Windows 10: KVM/QEMU users - creating a Network Bridge

Hi folks

Those of you running a Linux host and wanting to run Windows VM's using KVM/QEMU then provided you've got a wired connection you should make a network bridge otherwise your VM will only be able to use NAT with connection limitations.

so ensure net-tools and bridge-utils packages are installed

before starting / creating the vm run this type of script :

ifconfig enp3s0f1 0.0.0.0 <========= change the enp3s0f1 to whatever the name is of your ACTIVE ethernet connection
brctl addbr br0
brctl addif br0 enp3s0f1
dhclient br0
ifconfig

the last ifconfig instruction is to verify bridge is up and has an ip address


now you should have full network access and of course Internet access on your VM.

Here you can see that the bridge (br0) is assigned ip address 192.168.1.16





Now the Windows VM's address is also 192.168.1.16 which is correct and has full connectivity.





(If you only have Wifi -- I haven't yet been able to get a bridge to work (it does on VMWare BTW) - so a get around --USB-->Lan adapter then lan cable into switch and then from switch to wifi extender if you want to avoid long cable runs

I'm working in a shed (what some brits camma "SHOFFICE" -- Shed converted to an office with power heat etc around 100 metres from main router so this solution works really well -- not running 100 metres of LAN cable through a really freezing garden and hard packed ice in winter !!

Cheers
jimbo

:)

 

W10 VM Bridged networking QEMU/KVM (External Switch)

Hi folks

Really SIMPLE way of getting Bridged networking to work in QEMU KVM for proper VM access to rest of your LAN -- equivalent to external switch in HYPER-V

Note you need to do this after re-boot from host each time --you can set a script etc for permanence but as I don't boot the Host very often this works fine.

1) disable any DHCP from the PHYSICAL NIC i.e set the DHCP to disabled

2) enter these commands now : assuming eth0 is your physical NIC you are using

brctl addbr br0
ifconfig eth0 0.0.0.0
brctl addif br0 eth0
dhclient br0

then hey presto you should see your bridge have an ip address (a real one) and the physical nic not have one.





Now in the Windows VM

set the nic to use shared device -- your bridge br0





it will now have a proper IP address on your LAN and this VM will be accessible to everything on your LAN (it can also access the rest of the LAN too)





I spent ages with all the quite complex answers on google and invariably ended up with a total mess --usually BOTH the physical NIC and the bridge (br0) having IP addresses so of course internet didn't work on host and VM !!!!!!!

You need to install dhclient -- ifconfig is also deprecated bit it still is easier for this type of simple command.

Cheers
jimbo

 

Networking on Windows VM from KVM/ QEMU Host via Bridge

Hi folks

For those running Windows VM's on Linux Hosts and want to try the Linux Hypervisor (VMWare and VBOX will run concurrently so you don't even need to power off any running Windows VM's) with decent networking you need to set up a network Bridge (roughly analogous to External Switch in HYPER-V). Otherwise the VM will have access to the Internet only and other parts of your LAN but no host access either way -- either from HOST TO VM or from VM to HOST.

I've assumed you've already installed basic networking and managed to create a Virtual Machine . (You can create the bridge of course before creating the Virtual Machine to test if it's working properly).

1) On the HOST install bridge-utils
2) Create the bridge -- this is done with a simple file in /etc/netctl directory -- my example is kvm-bridge
3) here's the simplest possible file . If you don't like the basic vi editor (ugh !!!!) you can use a wysisyg full screen editor e.g kate that allows root save to root access only folders.

Interface=br0
Connection=bridge
BindsToInterfaces=(enp2s0f1) ===>to a physical device in your system --
IP=dhcp

4) start the bridge : netctl start kvm-bridge

5) automatically start at Host boot

netctl enable kvm-bridge

6) Check via any command if interfaces all working (via ifconfig or any appropriate command). To display the bridge use the command brctl show.

7) In Samba add these two lines to /etc/samba.conf file

bind interfaces only = yes
interfaces = br0 >>>>> Name of your bridge

If you don't do this on the HOST (only) the host will not have any access to any VM's on the LAN whatever host they are attached to -- even those on different physical machines - it will still be able to access physical machines and the Internet though.

8) in the VM config for windows (Easy GUI is to use lib-virt - Virtual machine manager) create virtual network --- specify network source -- etc as shown (for Virtio install the win-virtio drivers otherwise a physical nic card will come up - can be used also but virtio is streets ahead for better for Windows)





9) Now your VM has full network access





10 ) And from the HOST (Hestur) -- the 2nd VM is a VMWare W10 VM on a different host (wulf) not running KVM.





Job Done "Seeemples" !!!


enjoy !!!! ( it's a lot more fun than just starting up VMWare player !!!!!)


Cheers

jimbo

 

qemu-kvm

virt-manager is the gui that can be used to do exactly this.

from the open source project:QEMU is a generic and open source machine emulator and virtualizer.

When used as a machine emulator, QEMU can run OSes and programs made for one machine (e.g. an ARM board) on a different machine (e.g. your own PC). By using dynamic translation, it achieves very good performance.

When used as a virtualizer, QEMU achieves near native performances by executing the guest code directly on the host CPU. QEMU supports virtualization when executing under the Xen hypervisor or using the KVM kernel module in Linux. When using KVM, QEMU can virtualize x86, server and embedded PowerPC, and S390 guests.