I want to use my Huawei E3272 USB 4G modem to connect a DD-WRT WiFi router to the internet via a Pi3B+. First question is can it be done?
Initially, I had a 3G USB modem connected to a TP-Link MR3020 3G router that was connected via an Ethernet cable to the internet port on my DD-WRT WiFi router. This gave access to the internet for anything that was WiFi (or Ethernet) connected to the DD-WRT router. I now effectively want to replace the TP-Link 3G router with a Pi3B+.
With the 4G modem connected to the Pi3B+ I get a good 4G internet connection on the Pi3B+. I then used an Ethernet cable to connect the Pi3B+ to the internet port on my router. Unfortunately, there is now no internet connection when WiFi connected to the DD-WRT router.
Does the Pi3B+ automatically allow sharing its internet connection through its Ethernet port?