systemd管理网络应用

采用systemd-networkd管理网卡

1. 主网卡eth0的配置文件/etc/systemd/network/20-eth0.network，静态配置时内容示例如下：

[Match]

Name=eth0

[Network]

Address=192.168.10.111/

DNS=8.8.8.8

DNS=8.8.4.4

[Route]

Gateway=192.168.10.1

Metric=

动态配置时内容为：

[Match]

Name=eth0

[Network]

DHCP=yes

[DHCP]

RouteMetric=

1. 无线网卡的配置文件/etc/systemd/network/21-wireless.network，一般设置为动态IP即可，即该文件内容保持不变。

[Match]

Name=wlan0

[Network]

DHCP=yes

[DHCP]

RouteMetric=

无线网卡的应用服务程序为wpa_supplicant，其systemd配置文件为/lib/systemd/system/wpa_supplicant.service，内容如下，保持不变。

[Unit]

Description=WPA supplicant

Before=network.target

[Service]

Type=simple

ExecStart=/sbin/wpa_supplicant -Dnl80211 -iwlan0 -c /etc/wpa_supplicant.conf

ExecReload=/sbin/wpa_supplicant -Dnl80211 -iwlan0 -c /etc/wpa_supplicant.conf

RestartSec=

Restart=on-failure

[Install]

WantedBy=multi-user.target

Alias=dbus-fi.epitest.hostap.WPASupplicant.service

无线网卡上网方式的配置文件为/etc/wpa_supplicant.conf，样例如下：

ctrl_interface=/var/run/wpa_supplicant

update_config=

network={

scan_ssid=

ssid="test"

psk=""

key_mgmt=WPA-PSK

pairwise=CCMP

}

1. pppoe集成到systemd中，需配置文件/etc/ppp/pppoe.conf和/etc/ppp/chap-secrets、/etc/ppp/pap-secrets。

# cat /etc/ppp/pppoe.conf

DEMAND=no

DNSTYPE=SERVER

PEERDNS=yes

DEFAULTROUTE=yes

CONNECT_TIMEOUT=

CONNECT_POLL=

PING="."

CF_BASE=`basename $CONFIG`

PIDFILE="/var/run/$CF_BASE-pppoe.pid"

SYNCHRONOUS=no

CLAMPMSS=

LCP_INTERVAL=

LCP_FAILURE=

PPPOE_TIMEOUT=

FIREWALL=NONE

LINUX_PLUGIN=

PPPOE_EXTRA=""

PPPD_EXTRA=""

ETH="eth0"

USER="test"

# cat /etc/ppp/chap-secrets

"test"    *    ""

# cat /etc/ppp/pap-secrets

"test"    *    ""

systemd服务配置文件/lib/systemd/system/pppoe.service内容如下（保持不变）。

# cat /lib/systemd/system/pppoe.service

[Unit]

Description=PPP over ethernet

After=network-online.target systemd-networkd.service

Wants=network-online.target systemd-networkd.service

[Service]

Type=forking

ExecStart=/usr/sbin/pppoe-start

ExecReload=/usr/sbin/pppoe-stop;/usr/sbin/pppoe-start

ExecStop=-/usr/sbin/pppoe-stop

ExecStopPost=-ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

Restart=on-failure

[Install]

WantedBy=multi-user.target

1. static、dhcp、wifi、pppoe方式的切换操作步骤如下：

1. 网络部分使用前部署

需安装wpa_supplicant应用程序，并设置该应用开机启动。

apt-get install wpasupplicant

systemctl enable wpa_supplicant

修改wpa_supplicant的systemd配置文件/lib/systemd/system/wpa_supplicant.service内容如下（内容保持不变）：

[Unit]

Description=WPA supplicant

Before=network.target

[Service]

Type=simple

ExecStart=/sbin/wpa_supplicant -Dnl80211 -iwlan0 -c /etc/wpa_supplicant.conf

ExecReload=/sbin/wpa_supplicant -Dnl80211 -iwlan0 -c /etc/wpa_supplicant.conf

RestartSec=

Restart=on-failure

[Install]

WantedBy=multi-user.target

Alias=dbus-fi.epitest.hostap.WPASupplicant.service

增加无线网卡的配置文件/etc/systemd/network/21-wireless.network。

[Match]

Name=wlan0

[Network]

DHCP=yes

[DHCP]

RouteMetric=

pppoe部分需要额外配置内核及安装pppoe且增加pppoe服务配置文件。

Device Drivers ->

Network device support ->

<M> ppp(point-to-point protocol) support

<M> PPP BSD-Compress compression

<M> PPP Deflate compression

[*] PPP filtering

<M> PPP MPPE compression (encryption)

[*] PPP multilink support

<M> PPP over Ethernet

<M> PPP support async serial ports

<M> PPP support for sync tty ports

pppoe安装及服务配置文件：

# apt install pppoe

# cat /lib/systemd/system/pppoe.service

[Unit]

Description=PPP over ethernet

After=network-online.target systemd-networkd.service

Wants=network-online.target systemd-networkd.service

[Service]

Type=forking

ExecStart=/usr/sbin/pppoe-start

ExecReload=/usr/sbin/pppoe-stop;/usr/sbin/pppoe-start

ExecStop=-/usr/sbin/pppoe-stop

ExecStopPost=-ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

Restart=on-failure

[Install]

WantedBy=multi-user.target

2) eth0动态上网：

修改/etc/systemd/network/20-eth0.network内容为：

[Match]

Name=eth0

[Network]

DHCP=yes

[DHCP]

RouteMetric=

之后执行如下命令：

systemctl stop pppoe

systemctl restart systemd-networkd

ifconfig wlan0 down

systemctl restart systemd-resolved

ls -al /etc/resolv.conf | grep systmed >/dev/null || ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

3) eth0静态上网：

根据配置的IP、netmask、Gateway、DNS适当修改/etc/systemd/network/20-eth0.network内容。

[Match]

Name=eth0

[Network]

Address=192.168.10.111/

DNS=8.8.8.8

DNS=8.8.4.4

[Route]

Gateway=192.168.10.1

Metric=

之后执行如下命令：

 systemctl stop pppoe

systemctl restart systemd-networkd

ifconfig wlan0 down

systemctl restart systemd-resolved

ls -al /etc/resolv.conf | grep systmed >/dev/null || ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

4) 无线上网：

根据ssid、psk、key_mgmt、pairwise合理修改/etc/wpa_supplicant.conf。

ctrl_interface=/var/run/wpa_supplicant

update_config=

network={

scan_ssid=

ssid="test"

psk=""

key_mgmt=WPA-PSK

pairwise=CCMP

}

之后执行如下命令：

systemctl stop pppoe

systemctl restart systemd-networkd

systemctl restart wpa_supplicant

ifconfig eth0 down

systemctl restart systemd-resolved

ls -al /etc/resolv.conf | grep systmed >/dev/null || ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

5）pppoe上网：

根据用户名和密码合理修改/etc/ppp/pppoe.conf和/etc/ppp/chap-secrets、/etc/ppp/pap-secrets，其中/etc/ppp/pppoe.conf只需要修改用户名及USER。

# cat /etc/ppp/pppoe.conf

DEMAND=no

DNSTYPE=SERVER

PEERDNS=yes

DEFAULTROUTE=yes

CONNECT_TIMEOUT=

CONNECT_POLL=

PING="."

CF_BASE=`basename $CONFIG`

PIDFILE="/var/run/$CF_BASE-pppoe.pid"

SYNCHRONOUS=no

CLAMPMSS=

LCP_INTERVAL=

LCP_FAILURE=

PPPOE_TIMEOUT=

FIREWALL=NONE

LINUX_PLUGIN=

PPPOE_EXTRA=""

PPPD_EXTRA=""

ETH="eth0"

USER="test"

# cat /etc/ppp/chap-secrets

"test"    *    ""

# cat /etc/ppp/pap-secrets

"test"    *    ""

之后运行如下命令：

systemctl restart systemd-networkd

ifconfig wlan0 down

systemctl restart pppoe

ifconfig eth0 0.0.0.0 && route del default; route add default dev ppp0

1. 上网方式切换时间统计

切换方式	切换后成功连通时间
static -> wifi	约8s
dhcp -> wifi	约18s
others	5s内

注：不同网络环境或测试条件下，时间可能有差距。上述测试环境基于北京网络。

1. 上网方式切换后网络连通的测试方法

   上网方式	切换后连通测试方法
   static	Ping网关
   dhcp	可正确获取到动态分配的IP
   wifi	可正确获取到动态分配的IP
   pppoe	有虚拟网卡ppp0且可获取IP

2. 开机启动时网络设计

断电重启或reboot后，不同上网方式网卡配置和路由不同，需要根据上网方式来正确配置系统。

在/etc/wan_way下保存当前上网方式，可取值：static、dhcp、wifi、pppoe，在/etc/rc.local中增加网络初始化脚本/usr/local/bin/init_networking后台执行，以配置不同上网方式的网络。

#!/bin/sh
wan_way=$(cat /etc/certusnet_conf/wan_way)

case $wan_way in

"dhcp" | "static" )

ifconfig wlan0 down

ls -al /etc/resolv.conf | grep systmed >/dev/null || ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

echo "dhcp or static"

;;

"wifi")

ifconfig eth0 down

ls -al /etc/resolv.conf | grep systmed >/dev/null || ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

echo "wifi"

;;

"pppoe")

ifconfig wlan0 down

systemctl restart pppoe

echo "pppoe"

ifconfig eth0 0.0.0.0

num=

while [ $num -lt  ]

do

num=$(($num+))

pppoe-status | grep -w inet >/dev/null && {

echo "pppoe success after $num *10s"

num=

}

done

sleep 

route del default ; route add default dev ppp0

;;

*)

echo "not dhcp, static, pppoe or wifi"

;;

esac

exit 

1. 目前测试发现问题

采用DHCP方式上网，插拔网线时配置其他设备该网关动态IP，此网关不能获取新的IP。

参考：

1. systemd
   的网络管理

2. 树莓派+1个USB有线网卡+1个USB无线网卡做路由器

3. Linux
   From Scratch - Version 7.7-systemd 通用网络配置

4. systemd-networkd
   (Archlinux wiki)

5. Network
   configuration (Archlinux wiki)

6. 第5章
   网络设置（debian
   manuals）