VirtualBox

Changelog

--Apos 20:33, 11 September 2007 (CEST) Encountered some problems with the network inside of windows guest when doing a snapshop. Could not connect to the host machine, but to the internet and all other machines in the network. The next day the problem was gone.

--Apos 18:11, 10 September 2007 (CEST) All tested with ubuntu feisty host machine and VirtualBox version 1.5. The machine is a 2 GHZ AMD Athlon with two network cards.

Motivation

I am not explaining the installation of a guest virtual machine here.

This guide's only purpose is to point out the major pitfalls using

• ubuntu linux host
• a bridged network ( called host interface in vbox )

Installation

Ubuntu Feisty

Most important informations you will find on the excellent download pages at the wiki of Innotec.

Edit the source.list

vim /etc/apt/sources.list

# Virtual Box
deb http://www.virtualbox.org/debian feisty non-free

Get the gpg key from innotec

wget http://www.virtualbox.org/debian/innotek.asc \
&& apt-key add innotek.asc \
&& apt-get update \
&& apt-get install virtualbox

Prepare the user

Each user has to be part of the vboxusers group

gpasswd -a your_username vboxusers

Configuring the network - Prerequisites

Assumptions

Our machine has two network cards: eth0 and eth1.

• eth0 will be used for the bridged network. It connects internal to the brigde.
• eth1 will be left alone. It is e.g. a gigabit network card for the heavier internal network traffic.

Important to know:

• You should understand, that the bridged network (e.g. br0) will completely superseding the original network card (e.g. eth0). This NIC will change to promiscuous mode.
• All settings of the connected physical network card, including ipaddress, routes, gateway setting etc. must be transferred to this bridge's settings. This assures, that the system is reachable from the outside like before.

Virtual network configuration on the ubuntu/debian host

We need - at least - two new devices for bridged networking.

1. The bridge - e.g. br0
2. At least one virtual network card - e.g. tap0

br0 is the name of the bridge. It gets the IP of eth0, but this is just for convenience, it can be configured like any other network card. Eth0 will be internally connected to this software network switch.

tap0 is the name of the virtual network card, that connects internal to br0. It will be used for connection inside of the virtual machine. If you run multiple virtual machines in parallel, you should configure more tap devices and add them to the bridge.

Configure the virtual machines settings for the network adapter:

1. Use host interface networking.
2. The device for the first virtual guest is called tap0.

Configuring the network - Concrete

Additional packages (ubuntu feisty)

Links: the best ..., interesting ..., be careful ....

Install the uml and bridge utilities:

apt-get install uml-utilities bridge-utils

Alter the default way, ubuntu assigns the rights for

vim /etc/network/if-pre-up.d/uml-utilities

#chown root:uml-net /dev/net/tun
chown root:vboxusers /dev/net/tun

Configuration files (ubuntu feisty)

The tap and bridge devices will be configured using the default ubuntu network scripts:

vim /etc/network/interfaces

# this_gigabit_server
auto eth0
 iface eth0 inet static
 address 192.168.0.4
 netmask 255.255.255.0
 up route add another_gigabit_server gw this_gigabit_server eth0
 up route add another_server gw this_gigabit_server eth0

# this_server
auto eth1
iface eth1 inet manual

# tap devices
# - install more if necessary
auto tap0
iface tap0 inet manual
 tunctl_user apos
 uml_proxy_arp this_server
 uml_proxy_ether eth1
  
# bridge
auto br0
iface br0 inet static
 address 192.168.0.3
 netmask 255.255.255.0
 up route add notebook gw this_server br0
 up route add notebook_wlan gw this_server br0
 up route add server_two gw this_gigabit_server br0
 gateway 192.168.0.254
 # bridge_ports eth1 tap0 tap1 tap2 ...
 bridge_ports eth1 tap0
 bridge_maxwait 0

/etc/init.d/networking restart

Filesharing with samba

According to the Ubuntu Starter Guide install samba and feel free to ether connect via network disks or the connection wizard.

For using network disks inside of Windows NT/XP do

net use x: //ip_samba_server/name_of_share /PERSISTENT:yes

inside of a command terminal.

Filesharing with NFS

Is really a mess inside of windows ... You could try cygwin or mingw but the result is not worth the effort.

Microsoft offers a package called Windows Services for Unix. It is a +200MB package really not worth installing - and configuring! I tried several hours on Windows 2000 professional - you have to map your unix usernames to windows ...

My Tip: Simply stay with samba.