VPN for the whole network

[RedX]

Consideration of the issue will be on a specific example: TP-Link N300 (WR842N) v5

In fact, the manual is suitable for almost any router that you use, with the exception of some points related to a specific model. Of course, sewing the ancient DIR-300 is stupid (But it is possible).

There are a lot of instructions on the Internet, but not all of them are correct, so I will write everything inside and out. Let's start!

1. It is necessary to reflash the router for OpenWRT.
First of all, I recommend updating the native firmware of the router [System Tools -> Firmware Upgrade] - downloaded from the manufacturer's site.
Next, we look at the site https://openwrt.org/ for the firmware specifically for your model (especially pay attention to the version! [V3, v4, v5, etc.])
In our case, this ishttps://openwrt.org/toh/hwdata/tp-li...k_tl-wr842n_v5 look for the link Firmware OpenWrt Install URL on the page - download and upload it to the router System Tools -> Firmware Upgrade
You will also need Firmware OpenWrt Upgrade URL with this the same page
Further, the router should stop responding to your requests and turn into a brick. This is normal.
You can access it using ssh. For Windows users, PuTTY is required. For Mac \ Linux users - there is a good old terminal.
We connect via Telnet 192.168.1.1:23 and type in the passwd root command, enter the new password twice and exit
Next, we need any SFTP client.
We connect to 192.168.1.1:22 by SCP login - root, the password is the one specified in the previous step.
Fill in the file that was downloaded from the Firmware OpenWrt Upgrade URL to the / tmp folder
Connect to 192.168.1.1:22 via SSH with the same data and enter sysupgrade -n /tmp/ FILE_NAME.bin
We are waiting for when it is done (look at the light bulbs) after you will see that it has rebooted - you're done.
We connect via Telnet 192.168.1.1:23 and type in the passwd root command and again enter the new password twice.
Two more commands to enable the Web muzzle:
/etc/init.d/uhttpd enable
/etc/init.d/uhttpd start
In the browser, drive in 192.168.1.1 login - root, the password is the one that was set.

2. Setting
The first step is to set up your internet connection. This setting depends on the provider, the only thing I would like to focus on is the case when the Internet provides a 4G modem:
To configure it, you need to install some packages (and the required packages may differ from the modem model). In my case, this is Yota.
But since the packets are pulled from the network, the Internet is needed. Therefore, we take the phone and turn on the distribution of wifi. Go to Network-> WiFi and click Search and connect to the desired network.
[Who is out of tune with English - you can roll the Russification package, this is done like this:
Go to System-> Software, click Update List, wait for the download, then look for the luci-i18n-base-ru package
Go to System-> Software, click Update List, wait for the download, look for and install the following packages:
usb-modeswitch
kmod-usb-core
kmod-usb-ehci
kmod-usb-ledtrig-usbport
kmod-usb-net
kmod-usb-net-asix
kmod -usb-net-cdc-ether
kmod-usb-net-rndis
kmod-usb-ohci
kmod-usb-uhci
kmod-usb2
kmod-usb3
libusb-1.0-0
Click the save and reload button, after which a new eth1 interface will appear - this is and there is a modem interface.
Let's create an interface in Network-> Interfaces with DHCP and select eth1 in the interface.
Now the Internet is available.

3. Now the most important thing
Install packages luci-app-openvpn and openvpn-openssl, save and reload. Then the VPN tab will appear in the menu. Go to VPN-> OpenVPN and download the .ovpn file. We start the connection and turn it on. Save and reload. Also send the router to reboot.
All traffic now goes through the VPN.

I also recommend specifying the DNS you need in the connection interface settings, for example Google (8.8.8.8 and 8.8.4.4)