Create a new Network Interface Card and connect it to VLAN n (n = 0 is the default). The NIC is an e1000 by default on the PC target. Optionally, the MAC address can be changed to mac, the device address set to addr (PCI cards only), and a name can be assigned for use in monitor commands. Optionally, for PCI cards, you can specify the number v of MSI-X vectors that the card should have; this option currently only affects virtio cards; set v = 0 to disable MSI-X. If no -net option is specified, a single NIC is created. QEMU can emulate several different models of network card. Valid values for type are virtio, i82551, i82557b, i82559er, ne2k_pci, ne2k_isa, pcnet, rtl8139, e1000, smc91c111, lance and mcf_fec. Not all devices are supported on all targets. Use -net nic,model=? for a list of available devices for your target.
-net user[,option][,option][,...]
Use the user mode network stack which requires no administrator privilege to run. Valid options are:
vlan=n
Connect user mode stack to VLAN n (n = 0 is the default).
name=name
Assign symbolic name for use in monitor commands.
net=addr[/mask]
Set IP network address the guest will see. Optionally specify the netmask, either in the form a.b.c.d or as number of valid top-most bits. Default is 10.0.2.0/24.
host=addr
Specify the guest-visible address of the host. Default is the 2nd IP in the guest network, i.e. x.x.x.2.
restrict=on|off (게스트 OS 네트워크 격리옵션)
If this option is enabled, the guest will be isolated, i.e. it will not be able to contact the host and no guest IP packets will be routed over the host to the outside. This option does not affect any explicitly set forwarding rules.
hostname=name
Specifies the client hostname reported by the builtin DHCP server.
dhcpstart=addr
Specify the first of the 16 IPs the built-in DHCP server can assign. Default is the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.
dns=addr
Specify the guest-visible address of the virtual nameserver. The address must be different from the host address. Default is the 3rd IP in the guest network, i.e. x.x.x.3.
tftp=dir
When using the user mode network stack, activate a built-in TFTP server. The files in dir will be exposed as the root of a TFTP server. The TFTP client on the guest must be configured in binary mode (use the command bin of the Unix TFTP client).
bootfile=file
When using the user mode network stack, broadcast file as the BOOTP filename. In conjunction with tftp, this can be used to network boot a guest from a local directory.
Example (using pxelinux):
qemu -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
smb=dir[,smbserver=addr]
When using the user mode network stack, activate a built-in SMB server so that Windows OSes can access to the host files in dir transparently. The IP address of the SMB server can be set to addr. By default the 4th IP in the guest network is used, i.e. x.x.x.4.
In the guest Windows OS, the line:
10.0.2.4 smbserver
must be added in the file C:\WINDOWS\LMHOSTS (for windows 9x/Me) or C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS (Windows NT/2000).
Then dir can be accessed in \smbserver\qemu.
Note that a SAMBA server must be installed on the host OS. QEMU was tested successfully with smbd versions from Red Hat 9, Fedora Core 3 and OpenSUSE 11.x.
Redirect incoming TCP or UDP connections to the host port hostport to the guest IP address guestaddr on guest port guestport. If guestaddr is not specified, its value is x.x.x.15 (default first address given by the built-in DHCP server). By specifying hostaddr, the rule can be bound to a specific host interface. If no connection type is set, TCP is used. This option can be given multiple times.
For example, to redirect host X11 connection from screen 1 to guest screen 0, use the following:
# on the host
qemu -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
# this host xterm should open in the guest X11 server
xterm -display :1
To redirect telnet connections from host port 5555 to telnet port on the guest, use the following:
# on the host
qemu -net user,hostfwd=tcp::5555-:23 [...]
telnet localhost 5555
Then when you use on the host telnet localhost 5555, you connect to the guest telnet server.
guestfwd=[tcp]:server:port-dev
Forward guest TCP connections to the IP address server on port port to the character device dev. This option can be given multiple times.
Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still processed and applied to -net user. Mixing them with the new configuration syntax gives undefined results. Their use for new applications is discouraged as they will be removed from future versions.
Connect the host TAP network interface name to VLAN n.
Use the network script file to configure it and the network script dfile to deconfigure it. If name is not provided, the OS automatically provides one. The default network configure script is /etc/qemu-ifup and the default network deconfigure script is /etc/qemu-ifdown. Use script=no or downscript=no to disable script execution.
If running QEMU as an unprivileged user, use the network helper helper to configure the TAP interface. The default network helper executable is /usr/local/libexec/qemu-bridge-helper.
fd=h can be used to specify the handle of an already opened host TAP interface.
Examples:
#launch a QEMU instance with the default network script
qemu linux.img -net nic -net tap
#launch a QEMU instance with two NICs, each one connected
#to a TAP device
qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
-net nic,vlan=1 -net tap,vlan=1,ifname=tap1
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
qemu linux.img -net nic -net tap,"helper=/usr/local/libexec/qemu-bridge-helper"
Connect a host TAP network interface to a host bridge device.
Use the network helper helper to configure the TAP interface and attach it to the bridge. The default network helper executable is /usr/local/libexec/qemu-bridge-helper and the default bridge device is br0.
Examples:
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
qemu linux.img -net bridge -net nic,model=virtio
#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge qemubr0
qemu linux.img -net bridge,br=qemubr0 -net nic,model=virtio
Connect the VLAN n to a remote VLAN in another QEMU virtual machine using a TCP socket connection. If listen is specified, QEMU waits for incoming connections on port (host is optional). connect is used to connect to another QEMU instance using the listen option. fd=h specifies an already opened TCP socket.
Example:
# launch a first QEMU instance
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
Create a VLAN n shared with another QEMU virtual machines using a UDP multicast socket, effectively making a bus for every QEMU with same multicast address maddr and port. NOTES:
Several QEMU can be running on different hosts and share same bus (assuming correct multicast setup for these hosts).
Connect VLAN n to PORT n of a vde switch running on host and listening for incoming connections on socketpath. Use GROUP groupname and MODE octalmode to change default ownership and permissions for communication port. This option is only available if QEMU has been compiled with vde support enabled.
Dump network traffic on VLAN n to file file (qemu-vlan0.pcap by default). At most len bytes (64k by default) per packet are stored. The file format is libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
-net none
Indicate that no network devices should be configured. It is used to override the default configuration (-net nic -net user) which is activated if no -net options are provided.
