| 知乎专栏 ｜ 多维度架构 |
pi@raspberrypi:~ $ networkctl
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 eth0 ether routable unmanaged
3 wlan0 wlan no-carrier unmanaged
3 links listed.
pi@raspberrypi:~ $ networkctl status
● State: routable
Address: 192.168.0.147 on eth0
fe80::108e:eede:2340:564e on eth0
Gateway: 192.168.0.1 (Tenda Technology Co.,Ltd.Dongguan branch) on eth0
自动连接区域内WIFI
sudo vi /etc/wpa_supplicant/wpa_supplicant.conf
在文件的末尾添加WIFI网络的名称以及密码，将要连接的wifi名称和密码替换即可。
network={
ssid="SSID"
psk="wifi_password"
}
使用sudo wpa_cli reconfigure命令启动连接
pi@raspberrypi:~ $ sudo wpa_cli reconfigure
Selected interface 'wlan0'
OK
准备树莓派 Raspberry Pi 3 B+
eth0 接入本地网络 wlan0 做WiFi热点
首先安装必须的软件，dnsmasq 是 DNS 域名解析服务。udhcpd 是 DHCP 服务，主要功能是为热点动态分配 IP地址。hostapd 是热点服务
sudo apt upgrade sudo apt install dnsmasq hostapd udhcpd
在 /etc/network/interfaces.d/ 目录中创建 wlan0 文件
sudo vim /etc/network/interfaces.d/wlan0 auto wlan0 iface wlan0 inet static address 172.16.0.254 netmask 255.255.255.0
启用 DHCP
sudo vim /etc/default/udhcpd DHCPD_ENABLED="no" 改为 DHCPD_ENABLED="yes"
配置DHCP分配IP地址范围
sudo cp /etc/udhcpd.conf{,.original}
sudo vim /etc/udhcpd.conf
start 172.16.0.20
end 172.16.0.200
interface wlan0
opt dns 172.16.0.254
#opt dns 8.8.8.8 4.4.4.4
option subnet 255.255.255.0
opt router 172.16.0.254
opt wins 172.16.0.254
option dns 114.114.114.114
option domain local
option lease 864000 # 10 days of seconds
start和end是分配IP的起始与结束范围，interface wlan0 是指定 wlan0 接口广播DHCP，这样不会影响 eth0, 注意分配地址必须与wlan0在同一个网段。
opt dns 8.8.8.8 4.4.4.4 使用Google的DNS，如果希望使用 DNSMASQ 需要设置为 172.16.0.254
如果使用 dnsmasq 解析域名，上面的DHCP需要配置 opt dns 172.16.0.254，这样DHCP分配地址的时候DNS被设置为 172.16.0.254。
sudo cp /etc/dnsmasq.conf{,.original}
sudo vim /etc/dnsmasq.conf
interface=wlan0
bind-interfaces
server=8.8.8.8
server=4.4.4.4
server=114.114.114.114
domain-needed
bogus-priv
dhcp-range=172.16.0.20,172.16.0.200,12h
sudo vim /etc/default/hostapd 找到 #DAEMON_CONF= "" 修改为： DAEMON_CONF="/etc/hostapd/hostapd.conf"
创建 /etc/hostapd/hostapd.conf 配置文件
sudo vim /etc/hostapd/hostapd.conf # Basic configuration interface=wlan0 ssid=netkiller channel=1 #bridge=br0 # WPA and WPA2 configuration macaddr_acl=0 auth_algs=1 ignore_broadcast_ssid=0 wpa=3 wpa_passphrase=13113668890 wpa_key_mgmt=WPA-PSK wpa_pairwise=TKIP rsn_pairwise=CCMP # Hardware configuration wmm_enabled=1
开启ipv4转发
sudo vim /etc/sysctl.conf # Uncomment the next line to enable packet forwarding for IPv4 net.ipv4.ip_forward=1
转发规则
sudo iptables -F sudo iptables -X sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
sudo bash -c iptables-save > /etc/iptables.up.rules sudo vim /etc/network/if-pre-up.d/iptables #!/bin/bash /sbin/iptables-restore < /etc/iptables.up.rules sudo chmod 755 /etc/network/if-pre-up.d/iptables
sudo systemctl restart networking sudo systemctl restart udhcpd sudo systemctl restart dnsmasq sudo systemctl restart hostapd
如果 hostapd 启动失败，可以运行下面命令调试
sudo hostapd -d /etc/hostapd/hostapd.conf
日志
$ cat /var/log/syslog | egrep "hostapd|dhcpcd"
执行 iptable 提示如下
pi@raspberrypi:~ $ sudo iptables -L iptables v1.6.0: can't initialize iptables table `filter': Table does not exist (do you need to insmod?) Perhaps iptables or your kernel needs to be upgraded.
解决方案
pi@raspberrypi:~ $ sudo rpi-update