KVM

Config virtual network connection with bridge mode

摘要

在宿主机为 CentOS 7 的环境中通过KVM配置CentOS 7 虚拟机，使用 Bridge 模式配置网络连接，使虚拟机与宿主机处于同一网络环境中。

Create Brdige

Install Module

CentOS 7 在系统启动时默认加载了桥接模块。使用下面的命令可以判断这个模块是否加载。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
[root@weilu_125 kvms]# modinfo bridge
filename:       /lib/modules/3.10.0-862.el7.x86_64/kernel/net/bridge/bridge.ko.xz
alias:          rtnl-link-bridge
version:        2.3
license:        GPL
retpoline:      Y
rhelversion:    7.5
srcversion:     A0B6183F98024E85CD123C5
depends:        stp,llc
intree:         Y
vermagic:       3.10.0-862.el7.x86_64 SMP mod_unload modversions 
signer:         CentOS Linux kernel signing key
sig_key:        3A:F3:CE:8A:74:69:6E:F1:BD:0F:37:E5:52:62:7B:71:09:E3:2B:96
sig_hashalgo:   sha256

如果这个模块没有加载，可以使用下面的命令进行加载。

1
modprobe --first-time bridge

安装桥接工具：

1
yum install bridge-utils -y

create a network bridge

要创建一个网桥，可以在 /etc/sysconfig/network-scripts/ 目录下创建一个名为 ifcfg-brN 的文件，将其中的 N 替换为数字，比如“0”。

1
vi /etc/sysconfig/network-scripts/ifcfg-br0

将下面的内容放置到这个文件中，对应你的主机环境修改相应配置：

1
2
3
4
5
6
7
8
9
TYPE=Bridge
NAME=br0
DEVICE=br0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.125
GATEWAY=192.168.0.1
NETMASK=255.255.255.0
DNS1=192.168.0.1

创建完网桥之后，需要将网络配置接口挂载到这个网桥上。比如，我这边使用的本机已有的适配器 eno1：

1
vi /etc/sysconfig/network-scripts/ifcfg-eno1

将以下内容放置到该配置文件中：

1
2
3
4
5
6
TYPE=Ethernet
BRIDGE=br0
NAME=eno1
UUID=99244a4d-8cac-4023-9a09-8e50c547cd3a
DEVICE=eno1
ONBOOT=yes

使用如下命令重启网络服务：

1
systemctl restart network

查看网络配置：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
[root@weilu_125 network-scripts]# ifconfig
br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.125  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::329c:23ff:fee1:f0d9  prefixlen 64  scopeid 0x20<link>
        ether 30:9c:23:e1:f0:d9  txqueuelen 1000  (Ethernet)
        RX packets 3503  bytes 599352 (585.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1932  bytes 1004140 (980.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        ether 30:9c:23:e1:f0:d9  txqueuelen 1000  (Ethernet)
        RX packets 510891  bytes 330776497 (315.4 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 285983  bytes 46787578 (44.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 16  memory 0xa1100000-a1120000  

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 13058  bytes 1819263 (1.7 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 13058  bytes 1819263 (1.7 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Config Guest Connection

在虚拟机的设置中，将 Network source 设置为通过刚刚设置的网桥进行连接。
enter image description here

然后修改虚拟机的网络配置：

1
2
3
4
5
6
7
8
9
TYPE=Ethernet
ONBOOT=yes
DEVICE=eth0
BOOTPROTO=static
IPADDR=192.168.0.161
NETMASK=255.255.255.0
BROADCAST=192.168.0.255
GATEWAY=192.168.0.1
DNS1=192.168.0.1

使用如下命令重启网络服务：

1
systemctl restart network

查看网络配置：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
[root@localhost ~]# ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.0.161  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::5054:ff:fe24:c503  prefixlen 64  scopeid 0x20<link>
        ether 52:54:00:24:c5:03  txqueuelen 1000  (Ethernet)
        RX packets 212  bytes 183776 (179.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 186  bytes 18719 (18.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 68  bytes 5912 (5.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 68  bytes 5912 (5.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

test

From Host

1
2
3
4
5
6
7
8
9
[root@weilu_125 network-scripts]# ping 192.168.0.161 -c 3
PING 192.168.0.161 (192.168.0.161) 56(84) bytes of data.
64 bytes from 192.168.0.161: icmp_seq=1 ttl=64 time=0.386 ms
64 bytes from 192.168.0.161: icmp_seq=2 ttl=64 time=0.327 ms
64 bytes from 192.168.0.161: icmp_seq=3 ttl=64 time=0.320 ms

--- 192.168.0.161 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 0.320/0.344/0.386/0.033 ms

From Guest

1
2
3
4
5
6
7
8
9
[root@localhost ~]# ping 192.168.0.125 -c 3
PING 192.168.0.125 (192.168.0.125) 56(84) bytes of data.
64 bytes from 192.168.0.125: icmp_seq=1 ttl=64 time=0.101 ms
64 bytes from 192.168.0.125: icmp_seq=2 ttl=64 time=0.260 ms
64 bytes from 192.168.0.125: icmp_seq=3 ttl=64 time=0.252 ms

--- 192.168.0.125 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 0.101/0.204/0.260/0.074 ms