+qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
+ -net socket,listen=:1234
+# connect the VLAN 0 of this instance to the VLAN 0
+# of the first instance
+qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
+ -net socket,connect=127.0.0.1:1234
+@end example
+
+@item -net socket[,vlan=n][,fd=h][,mcast=maddr:port]
+
+Create a VLAN @var{n} shared with another QEMU virtual
+machines using a UDP multicast socket, effectively making a bus for
+every QEMU with same multicast address @var{maddr} and @var{port}.
+NOTES:
+@enumerate
+@item
+Several QEMU can be running on different hosts and share same bus (assuming
+correct multicast setup for these hosts).
+@item
+mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
+@url{http://user-mode-linux.sf.net}.
+@item Use @option{fd=h} to specify an already opened UDP multicast socket.
+@end enumerate
+
+Example:
+@example
+# launch one QEMU instance
+qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
+ -net socket,mcast=230.0.0.1:1234
+# launch another QEMU instance on same "bus"
+qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
+ -net socket,mcast=230.0.0.1:1234
+# launch yet another QEMU instance on same "bus"
+qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
+ -net socket,mcast=230.0.0.1:1234
+@end example
+
+Example (User Mode Linux compat.):
+@example
+# launch QEMU instance (note mcast address selected
+# is UML's default)
+qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
+ -net socket,mcast=239.192.168.1:1102
+# launch UML
+/path/to/linux ubd0=/path/to/root_fs eth0=mcast
projects / qemu / blobdiff