Components of the VDE architecture: - VDE switches: virtual counterpart of ethernet switches. - VDE cables: virtual counterpart of a crossed-cable used to connect two switches.

• VDE 2 includes:
• switch management both from console and from a "unix socket terminal"
• VLAN 801.1q almost compatible
• FSTP (fast spanning tree) already incomplete and currently not tested for 802.1d/w/s compatibility. under development. (vde_switch must be compiled with the FSTP flag on)

Using VDE: - All units connected to the VDE see each other as they were on a real ethernet. - A real Linux box can be connected to the VDE using a tap interface (TUNTAP) (packets can be further routed using standard linux methods). - It is possible to join two VDE switches -- also running on different real conputers -- using virtual VDE cables - UML (user-mode-linux) virtual machines can be connected to the VDE - MPS (MIPS emulated machines (c) Morsiani/Davoli) can be connected to the virtual VDE.

Examples of VDE uses: - With VDE it is possible to create a virtual network of UML machines running on several real computer - VDE can be used to create tunnels (even crossing masquerated networks) - VDE can provide mobility support. Changing a VDE cable with another does not affect the communications in place. The new VDE cable can use a completely different path on the real net. VDE supports also multiple concurrent VDE cables between a pair of VDE-switches during the hand-off. This eliminates when possible hich-ups of communications due to hand-offs.