Configure dual-nic in ubuntu for DHCP + NAT

The broadband service provider at home is very strange. It seems that the network is disconnected after several minutes of using the route to access the Internet. This problem does not occur when the gateway accesses the Internet using the dual network card. the role of this antique machine is to be a gateway. Now it is changed to Ubuntu, And the gateway and dhcp should also be added. internet sharing in ubuntu is not as convenient as in windows, but it is not very troublesome. It can be solved after you check it online. I am a lazy and a cainiao at ubuntulinux, so I try to avoid manual settings

The broadband service provider at home is very strange. It seems that the network is disconnected after several minutes of using the route to access the Internet. This problem does not occur when the gateway accesses the Internet using the dual network card. the role of this antique machine is to be a gateway. Now it is changed to Ubuntu, And the gateway and dhcp should also be added. internet sharing in ubuntu is not as convenient as in windows, but it is not very troublesome. It can be solved after you check it online.

I am a lazy and ubuntu linux cainiao, so I try to avoid manual configuration files, such as DHCP and iptables.

First solve the DHCP problem, use the new software package manager to download and install the dhcp3-server and GDHCPD. Then in GDHCPD set DHCP for the NIC, subnet mask, network segment, the gateway can be.

Then solve the NAT problem. I had a headache for configuring iptables. I can see the following article to solve it successfully.