtp-server:25 # fails
#this usually results to rejected public keys because ssh looks for the key in /root/.ssh/id_rsa
#so you need to coerce ssh to use your key while running under root account
sudo ssh me#server -i /home/me/.ssh/id_rsa -L 123:hidden-smtp-server:25
exposing some service from local network to anyone through the public server:
typical command would be
ssh me#server -R 8888:my-home-server:80
#quite often noone can't connect to server:8888 because sshd binds to localhost.
#To make in work you need to edit /etc/ssh/sshd_config file to enable GatewayPorts (the line in file needs to be GatewayPorts yes).
my tunnel works great on my computer for me only but I would like my coworkers to access my tunnel as well
typical working command you start with would be
ssh me#server -L 1234:hidden-smtp-server:25
#by default ssh binds to loopback(127.0.0.1) and that is the reason why noone can use such tunnel.
#you need to use switch -g and probably manually specify bind interface:
ssh me#server -g -L 0.0.0.0:1234:hidden-smtp-server:25
Here's the thing. I'd like to access a remote host by ssh, and make a tunnel as a proxy. I did it on my windows computer with Putty. In putty, there is a "tunnels" options, add a dynamic tunnel would do the trick. That is, a (dynamic, that is in the putty's option, I don't really know what it means)tunnel at port 1111, and then I can access the internet though socks5 proxy 127.0.0.1:1111.
But now I want to make the tunnel on my openwrt router, 192.168.1.1, and access the proxy as 192.168.1.1:1111. I want to know how. There are two major question:
1.the proper command of ctl ssh to make a tunnel just as the putty did. I googled a few, but because of the 2nd question, I never know which one is correct.
2.how can I access the tunnel on the router though 192.168.1.1:1111. As I tried before with ss_local(another proxy program), I established a socks locally but it can never be accessed by my another LAN host. Are there some firewall things to do?
Does anyone know the answers? Thank you!
This is what I did to access remotely to my AP.
I used a SSH Reverse Tunnel to a remote server. Here I dump a simple script to achieve it.
key_ssh=/root/.ssh/id_rsa
user=root
ip='YOUR_SERVER_IP'
port='THE_PORT_YOU_WANT_TO_CONNECT_THROUGH'
#connect ssh
ssh -f -N -i $key_ssh -R 0.0.0.0:$port:localhost:22 $user#$ip
And in your remote server you type:
sudo su
ssh -p THE_PORT_YOU_WANT_TO_CONNECT_THROUGH localhost
You will be asked for the root password, type it and you're in.
I have remote host/server with ssh access.
I have my computer in my work network which can connect via ssh only
in within this network.
And i can not connect via ssh to other world because of port 22
blocked by firewall.
I am trying to create ssh tunnel to forward example localhost:80 to remote_server:22.(i suppose to connect via ssh to localhost and will be forwarded to my remote server)
I tried for example without proxy
sudo ssh -L localhost:443:remote_server_ip:22 root#remote_host_name
and with proxy
https://wiki.archlinux.org/index.php/Tunneling_SSH_through_HTTP_proxies_using_HTTP_Connect
I have read a lot and checked stackoverflow but it still is not clear for me how to resolve this issue.
Recently I buyed a Foscam wireless IP camera:
http://www.foscam.com/Products_List.asp?id=173
In my home, my laptop and my IP camera are behind a cable modem (my ISP gives me a dynamic IP) using a linksys router (I dont have a public IP).
Actually I use SSH in a basic way to learn / manage some basic things in my VPS server.
My question is (the right ssh flags and commands to achieve this):
I think that I need to create:
A tunnel from my local router to a remote VPS server where I have root access.
A portforward in the router.
Thanks in advance.
You need to add a port forward in your router from port X to port 22 on your home computer.
You can then ssh -p X username#your-home-ip.
Include the -L Y:foscamip:80 command line switch when you run ssh, assuming focscam runs a web server on port 80 (standard). Use something over 1024 for Y, like 8080.
Open up a web browser, and go to http://localhost:Y.
You have access! When you're done, simply log out of your ssh session.
Old question, but I will answer in the hope it helps someone like me. Given:
you have a VPS with root access at root#example.com
you have an RTSP-compatible IP camera in your LAN at address 192.168.1.100
you have a PC/router/Raspberry Pi able to create the tunnel
what I did was
ssh -N -f -R 10554:192.168.1.100:554 root#example.com
Exaplanation:
-N: don't execute any command via SSH
-f: put SSH in the background
-R: remote port forwarding
10554: a port to open on the VPS to access the IP camera (better if > 1024)
192.168.1.100:554: IP address and port you want to access remotely
root#example.com: user and address of your VPS
To access the RTSP stream of the camera, open rtsp://<username>:<password>#example.com:10554/<path-to-stream>.
Of course it works fine also for other kind of streams (e.g. HTTP).
Better yet, use autossh.
/usr/bin/autossh -N -f -M 0 -i /home/pi/.ssh/id_rsa -o "ServerAliveInterval 30" -o "ServerAliveCountMax 3" -R 10554:192.168.1.100:554 root#example.com.
I ended up with this command reading a lot of articles on the web. I even created an autossh user on the VPS without a shell, so it can do nothing apart from port forwarding.