QEMU net with tap
what we need
- qemu & disk image
- kernel module tun
- kernel configure with BRIDGE support
- tools
sudo apt install bridge-utilssudo apt install uml-utilities
what to do
-
enable tun
sudo modprobe tun
- create bridge
sudo brctl addbr virbr0sudo brctl stp virbr0 on
-
create tap
sudo ip tuntap add dev tap0 mode tapsudo ip link set tap0 up
-
link tap with bridge
sudo brctl addif virbr0 tap0
-
configure
sudo ifconfig virbr0 192.168.122.1sudo ifconfig tap0 192.168.122.100
-
result
brctl show
$ btctl show bridge name bridge id STP enabled interfaces virbr0 8000.52540011a6ac yes tap0
run QEMU with tap
-net nic,model=rtl8139-
-net tap,ifname=tap0,script=no - shutdown the firewall
theory
+---------+---------+
| Physical Eth | real hardware
+---------+---------+
| ---------------------------
+------+------+
| Net Driver |
+------+------+
|
+------+------+
| Host System |
+------+------+
|
+-----+-----+ host linux
| Virtual |
| Bridge |
+--+-----+--+
| |
+---------+ +---------+
| |
+----------+----------+ +----------+----------+
| Virtual Eth (tap0) | | Virtual Eth (tap1) |
+----------+----------+ +----------+----------+
| | ---------------------------
+----------+----------+ +----------+----------+
| Simluated Eth0 | | Simulated Eth1 | simulated hardware
+----------+----------+ +----------+----------+ by QEMU
| | ----------------------------
+-------+-------+ +-------+-------+
| Net Driver | | Net Driver |
+-------+-------+ +-------+-------+
| | guest linux
+-------+-------+ +-------+-------+
| Guest System1 | | Guest System2 |
+---------------+ +---------------+