Connect to virtualbox guest machine from LAN machine?

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Let’s discuss the following scenario

scenario1

you are on a network (corporative or just your house’s LAN) and there is a machine (host)  that has a virtual machine (guest) that you want to reach from another machine on the network (client)

  • all the machines are running CentOS 6.7
  • the guest has the network configured as NAT

the goal is to establish an ssh connection from the client to the guest

the first step is to make sure that the host is can see the guest with this configuration, in order to do this, you need to create a port forward rule in VirtualBox

port-forward

h7iuV

SVmjK

[update]

I was doing this on a CentOS 7 server and I noticed that the listening address was only 127.0.0.1:28001,  this means that the port won’t be available from an outside client 

update

to fix this, just set to 0.0.0.0 the host IP, once you update it you should see 0.0.0.0:XXX

once this is done we will be able to see the guest from the host, we can log within the guest using

ssh -p 2280 vmuser@localhost #127.0.0.1

now we can log into the guest from client performing two ssh connections

1-client->host # ssh amigo@server.com
2-host->guest  # ssh -p 2280 vmuser@localhost #127.0.0.1

twojumps

but this is not cool because we have to provide two different passwords but there is a way in which we can do it just in one step

How we can access the guest bypassing the host?

make sure that on your /etc/ssh/sshd_config you have uncommented/enabled

GatewayPorts yes
AllowTcpForwarding yes

restart your ssh service

sudo service sshd restart

now we can access the guest from any machine on the network that can see the host

ssh -p 2280 vmuser@server.com

tunnel

be aware that you need to enable the port in your firewall if you use ufw you can do

sudo ufw allow 2280/tcp

one important thing to remember is that we are not doing an ssh port forward, when I first was trying to achieve this I thought that would need ssh port forwarding but I was wrong (and I waste 1 day of my life haha) 🙂

another thing is that in this case, I chose NAT because I couldn’t use “bridge” as the network type since I didn’t have a DHCP configured and the IPs were restricted if you are lucky and you can have DHCP, it is easier, there is no need of forwarding anything

 

https://blogs.oracle.com/scoter/networking-in-virtualbox-v2