Accessing the guest OS from the host using VirtualBox

To be able to access the guest OS via ssh fro the host, type the following on the host

$ VBoxManage setextradata Centos\ 5.3\ x86\ bis "VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/HostPort" 3333
 $ VBoxManage setextradata Centos\ 5.3\ x86\ bis "VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/GuestPort" 22
$ VBoxManage setextradata Centos\ 5.3\ x86\ bis "VBoxInternal/Devices/pcnet/0/LUN#0/Config/SSH/Protocol" TCP

(SSH is just a string, you can type anything really). Then you can login to the guest OS by typing this on the host:

$ ssh -p 2222 -X root@localhost

note the same principle applies to other services, example for httpd:

$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/HostPort" 8888
$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/GuestPort" 80
$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/Protocol" TCP

then you can point the host browser to http://localhost:8888. Note that you can’t use a host port lower than 1024 without running VirtualBox with escalated privileges.

To see settings use:

$ VBoxManage getextradata guestname enumerate

To clear a setting (by giving it a clear value) use:

$ VBoxManage setextradata "VBoxInternal/Devices/pcnet/0/LUN#0/Config/ssh/GuestPort"