Ssh Port Number In Linux



All that's left to do now is to set up a local route to get some traffic into it. Using this technique we maintain one or more previously configured ports closed and these will only be opened using a sequence of requests to a number of ports that wepreviouslyset. the SSH is on router itself, not machine within my LAN. Introduction. But the good news is, we can change SSH port in Ubuntu to avoid getting unwanted login attacks by bots who attack on default ports. Changing the SSH Port for Your Linux Server You can change the default SSH port for your Linux server as an added security measure. In this tutorial we will look how to change the default port number from client and server point of view. When used with the -O forward option, the client will print the allocated port number to standard output. source is /opt/backup. Here we will change the port in Centos 6. Port 22 Details. Even though Secure Shell (SSH) allows you to have a secure connection with your remote server, changing the standard SSH port number is necessary for the sake of your VPS security. Before restarting the ssh server to make the change effective, it's really important to modify the firewall rules accordingly to the change. Changing The SSH Port Number. Depending on your Linux distribution and version this will be done either via sudo service sshd restart or sudo /etc/init. For detailed steps on installing the SSH server on an Ubuntu Linux system see Configuring Ubuntu Linux Remote Access using SSH. In fact, SSH1 and SSH2 are two entirely different protocols with no compatibility in between. You can connect to the Kali session remotely using the IP address assigned to your Android device (in my case, 10. As it is working over network connection and uses TCP it has a default port number which is 22. Enter the local port (e. You can also launch PuTTY from the Windows programs list. Accepting this value does not make your system insecure, nor will changing the port provide a significant variance in security. Specify a port number greater than 1023 and less than 49152 to avoid conflicts with ports that are reserved for the system. Port Number: TCP: 3351: TCP: 1583: TCP & UDP: 137-139 (used for authentication – which uses named pipes). ssh (SSH client) is a program for logging into a remote machine and for executing commands on a remote machine. Depending on your Linux distribution and version this will be done either via sudo service sshd restart or sudo /etc/init. In short, you need to enter the port number where requests will be made (Default SSH port is 22) and the private IP address you found earlier (using the ip a command) of the machine where the SSH is running. In Ubuntu (like other Unix-like systems), it was very straight forward to change the default SSH port number by modifying "Port 22" in "/etc/ssh/sshd_config". Open the SSH configuration file /etc/ssh/sshd_config in any text editor. Galbraith and R. How to connect from ssh to another host if random port number used instead of "22": #ssh -p e. The Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) use port numbers for communication. The notion is since SSH default port number is 22 and everyone knows it, including the hackers, it isn’t safe. allow Many have reported configuring these to values properly has helped. deny and /etc/hosts. List the added keys: ssh-add -l. OK, so I did manage to Putty SSH local port forward correctly after all: L3389 :3389 then from local Windows connect to localhost in your RDC connection params (not your remote Linux host IP!). Most Linux distributions feature the OpenSSH client today, but if you want to be sure, have a look at the SSH manpage on your system. SSH Port Forwarding in Linux: Configuration and Examples Submitted by Sarath Pillai on Tue, 11/19/2013 - 01:32 During the mid 90's (1995 to be precise) one researcher named Tatu Ylönen, at the university of Helsinki (Finland) designed a protocol, that eventually replaced all remote login programs. One of the most basic utility of SSH protocol is the ability to access Unix shells on remote Linux machines and execute commands. Service detection is enabled with the command Nmap -sV. how to setup ssh server on kali linux – using putty To finish up learning how to setup SSH server on Kali Linux you need to open up Putty that you should have already downloaded. Today we are going to show you how to configure and use OpenSSH on a Linux VPS using CentOS 7 as an operating system. env file to specify the new port. How to secure SSH service with Fail2Ban port = ssh. local-port is the number of an available port on your Linux system. The SSH (Secure Shell) port is 22. $(date +%F) [/code]Now edit the file /etc. After executing this script, the port number of your SSH server will be reset to its default value 22. The default port on which SSH service works is 22 (which is configurable) to exchange data between the remote users and the server. com sshd[6938]: Connection closed by 10. SSH servers use port 22 by default, but servers are often configured to use other port numbers instead. The Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) needed only one port for full-duplex, bidirectional traffic. conf file only allow local connections or non-SSH traffic is blocked by. You can create SSH alias to frequently-accessed systems via SSH. First: Modify the / etc / SSH / sshd_config configuration file (note: this is sshd_config, not ssh_config). ssh [email protected] Rather than have the port number in the URL, you may wish to set up port forwarding so that connections to the default SSH port are forwarded to the port Bitbucket Server is listening on (e. SSH or Secure Shell, in simple terms, provides commandline access to a remote system running SSH server. Examples of commands that would need the new port number specified include scp and rsync. If you are not used with SSH tunnels, here is a simple graphical explanation on how a simple SSH-tunnel works: This screenshot explains local port-forwarding mechanism: local clients need to connect to a remote server which cannot be reached directly through network. Secure Shell (SSH) t unneling or port forwarding capab ilities allow users to establish a secure link for data traffic that otherwise flows in the clear over communication links. You simply need to set the database client to use 127. Using the "ssh" command we can bind a desired port on a. PuTTY as an SSH and Telnet client was originally developed by Simon Tatham for the Windows platform. –limit-burst 100: This value indicates that the limit/minute will be enforced only after the total number of connection have reached the limit-burst level. Additional utilities, such as scp and sftp , provide secure file transfer services. To change the ssh port number. the print output need to be only 1 port, and it will be nice if the output will be saved as a variable or in same file. If you are running windows client program you should configure it in Putty client. Why We Change Default SSH Port? We change Default SSH port to provide security measures to the server especially from Brute Force Attack. org PING onofri. Here is a short post to check port [TCP/UDP] connectivity from a Linux server. What is a port? A port is piece of software which is used as docking point in your machine, where remote application can communicate. pssh is a program for executing ssh in parallel on a number of hosts. If selinux is enabled, you have to add new port number to selinux configuration because of the fact that selinux allows only 22 port number for ssh connections. Port 22 is the standard port for SSH connections. The connection details to consider during basic network daemon troubleshooting are the addresses that the daemon is listening on (including the port number), the daemon’s process identifier (PID), and the. This is the line we will want to change. You must type the following command to change port to 2222: # semanage port -a -t ssh_port_t -p tcp 2222. In this article, we will be using the Winbox application. Display the contents of the file banner before user login (default: none). Hi, I'm running centos 5. After logging in, you will find yourself in this add-on’s container. For the configuration in putty, give the IP address in hostname along with the port number and then select SSH and then finally click on Open. 1, which is the server itself. Connecting to an Alternate SSH Port. We offer two Linux distros: – CentOS Linux is a consistent, manageable platform that suits a wide variety of deployments. To use the secure tunnel, point any VNC client on your system to localhost:10903, rather than the actual server and port number. Open the SSH configuration file /etc/ssh/sshd_config in any text editor. The default port on which SSH service works is 22 (which is configurable) to exchange data between the remote users and the server. An example of working of the above syntax is $ rsync -av --rsh='ssh -p22' file1 [email protected] In this guide, we will discuss how to use SSH to connect to a remote system. From now on, you will be able to connect via SSH using your newly updated port number. In short, you need to enter the port number where requests will be made (Default SSH port is 22) and the private IP address you found earlier (using the ip a command) of the machine where the SSH is running. Note: It is not a general requirement of SSH tunnels that the port numbers match. Save the changes to the /etc/ssh/sshd_config file, and then exit the text editor. Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. SSH Port Forwarding for TCP. In this example we will connect port number 2134. I wrote the initial version of SSH in Spring 1995. PuTTY is open source software that is available with source code and is developed and supported by a group of volunteers. Then you need to edit the line that refers to the port number, for that you have to follow the. The main use of the open SSH command is to log into the host. It could save you from unnecessary attack specifically from bots and port scan attack. Changing the SSH Port in Linux Server I want to discuss few points about changing the SSH Port on a CentOS server. in the dynamic range of 50-65K) is therefore quite effective. However, changing the default SSH port will stop attacker from making unauthorized access or from many automated attacks and a bit harder to guess on which port SSH is accessible from. Inside the terminal window, SSH to the remote PC hosting SSH server. Both ends of the client/server connection are authenticated using a digital certificate, and passwords are protected by being encrypted. This rule will Allow ssh protocol (which use TCP port 22 by default) from the Ubuntu Firewall. So now I’m posting this litte tutorial, for those that want to work by the linux shell B). after authentication, you are able to do remote administration. Recently there was a need to connect to a SSH server from my C# code. Avoid using the local port numbers 0-1024 (root privilege required), 5900 (for Mac systems, reserved for some Apple remote desktop products), and 6000-6063 (reserved for local X window server). Ans : Yeah, everyone knows the default port number of SSH and which is port 22. Being able to modify this SSH port number on your CentOS 7 server is an easy and proven way that you can enhance server security by switching to a less-commonly known port. Also, note that once your default SSH port is changed you also need to change the way of using some of the commands. XX) and SSH2 (SSH version 2. After some hours surfing the web and making experiment, I could make it. One of the most common tasks when setting up a SSH server is to change the SSH port. In the following example, plink will connect to the remote Linux server on port 25. As vulnerability was reported from here, new version 1. Viewing or choosing a new SSH port number in Linux A note about SELinux users. Warning: Make sure the new SSH port does not conflict with any known or blocked ports. In one window, run a test server on an alternate port (here 1234) in debug mode: myserver# sshd -d -p 1234. org PING onofri. The -P (note: capital P) option can be used with SFTP and scp. You should consult your router documentation about how to set up port forwarding. Tunneling VNC Through SSH and Connecting. If you are having Amazon cloud server, the port number should be opened in the security group. I've started sshd on a particular range of port numbers and NATing a range of devices to those. Today, in this brief tutorial, we are going to see the easiest and quickest ways to find the port number of a service in Linux operating system. Dedicated and VPS customers automatically have root SSH access. In other words, your desktop remains active across your connections to it. Simply change the port number from 22 to any number you like. As a good practice, and for the sake of simplicity, you should specify the same port number as the one to which you are creating a tunnel. how to setup ssh server on kali linux – using putty To finish up learning how to setup SSH server on Kali Linux you need to open up Putty that you should have already downloaded. Di komputer client harus sudah terinstal ssh client, baik itu putty, winscp dll, kalo saya sih lebih suka pake putty. To simplify the process of connecting ParaView to HPC resources, we have developed a ParaView connection definition (. Changing The SSH Port Number. Changing SSH Port. Harris, Improved Arcfour Modes for the Secure Shell (SSH) Transport Layer Protocol, RFC 4345, January 2006. Backup existing config cd /etc/ssh cp sshd_config sshd_config_bkp 2. Options: You can use this text box to specify additional parameters to pass to the SSH client. Ports are classified into 3 main categories. modern Linux The "-n" option can specify the SSH port number(s) to scan. The default port on which SSH service works is 22 (which is configurable) to exchange data between the remote users and the server. A vulnerability has been discovered in the Linux sudo command that could allow unprivileged users to execute commands as root. An SSH client connects to a Secure Shell server, which allows you to run terminal commands as if you were sitting in front of another computer. Use the adduser command to add a new user account to an EC2 instance (replace new_user with the new account name). It fixes a small number of further security issues found by the 2019 EU-funded HackerOne bug bounty, and a variety of other bugs introduced in 0. So Changing SSH port may help it to reduce the risk. Use ssh port forwarding to tunnel specific TCP connections though the firewall. Simpson, Diffie-Hellman Group Exchange for the Secure Shell (SSH) Transport Layer Protocol, RFC 4419, March 2006. 31 port 36396 [preauth] Lastly I hope the steps from the article to restrict or allow SSH for certain users, groups and hosts in Linux was helpful. Secure Shell or SSH is a protocol which allows users to connect to a remote system using a client-server architecture. edit the line which reads Port 22 so that it now reads your chosen port. 15 You must use the same port number with the host GDB target remote command. d/ssh restart. the print output need to be only 1 port, and it will be nice if the output will be saved as a variable or in same file. Socket is combination of IP address, software Port and protocol. From now on, you will be able to connect via SSH using your newly updated port number. 1) 32 numbers, grouped using colons. It is not a co-incidence. You could. How to Changing the SSH Port for Your Linux Server You can change the default SSH port for your Linux server as an added security measure. Anyone who has managed an SSH service on the Internet, and viewed the logs will be aware of the amount of SSH brute force attempts that take place every hour of every day. In the example below the SSH port. You can absolutely safely edit just the public port to XXXX and leave private port to 22. Later on these captured packets can be analyzed via tcpdump command. By default SSH server listens for connections on port 22. Connection to host. It is a docker container listening on port 2222. Change default SSH port in Linux/CentOS : Change Default SSH Port (CentOS) Change the port used for SSH connections on a CentOS/Fedora/Red Hat system. XX) and SSH2 (SSH version 2. However, changing the default SSH port will stop attacker from making unauthorized access or from many automated attacks and a bit harder to guess on which port SSH is accessible from. Furthermore, you can specify a port and a destination IP to have direct access. It's readily. In Ubuntu (like other Unix-like systems), it was very straight forward to change the default SSH port number by modifying "Port 22" in "/etc/ssh/sshd_config". The main use of the open SSH command is to log into the host. Now the SSH client at ‘work’ will connect to SSH server running at ‘home’ (usually running at port 22) binding port 9001 of ‘work’ to listen for local requests thus creating a SSH tunnel between ‘home’ and ‘work’. Hi, I'm running centos 5. com 25 port [tcp/smtp] succeeded! The port range was specified to limit the search to ports 20 - 30, and is scanned by increasing order. Secure Shell (SSH) allows HostPapa VPS users to log in and manage their server using a command line application, such as Terminal on Mac OS and Linux, or a third-party application like PuTTY on Windows. As examples, DD-WRT router administration, ASUS router hacks, and Raspberry Pi management, all require SSH work. By default for SSH, it will connect to port 22. No changes to SSH daemon is made. SSH Port Forwarding for TCP. By going through 'gw', files can be uploaded to a machine (in this case 'sm') that refuses direct login. However, there are limited implementations customers can deploy in Windows production. local-port is the number of an available port on your Linux system. ssh_config is a system configuration file for OpenSSH which allows you to set options that modify the operation of the linux client programs. SSH Tunnel is a secure connection between two machines and is often is designed in a way I can only access Workstation linux server on SSH port 22. You should already know your destination server, and for basic uses of port forwarding, you can usually use the port numbers in Wikipedia's list of TCP and UDP port numbers. OpenSSH is developed by a few developers of the OpenBSD Project and made available under a BSD-style license. Anyone who has managed an SSH service on the Internet, and viewed the logs will be aware of the amount of SSH brute force attempts that take place every hour of every day. In this guide, we will show you how you can change SSH port number to any desired choice, on your own CentOS 7 server. Verify the SSH TCP port number in the Azure portal by selecting Virtual machines > VM name > Settings > Endpoints. Of course this presumes you have a SSH/SFTP server running on your Vista box. All servers can still use the same number for the RMI port to connect to the client, like 25000, as was the case in our example. How SSH port forwarding works. How to Change SSH Port in Ubuntu 18. So we get only 2^16(2 to the power of 16) ports which are equal to 65536 available ports. Now, you can log into your server through the port 22 and reset the configuration. Also if you changed your SSH port number you can change the default 22 port number to whatever port number you are using for your server. A TCP/IP network connection may be either blocked, dropped, open, or filtered. SSH remoting lets you do basic PowerShell session remoting between Windows and Linux computers. Some Linux distributions like Arch Linux doesn’t include TCP wrappers by default. The same procedure should also work for VMware Workstation 8, 7 and 6. Examples of commands that would need the new port number specified include scp and rsync. Or you can also type the command along with the username of the remote server in the following syntax:. In Linux based operating systems, The default SSH port is 22. In this post I will discuss setting up port forwarding to manage a local linux virtual machine through ssh, with a focus on mirroring the workflow you might follow with a dedicated Linux server. By default SSH server listens for connections on port 22. SSH is configured on what Port Number, by default? How to change the port of SSH?. You can also launch PuTTY from the Windows programs list. Thayer, The Secure Shell (SSH) Public Key File Format, RFC 4716, November 2006. Remote SSH port forwarding is commonly used by employees to open backdoors into the enterprise. Step 3 : Here, you must proceed with adding your desired port. If selinux is enabled, you have to add new port number to selinux configuration because of the fact that selinux allows only 22 port number for ssh connections. Display the contents of the file banner before user login (default: none). I have to find the currently connected port number. In short, Secure SHell, or SHH, allows the secure exchange of data between two computers. So unless you changed the default port number for ssh on the destination server to 21, or you have not installed and started the ssh server (sshd) on the receiving server, you can not use scp to copy files. To guarantee the MikroTik security and to avoid any kind of attack, one of the security configuration is changing the port number of the Winbox. The program SSH (Secure Shell) provides an encrypted channel for logging into another computer over a network, executing commands on a remote computer, and moving files from one computer to another. Rather than have the port number in the URL, you may wish to set up port forwarding so that connections to the default SSH port are forwarded to the port Bitbucket Server is listening on (e. The following steps are necessary for this from a Linux command line: Execute telnet SERVERNAME 80. Reverse SSH Port Forwarding specifies that the given port on the remote server host is to be forwarded to the given host and port on the local side. For the configuration in putty, give the IP address in hostname along with the port number and then select SSH and then finally click on Open. In this guide, we will show you how you can change SSH port number to any desired choice, on your own CentOS 7 server. You would need to fill in the port number where requests will be created (normally SSH port number is 22 by default if the configuration has not changed in the sshd_config file ) and use the private IP address you found above (via the ip a command) of the Ubuntu computer on which the SSH is running. SSH stands for Secure Shell , It is a virtual terminal used to access linux shell on a network. SSH Tutorial for Ubuntu Linux I touched on this topic in my First Day with Ubuntu at the Office post under Accessing Remove File Systems ; however, I thought that this deserved its own topic. But an SSH client also allows you to “tunnel” a port between your local system and a remote SSH server. Connecting to an Alternate SSH Port. Double-click putty. Anyone who has managed an SSH service on the Internet, and viewed the logs will be aware of the amount of SSH brute force attempts that take place every hour of every day. As it is working over network connection and uses TCP it has a default port number which is 22  . One way to enforce the traffic security is to use the SSH by the way of X11 tunnelling or port forwarding. Sometimes, if we have a lot of SSH keys in our ~/. ssh directory on the local machine, there is a possibility ssh-keygen may overwrite them. Use the below command to do so : semanage port -a -t ssh_port_t -p tcp 1234. SSH command is helpful in logging to another host through command-line. Can I only ping an address? For example: [email protected] ~ $ ping onofri. $ ssh -vv -oCiphers =aes128-cbc,3des-cbc,blowfish-cbc $ ssh -vv -oMACs =hmac-md5 If you are testing with the ciphers or MACs that you have removed, you should be getting something like this. Now, you can log into your server through the port 22 and reset the configuration. This is a story I (Tatu Ylonen) haven't told before. The main use of the open SSH command is to log into the host. Protocols such as FTP, POP3, SMTP, HTTP, TELNET, and others can all be forwarded inside this SSH tunnel providing increased security features such as encryption and authentication that may not otherwise be supported. As examples, DD-WRT router administration, ASUS router hacks, and Raspberry Pi management, all require SSH work. Once logged in, drop from a regular user to Root. SSH Tunnel is a secure connection between two machines and is often is designed in a way I can only access Workstation linux server on SSH port 22. pssh is a program for executing ssh in parallel on a number of hosts. I have a Debian Linux distribution. I recommend using a port number higher then 1000. How to check if SSH is running on Linux? Question – I need to check whether SSH (sshd) is running on my Linux machine. Changing the SSH Port for Your Linux Server You can change the default SSH port for your Linux server as an added security measure. How to change default SSH Listening Port. Once the SSH server is installed and active it is time to move to the other system. ssh directory on the local machine, there is a possibility ssh-keygen may overwrite them. SSH_CONNECTION shows the address of the client, the outgoing port on the client, the address of the server and the incoming port on the server. Replace root with your available authenticating user. Warning: Make sure the new SSH port does not conflict with any known or blocked ports. IPv6 addresses can be specified with an alternative syntax: host/port. ssh command assumes the port number 22. Messages: 58. However if you are having any problem with your ssh connection, follow the steps mentioned above and find out which is the default ssh-port used and then try to ssh using that port. There is something weird on port 10000… Maybe I’ll telnet to it and see what it does!” Of course, upon telnetting to it OpenSSH tells them it’s OpenSSH. How to connect from ssh to another host if random port number used instead of "22": #ssh -p e. Any traffic that comes to this port is sent to the SSH server. After restarting the SSHD service, the SSH is going to listen from the new port only. Connecting to a Linux server using ssh is a very common thing to do. source is /opt/backup. An SSH client connects to a Secure Shell server, which allows you to run terminal commands as if you were sitting in front of another computer. Step 5 – Select the Network settings tab and click the check box for Connect through SSH gateway. Tunneling VNC Through SSH and Connecting. Changing SSH Port On Fedora 28. If you are using UFW on a Ubuntu/Debian Linux, type: $ sudo ufw allow 2222/tcp. Save the file, exit the editor and restart the SSH server. If the port setting in the SSH config file has been changed, you’ll need to specify the port. com 80 20 22. SSH or Secure Shell daemon is a network protocol that is used to perform remotely secured log ins to Linux systems via a secured channel through unsecured networks using strong cryptography. SSH command. By default for SSH, it will connect to port 22. Do it now! Having a centralized location that you can use to quickly “jump” to any box saves a whole bunch of time. The SSH daemon running on the target Linux machine forwards this data to the IP address and port number entered in the "Destination field" field of PuTTY. When you mention the correct port number, the connection is established. This is useful in cases where the service you wish to access doesn't run over SSL, or you do not wish to allow public access to it. com -p 22000 password: ***** Not too bad. Provos, and W. This small walkthrough explains how to configure a port forwarding in VMware Workstation 9. This example is for the ssh. Recently there was a need to connect to a SSH server from my C# code. xx 1234 where 1234 is a port number Thank you | The UNIX and Linux Forums. In fact, SSH1 and SSH2 are two entirely different protocols with no compatibility in between. To change it, open up a terminal window. Ssh (login remotely) into the RPi using Mac with the default port first. It's also very secure. ssh/config file as follows: Host example Hostname example. To follow this. Any traffic that comes to this port is sent to the SSH server. Before a secure connection is established the SSH server must be installed on the system to which the connection is to be established. SSH Port Forwarding for TCP. We use SSH to log into our servers, but it actually has a lot of neat tricks it can help us with as well! We'll cover some of them here. Make sure you do not use a port number that is easy to guess, such as 222, 2222 or 22222. If you change the SSH port to a random number, for example, 2569, you will get rid of most of these annoying and sometimes dangerous brute-force attacks. in the dynamic range of 50-65K) is therefore quite effective. Choose a port number on your local machine (e. There are several ways to set up a Virtual Private Network through SSH. conf file only allow local connections or non-SSH traffic is blocked by. Sometimes, if we have a lot of SSH keys in our ~/. In the above scenario I believe we need to forward remote port 3389 requests to the Linux host to port 3389 on the NAT IP address that the guest OS runs under. In this guide, we will explore how you can change your default SSH port and we will also discuss other preventive measures for protecting SSH access on your server. Your network ACL rules must allow inbound and outbound IPv6 traffic. Provos, and W. 72 released. The console switch operates on a hardened Linux system with enhanced security features including Secure Shell (SSH v2), individual port authentication, and HTTPS. Changing the SSH Port for Your Linux Server You can change the default SSH port for your Linux server as an added security measure. As the service of SSH is started, scan it in your kali using nmap:. The login session is encrypted and very secure. The sshd daemon is the process that runs the OpenSSH ssh server. Do it now! Having a centralized location that you can use to quickly “jump” to any box saves a whole bunch of time. This document explains how to set up VNC to show a full desktop session window from a Linux server, on your home PC or laptop, or office desktop PC. Today, in this brief tutorial, we are going to see the easiest and quickest ways to find the port number of a service in Linux operating system. au 2019 — Christchurch, New Zealand 442,453 views 47:18 Host Multiple Web Sites with One Physical Server - Virtual Hosting with Apache - Duration: 14:27. 1:~ In above given example: ssh port number = 2560 (means port number 2560 is used for ssh rather than port no. Edit configuration nano sshd_config uncomment port Port 5199 So, when we try to SSH, we use port number 5199 3. On windows I investigated a number of technologies. Changing SSH Port. With the X11 forwarding configuration in conjunction with an X Windows client with SSH X11 tunneling to allow for the implementation of a UNIX or Linux GUI subsystem run over SSH securely on the same Windows machine host that is the source for the SSH session to the Linux or UNIX remote host:. In this tutorial, we are going to look at using two SSH clients, OpenSSH client and PuTTY, to create a secure SSH tunnel with dynamic port forwarding function. click the “Save” button to save your tunnel configuration. If you are using UFW on a Ubuntu/Debian Linux, type: $ sudo ufw allow 2222/tcp.