为主机和虚拟机设置桥梁

Question 1

我仅使用过 networkd 作为渲染器，而没有使用 NetManager，所以我不知道这个答案的价值。

保存/etc/netplan/01-network-manager-all.yaml在某处，这样如果事情不起作用，你可以恢复。

创建/etc/netplan/01-netcfg.yaml（假定网关地址）：

# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    enp4s0:
      dhcp4: no
  bridges:
    br0:
      interfaces: [ enp4s0 ]
      dhcp4: no
      addresses: [192.168.2.15/24]
      gateway4: 192.168.2.1
      nameservers:
        addresses: [1.1.1.1]
      dhcp6: no
      link-local: [ ]
      parameters:
        stp: true
        forward-delay: 4

做：

sudo netplan apply

转到/etc/libvirt/qemu/networks。应该有一个host-bridge.xml文件。保存一份副本：

sudo cp host-bridge.xml host-bridge.xml.original

如果你没有host-bridge.xml文件，我的原文是：

doug@s19:~/config/etc/libvirt/qemu/networks$ cat host-bridge.xml.original
<network>
    <name>host-bridge</name>
    <bridge name='br0'/>
    <forward mode="bridge"/>
</network>

运行以下命令：

virsh net-define host-bridge.xml
virsh net-autostart host-bridge
virsh net-start host-bridge
virsh net-list --all

如果遇到问题并需要撤消，请注意：

virsh net-destroy br0
virsh net-undefine br0

例子：

doug@s19:~/config/etc/libvirt/qemu/networks$ virsh net-list --all
 Name          State    Autostart   Persistent
------------------------------------------------
 host-bridge   active   yes         yes

例子：

doug@s19:~/config/etc/libvirt/qemu/networks$ sudo cat /etc/libvirt/qemu/networks/host-bridge.xml
<!--
WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE
OVERWRITTEN AND LOST. Changes to this xml configuration should be made using:
  virsh net-edit host-bridge
or other application using the libvirt API.
-->

<network>
  <name>host-bridge</name>
  <uuid>d474d859-8448-4055-9fc0-bb0b6cb83c34</uuid>
  <forward mode='bridge'/>
  <bridge name='br0'/>
</network>

现在，修改任何现有的虚拟机以使用桥接器：

注意：可能有一种方法可以使用来完成这一步virt-manager，但是我没有使用它并且不知道如何操作。

使用virsh edit并更改接口定义行以使用桥接而不是当前正在使用的。如下所示：

前：

<interface type='network'>
  <mac address='52:54:00:06:8d:b0'/>
  <source network='default'/>
  <model type='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>

后：

<interface type='bridge'>
  <mac address='52:54:00:06:8d:b0'/>
  <source bridge='br0'/>
  <model type='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>

要创建一个新的虚拟机，取决于你的方法，例如：

virt-install -n serv-jj -r 8192 \
--disk path=/home/doug/vm/serv-jj.img,bus=virtio,size=50 \
-c jammy-live-server-amd64-2022-04-21.iso \
--network bridge=br0,model=virtio,mac=52:54:00:27:1c:6e \
--graphics vnc,listen=0.0.0.0 --noautoconsole -v --vcpus=4 --cpu SandyBridge

运行 3 个虚拟机的示例：

doug@s19:~$ ip addr
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: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br0 state UP group default qlen 1000
    link/ether 3c:7c:3f:0d:99:83 brd ff:ff:ff:ff:ff:ff
3: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 3c:7c:3f:0d:99:83 brd ff:ff:ff:ff:ff:ff
    inet 192.168.111.136/24 brd 192.168.111.255 scope global dynamic br0
       valid_lft 81610sec preferred_lft 81610sec
4: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:22:2f:dc brd ff:ff:ff:ff:ff:ff
5: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:60:ea:3e brd ff:ff:ff:ff:ff:ff
6: vnet2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UNKNOWN group default qlen 1000
    link/ether fe:54:00:60:ea:5e brd ff:ff:ff:ff:ff:ff
doug@s19:~$ networkctl
IDX LINK   TYPE     OPERATIONAL SETUP
  1 lo     loopback carrier     unmanaged
  2 enp3s0 ether    enslaved    configured
  3 br0    bridge   routable    configured
  4 vnet0  ether    carrier     unmanaged
  5 vnet1  ether    carrier     unmanaged
  6 vnet2  ether    carrier     unmanaged
doug@s19:~$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.3c7c3f0d9983       no              enp3s0
                                                        vnet0
                                                        vnet1
                                                        vnet2

本文未涉及：如何在 VM 上设置静态地址 192.168.2.16，因为 VM 被声明为 FreeBSD，而我不知道如何操作。

参考：
https://netplan.io/examples/#configuring-network-bridges
KVM 网络桥分配静态 IP

Answer