Sun Microsystems VERSION 3.1.0_BETA2 User Manual
6 Virtual networking
VirtualBox has limited support for so-called jumbo frames, i.e. networking packets
with more than 1500 bytes of data, provided that you use the Intel card virtualiza-
tion and bridged networking. In other words, jumbo frames are not supported in NAT
mode or with the AMD networking devices; in those cases, jumbo packets will silently
be dropped for both the transmit and the receive direction. Guest operating systems
trying to use this feature will observe this as a packet loss, which may lead to unex-
pected application behavior in the guest. This does not cause problems with guest
operating systems in their default configuration, as jumbo frames need to be explicitly
enabled.
tion and bridged networking. In other words, jumbo frames are not supported in NAT
mode or with the AMD networking devices; in those cases, jumbo packets will silently
be dropped for both the transmit and the receive direction. Guest operating systems
trying to use this feature will observe this as a packet loss, which may lead to unex-
pected application behavior in the guest. This does not cause problems with guest
operating systems in their default configuration, as jumbo frames need to be explicitly
enabled.
6.2 Introduction to networking modes
Each of the eight networking adapters can be separately configured to operate in one
of the following five modes:
of the following five modes:
Not attached
In this mode, VirtualBox reports to the guest that a network card is
present, but that there is no connection – as if no Ethernet cable was plugged
into the card. This way it is possible to “pull” the virtual Ethernet cable and
disrupt the connection, which can be useful to inform a guest operating system
that no network connection is available and enforce a reconfiguration.
into the card. This way it is possible to “pull” the virtual Ethernet cable and
disrupt the connection, which can be useful to inform a guest operating system
that no network connection is available and enforce a reconfiguration.
Network Address Translation (NAT)
If all you want is to browse the Web, download
files and view e-mail inside the guest, then this default mode should be sufficient
for you, and you can safely skip the rest of this section. Please note that the ping
utility does not work over NAT, and that there are certain limitations when using
Windows file sharing (see chapter
for you, and you can safely skip the rest of this section. Please note that the ping
utility does not work over NAT, and that there are certain limitations when using
Windows file sharing (see chapter
, page
for details).
Bridged networking
This is for more advanced networking needs such as network
simulations and running servers in a guest. When enabled, VirtualBox sets up
an additional, software-based network interface on the host to which the virtual
machine is connected.
an additional, software-based network interface on the host to which the virtual
machine is connected.
Internal networking
This can be used to create a different kind of software-based
network which is visible to selected virtual machines, but not to applications
running on the host or to the outside world.
running on the host or to the outside world.
Host-only networking
This can be used to create a network containing the host and
a set of virtual machines, without the need for the host’s physical network in-
terface. Instead, a virtual network interface (similar to a loopback interface) is
created on the host, providing connectivity among virtual machines and the host.
terface. Instead, a virtual network interface (similar to a loopback interface) is
created on the host, providing connectivity among virtual machines and the host.
The following sections describe the available network modes in more detail.
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