Ubuntu server 24 (Linux) IPtables 双网卡 共享上网NAT 安装配置DHCP

一 开启路由转发功能

sudo vim /etc/sysctl.conf
net.ipv4.ip_forward=1
sudo sysctl -p

二  安装DHCP

#更新软件包列表：
sudo apt update
#安装DHCP服务器
sudo apt install isc-dhcp-server

#修改监听网卡,根据实际修改
sudo vi /etc/default/isc-dhcp-server
INTERFACESv4="enp2s0"
INTERFACESv6="enp2s0"

#修改配置文件
sudo  vi /etc/dhcp/dhcpd.conf
subnet 192.168.50.0 netmask 255.255.255.0 {
   range 192.168.50.30 192.168.50.100; #IP租用地址范围
   option domain-name-servers 192.168.50.1; #dns地址，域名或者IP
   option domain-name "test"; #dns域名
   option routers 192.168.50.1; #网关地址
   option broadcast-address 192.168.50.255; #广播地址
   default-lease-time 6000; #默认租约为6000秒
   max-lease-time 86400; #最大租约为86400s
   log-facility local7;  # 日志级别
}

#启动dhcp服务
sudo systemctl enable isc-dhcp-server
sudo systemctl restart isc-dhcp-server

#查看服务
sudo systemctl status isc-dhcp-server

三  网卡配置

test@test:~$ sudo cat /etc/netplan/50-cloud-init.yaml 
network:
    ethernets:
        enp2s0:
            dhcp4: no
            addresses: [192.168.50.1/24]
              # gateway4: 192.168.50.1
            nameservers:
                addresses: [192.168.50.1]
        enp3s0:
            dhcp4: no
            addresses: [192.168.1.8/24]
            gateway4: 192.168.1.1
            nameservers:
              addresses: [192.168.50.1,114.114.114.114]

    version: 2

#启用
sudo  netplan apply

 四 配置iptables防火墙,共享上网snat

iptables  -t  nat  -A POSTROUTING  -s  192.168.50.0/24 -j SNAT --to-source 192.168.1.8
iptables-save

五 客户端验证,windows 11为例

打开-->设置-->网络和Internet