一、虚拟网卡

1、虚拟网卡驱动

2、添加网卡

[root@martin-host ~]# virsh attach-interface vm01_centos79 --type network --model virtio --source default --persistent 
Interface attached successfully[root@martin-host ~]# 
[root@martin-host ~]# virsh domiflist vm01_centos79 
Interface  Type       Source     Model       MAC
-------------------------------------------------------
vnet0      network    default    virtio      52:54:00:3f:99:0c
vnet2      network    default    virtio      52:54:00:92:c5:6b
vnet3      network    default    virtio      52:54:00:01:8d:f7

3、删除网卡

[root@martin-host ~]# virsh detach-interface vm01_centos79 --type network --mac 52:54:00:92:c5:6b --persistent
Interface detached successfully[root@martin-host ~]# virsh domiflist vm01_centos79 
Interface  Type       Source     Model       MAC
-------------------------------------------------------
vnet0      network    default    virtio      52:54:00:3f:99:0c

二、虚拟网络

虚拟网络，相当于现实生活的交换机
NAT模式
桥接模式
隔离模式

1、NAT模式

虚拟网络相当于私网、外界真实网络相当于公网

1.1 SNAT

关注：网关、路由、snat规则

1.2 DNAT 端口映射

[root@martin-host ~]# iptables -t nat -I PREROUTING -d 192.168.140.200 -p tcp --dport 80 -j DNAT --to-destination 192.168.122.101:80[root@martin-host ~]# iptables -t nat -I PREROUTING -d 192.168.140.200 -p tcp --dport 55555 -j DNAT --to-destination 192.168.122.101:22

2、桥接bridge模式

前提条件:
1、物理机的地址必须静态地址
2、物理机关闭NetworkManager服务

[root@martin-host ~]# virsh iface-bridge ens33 br1 
Created bridge br1 with attached device ens33
Bridge interface br1 started

[root@martin-host ~]# ip addr show br1
20: br1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000link/ether 00:0c:29:9d:98:f6 brd ff:ff:ff:ff:ff:ffinet 192.168.140.200/24 brd 192.168.140.255 scope global br1valid_lft forever preferred_lft foreverinet6 fe80::20c:29ff:fe9d:98f6/64 scope link valid_lft forever preferred_lft forever[root@martin-host ~]# ip addr show ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br1 state UP group default qlen 1000link/ether 00:0c:29:9d:98:f6 brd ff:ff:ff:ff:ff:ff

[root@martin-host network-scripts]# cat ifcfg-br1 
DEVICE="br1"
ONBOOT="yes"
TYPE="Bridge"
BOOTPROTO="none"
IPADDR="192.168.140.200"
NETMASK="255.255.255.0"
GATEWAY="192.168.140.2"
STP="on"
DELAY="0"
[root@martin-host network-scripts]# cat ifcfg-ens33 
DEVICE="ens33"
ONBOOT="yes"
BRIDGE="br1"