KVM，架设网桥

Question

我不知道如何为KVM创建网络桥。我所做的:我的操作系统:Ubuntu18.04

1. 我安装了桥接器

sudo apt-get install bridge-utils

1. 我修改了文件/etc/netplan/50-cloud-init.yaml。这是内容：

network:
    version: 2
    ethernets:
        eno1:
            addresses: []
            dhcp4: true
        eno2:
            addresses: [192.168.0.101/24]
            gateway4: 192.168.0.1
            dhcp4: false
        enp4s0f0:
            addresses: []
            dhcp4: true
            optional: true
        enp4s0f1:
            addresses: []
            dhcp4: true
            optional: true
        enp5s0f0:
            addresses: []
            dhcp4: true
            optional: true
        enp5s0f1:
            addresses: []
            dhcp4: true
            optional: true

    bridges:
        br0:
            interfaces: [eno2]
            dhcp4: false
            addresses: [192.168.0.100/24]
            gateway4: 192.168.0.1
            nameservers:
                addresses: [192.168.0.1]
            parameters:
                stp: true
                forward-delay: 4

1. 我运行了网络计划申请。一切都完美无缺。现在我看得出来：

3: eno2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br0 state UP group default qlen 1000
    link/ether 78:2b:cb:33:29:3d brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.101/24 brd 192.168.0.255 scope global eno2
       valid_lft forever preferred_lft forever

8: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:43:8d:69 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever

1. 我增加了网络的定义:主机桥

virsh # net-dumpxml host-bridge
<network connections='1'>
  <name>host-bridge</name>
  <uuid>1823e6a7-3a86-4d7f-b612-27c003066faa</uuid>
  <forward mode='bridge'/>
  <bridge name='br0'/>
</network>

1. 然后，我用以下方式安装新vm：

virt-install --name=debian-tutorial4 \
    --vcpus=4 \
    --memory=8192 \
    --cdrom=/vm-images/debian-10.0.0-amd64-netinst.iso \
    --disk size=10,format=raw \
    --os-variant=debian9 \
    --network network=default \
    --network network=host-bridge

1. 当我运行virsh dumpxml debian-tutorial4时，我可以看到：

<interface type='network'>
    <mac address='52:54:00:48:0d:a2'/>
    <source network='default' bridge='virbr0'/>
    <target dev='vnet3'/>
    <model type='virtio'/>
    <alias name='net0'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>
<interface type='bridge'>
    <mac address='52:54:00:ca:51:97'/>
    <source network='host-bridge' bridge='br0'/>
    <target dev='vnet4'/>
    <model type='virtio'/>
    <alias name='net1'/>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</interface>

当我登录到VM并运行ip a时，我可以看到：

daniel@debian4:~$ 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
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:48:0d:a2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.173/24 brd 192.168.122.255 scope global dynamic ens3
       valid_lft 3534sec preferred_lft 3534sec
    inet6 fe80::5054:ff:fe48:da2/64 scope link 
       valid_lft forever preferred_lft forever
3: ens4: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 52:54:00:ca:51:97 brd ff:ff:ff:ff:ff:ff

我需要做什么来连接我的VM到网桥网络？

感谢您的回复。

主机上的接口已打开。

root@smaug:/home/daniel# ip a show br0 up
94: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 82:43:74:4e:8d:c4 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.100/24 brd 192.168.0.255 scope global br0
       valid_lft forever preferred_lft forever
    inet6 fe80::8043:74ff:fe4e:8dc4/64 scope link 
       valid_lft forever preferred_lft forever

从eno2中删除IP

        eno2:
            addresses: []
            dhcp4: false

但我仍然无法在VM上的接口上看到IP。

Answer 1

在主机系统上检查br0接口的状态。应该起来了。

在您的情况下，您应该在来宾系统中配置ens4接口。此接口对应于您的桥接网络。

另外，您不应该在eno2接口上分配任何ip地址，因为它是桥端口接口( br0接口的从接口)。

其他东西似乎配置正确。

Answer 2

终于解决了我的问题：

解决方案：

在主机上一切都很好。这是我安装的Debian的一些问题。

我通过virt查看器登录到那里，然后修改了/etc/network/interfaces：

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-hotplug ens3
iface ens3 inet dhcp

iface ens4 inet static
    address 192.168.0.110/24
    gateway 192.168.0.1

然后向下和向上的接口和重新启动网络

ip link set dev ens3 down
ip link set dev ens4 down
ip link set dev ens3 up
ip link set dev ens4 up

systemctl restart networking

然后重新加载dhcp：

/sbin/dhclient

最后我的VM得到了IP

root@debian4:/home/daniel# 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
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:fa:76:1b brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.71/24 brd 192.168.122.255 scope global dynamic ens3
       valid_lft 3277sec preferred_lft 3277sec
    inet6 fe80::5054:ff:fefa:761b/64 scope link
       valid_lft forever preferred_lft forever
3: ens4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:54:00:71:c1:ed brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.110/24 brd 192.168.0.255 scope global ens4
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fe71:c1ed/64 scope link
       valid_lft forever preferred_lft forever