FriendlyCore

apt-get install emacs-nox
emacs /etc/netplan/50-cloud-init.yaml:
#我的eth0是wan eth1是LAN，即eth0 dhcp-client ， eth1 dhcp-server
INTERFACESv4="eth1"
INTERFACESv6=""
root@FriendlyELEC:~# cat /etc/netplan/50-cloud-init.yaml
network:
    ethernets:
        eth0:
            dhcp4: true
        eth1:
            dhcp4: false
            addresses: [10.10.0.1/24]
    version: 2

netplan apply

#注意联网
apt-get install isc-dhcp-server #安装dhcp server


emacs /etc/default/isc-dhcp-server:
INTERFACESv4="eth1"

emacs /etc/dhcp/dhcpd.conf:
option domain-name "friendly";
option domain-name-servers  114.114.114.114,8.8.8.8;

default-lease-time 86400;
max-lease-time 86400;
ddns-update-style none;
subnet 10.10.0.0 netmask 255.255.255.0
{
  # Specify the default gateway address                                                                         
  option routers 10.10.0.1;
  # Specify the subnet-mask                                                                                     
  option subnet-mask 255.255.255.0;
  option broadcast-address 10.10.0.255;
  option domain-name-servers 114.114.114.114;
  # Specify the range of leased IP addresses                                                                    
  range 10.10.0.50 10.10.0.200;
}
systemctl start  isc-dhcp-server
systemctl status  isc-dhcp-server
#这个配置有问题看/var/log/syslog 排除问题

#配置ipv4包转发
sysctl -n  net.ipv4.ip_forward #查看是否为1

emacs /etc/sysctl.conf:
net.ipv4.ip_forward=1 # 不是1，修改配置文件
sysctl -p #生效配置
sysctl -n  net.ipv4.ip_forward #查看是否为1

#配置iptables 转发
apt-get install iptables
iptables -t nat -A POSTROUTING -s 10.10.0.0/24 -o eth0 -j MASQUERADE
#此时应该可以通过LAN口访问到公网了
#即ping www.bing.com可以通了
## 由于iptables重启失效，因此使用iptables-save保存配置
iptables-save -c &>> iptables_rules

cat iptables_rules：
## Generated by iptables-save v1.8.4 on Fri Apr  2 19:56:37 2021
*nat
:PREROUTING ACCEPT [24:1577]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
[23:1516] -A POSTROUTING -s 10.10.0.0/24 -o eth0 -j MASQUERADE
COMMIT
## Completed on Fri Apr  2 19:56:37 2021

mv iptables_rules /etc
emacs /etc/rc.local:#设置开机自启动iptables的规则
cd /etc/ && ./start_iptables.sh
exit 0