[Qemu-discuss] Integrate a VM directly to local Network with LAN-IP (...no Subnet-IP)

[Thomas Luening]

Hallo @ all,

after 3 frustrating days I give up ... I cannot do it without help. I
have successfully managed to create a local VM with the virt-manager
and also headless via SSH to a NonGui-System .... Debian Buster runs on
all systems.

But it was not possbible to me to give the VM a regular LAN-IP, so the
VM is a regular LAN client. The VM works only via NAT and in its own
subnet to connect to the LAN/WAN. The VM shall work as a FTP-Server,
so is has to be connectable from LAN-Clients.

I have read 100e HowTos .... either outdated, no longer supported,
faulty, fragmented, deprecated, without a "red line", illogical,
incomprehensible, incompatible because other distribution, and so
on ... that is really a description-disaster ;-)

What is the right Way to create a VM, where the VM is a regular LAN-
Client in Home-Net at the end and get an IPv4 from DSL-Router as any
other physical Client? Thats the way how working my Virtualbox-VMs since
a long time, but now I want to migrate to qemu/kvm.

Because I want to understand this way, I want to do it manual, so I have
disable the defaults:

virsh net-autostart default --disable
virsh net-destroy default

I also don't want do it with netfilter-defaults, because iptables will
be set and there starts a conflict with my nftables-firewall.

That is the Command to start create the VM:

virt-install --connect qemu:///system \
--name vmdeb10 \
--memory 2048 \
--vcpus=2 \
--disk /home/qemu/VMs/vmdeb10.cow2,size=8,format=qcow2 \
--cdrom /Images/firmware-buster-DI-alpha5-amd64-netinst.iso \
--noautoconsole \
--os-type linux \
--os-variant debiantesting \
--hvm \
--graphics vnc,port=5900,listen=0.0.0.0 \
--network=bridge=br0,model=virtio

That is my non-customized bridge-Device

# ip link add br0 type bridge
address@hidden:~

# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group 
default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP 
group default qlen 1000
    link/ether 00:22:33:44:55:66 brd ff:ff:ff:ff:ff:ff
    inet 172.100.1.28/24 brd 172.100.1.255 scope global dynamic enp4s0
       valid_lft 861990sec preferred_lft 861990sec
6: br0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 
1000
    link/ether 9e:3f:cc:dd:cc:06 brd ff:ff:ff:ff:ff:ff

I dont use a network-manager, no /etc/init.d/networking. I start my
networking sometimes with address@hidden, some machines with systemd-networkd
and some maschines with my own NWM with iproute2-Commands directly.

My preferred way is iproute-commands, because I can start/set all what is
needed really easy in booting-time with a systemd-service-unit. What I
have to do, so that it will working? I hope, anyone can help me.

BTW: of course, I have tried this with the default bridge networksettings too,
but the Debian installer "dies" at looking for the mirror, in other words, no
network at this point.

Thank you in advance and best regards
Tom