How to SSH from a Host to a Guest VM on your Local Machine

Pre-requirements

• VirtualBox v6

1. Download the Ubuntu 18.04 LTS image,

• Go to https://ubuntu.com/download/desktop,
• Download `Ubuntu 18.04.3 LTS`,
• Save as `ubuntu-18.04.3-desktop-amd64 .iso`

2. Create an Ubuntu VM in VirtualBox

• Open VirtualBox,

• Click the New button,

• Name the VirtualMachine ,
• For Type select Linux,
• For Version select Ubuntu (64-bit),
• Click Continue,

• Increase Memory size to 4096MB,
• Click Continue,

• Create a virtual hard disk now,
• Click Create,

• Select VDI (VirtualBox Disk Image),
• Click Continue,

• Click Continue,

• Click Create,

2. In the Ubuntu VM guest machine, go to Settings:

• Go to Network:
• Go to `Adapter 1` and add port forwarding by:
• Check Enable Network Adapter,
• Attached to: NAT

• Advanced > Click Port Forwarding,
• Add a new Port Forwarding entry,
• For Name enter SSH,
• For Protocol enter TCP,
• For Host IP enter 127.0.0.1,
• For Host Port enter 5679,
• For Guest IP enter 10.0.2.15,
• For Guest Port enter 22,

• Click OK,
• Go to Network:
• Go to `Adapter 2` and add a new adapter:
• Check Enable Network Adapter,
• Attached to: Host-only Adapter
• Name: vboxnet0

• Go to System:
• Under Boot Order check theNetwork option,
• Under the Extended Features check `Enable I/O APIC` ,

• Click OK,

3. Start the Ubuntu VM guest called MyUbuntuVm1, get the guest IP address,

• Select the image MyUbuntuVm1,
• Click Start,
• Select Normal Start,
• Select a virtual optical disk image file that you downloaded as `ubuntu-18.04.3-desktop-amd64.iso`,
• Browse to the `ubuntu-18.04.3-desktop-amd64.iso` file,
• Click Open,
• Click Start,
• Click `Install Ubuntu`,
• Select English(UK) and click Continue,
• Select Minimal Installation and click Continue,
• Select Erase disk and install Ubuntu, and click Install Now,
• Click Continue,
• Set your timezone, e.g. New York,
• Click Continue,
• Add the admin user and click continue,
• The installation will start,
• Click Restart Now when the installation is complete,
• Press ENTER,
• Restart the VM,
• Login with the created user credentials,
• Install the SSH Server,
• Open a Terminal,

$ sudo apt-get install openssh-server
$ sudo service ssh status

• Get the IP address on your VM instance,
• Get the IP address of the VM Guest,

$ ip addr show
...
2: enp0s3: ...
inet 10.0.2.15/24 brd 10.0.2.255 ...
...
3: enp0s8: ...
inet 192.168.99.104/24 brd 192.168.99.255 ...
...

4. On your host, get the host IP address,

• Open a terminal or console window,
• On a Mac, use `ifcongif`,

$ ifconfig
en0: ...
    ...
    inet 192.168.1.3 ...
    ...
vboxnet0: ...
    inet 192.168.99.101 netmask 0xffffff00 broadcast 192.168.99.255
    ...

• Note the discrepancy between the VM Guest IP and the IP address for vboxnet0 retrieved on your VM Host. You can correct this in the next step.
• Power off the VM,
• Confirm to Power Off,

5. Configure Adapter,

• To make sure the vboxnet0 IP address on the local host has the same IP address as the Ubuntu VM guest you found, go to VirtualBox > File > Host Network Manager,

• go to `Configure the Adapter Manually` and set the `IPv4 Address` to the IP address of the Ubuntu VM guest, e.g. change the detected IP value for vboxnet 192.168.99.101 to the actual vboxnet0 you found in the guest VM of 192.168.99.104.

• Click Apply,
• Click Close,
• Start the VM again,

6. Open a terminal on the VM Host, your local machine, and ssh in to the guest,

$ ssh [email protected] -p 5679
[email protected]’s password: ********
Welcome to Ubuntu 18.04.2 LTS (GNU/Linux 4.18.0–15-generic x86_64)
...
Last login: Sun Jul 28 22:00:21 2019 from 10.0.2.2
user1@user1-VirtualBox:~$

• If you get the following warning and error,

$ ssh [email protected] -p 5679
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Offending ECDSA key in /Users/you/.ssh/known_hosts:28ECDSA host key for [127.0.0.1]:5679 has changed and you have requested strict checking.Host key verification failed.

• Edit the file `/Users/you/.ssh/known_hosts` and remove the IP address entry,
• To read more about VirtualBox networking and the VMs IP addresses, read Oracle VM VirtualBox: Networking options and how-to manage them.
• Exit the guest to return to the host terminal,

$ exit
logout
Connection to 127.0.0.1 closed.