vde_plug - Virtual Distributed Ethernet plug (two plugs creates a
vde cable)
vde_plug [ -p portnum ] [ -g
group ] [ -m octal-mode ] [ socketdir ]
A vde_plug is a plug to be connected into a VDE switch. All
the data that is catched by the plug is written in its stdout and everything
from stdin is injected in the switch.
This tool has been designed to be used together with dpipe
(1) to interconnect a second vde_plug to another switch, working as a
virtual ethernet crossed cable between the two switches.
The command
dpipe vde_plug = vde_plug /tmp/vde2.ctl
connects two local switches: the former is using the standard control socket
/tmp/vde.ctl while the latter is using /tmp/vde2.ctl.
The command
dpipe vde_plug = ssh remote.machine.org vde_plug
connects two remote switches. If the two vde_switches run as daemon and they are
connected to tap interfaces a level 2 encrypted tunnel is established.
vde_plug can also be established as a login shell for users. The
following command works as in the previous example
dpipe vde_plug = ssh vdeuser@remote.machine.org vde_plug
where vdeuser is the user with vde_plug as standard shell. All the remote
accesses are logged by syslog at the beginning and at the end of each session.
Attempt to login without the command vde_plug at the end or trying to execute
something else are blocked and the attempt is logged into syslog.
- -p portnum
- It is possible to decide which port of the switch to use. When this option
is not specified the switch assigns the first available unused port (if
any). It is possible to connect several cables in the same switch port: in
this way all this cables work concurrently. It means that packet can
result as duplicate but no ARP table loops are generated. Is useful when
vde is used for mobility. Several physical interfaces can be used at a
time during handoffs to prevent hichups in connectivity.
- -g group
- group ownership of the communication socket. For security when more want
to share a switch it is better to use a unix group to own the comm sockets
so that the network traffic cannot be sniffed.
- -m octal-mode
- octal chmod like permissions for the comm sockets
- socketdir
- (This option can be also set as: -sock socketdir ) specify
the directory which contains the UNIX socket to be used by local programs
for joining the VDE. The default value is "/tmp/vde.ctl", which
corresponds to the socket "/tmp/vde.ctl/ctl" (or
/var/run/vde.ctl when the vde_switch runs as a shared daemon). It is
possible for users to redefine their default switch as
".vde-2/stdsock" in their home directory. If exist, this
directory (or symbolic link to the actual directory) is used as the
default value for the user.
Virtual Distributed Ethernet is not related in any way with
www.vde.com ("Verband der Elektrotechnik, Elektronik und
Informationstechnik" i.e. the German "Association for Electrical,
Electronic & Information Technologies").
VDE is a project by Renzo Davoli <renzo@cs.unibo.it>