I keep talking about a smart house inside one apartment, but it doesn't end there, let's make the garage part of a smart house. And the fact that it is located a few kilometers from my house will not hurt us.
This is a translation of my article in Zen. Also, do not forget to read us in other services: Instagram, telegram (RU, EN, DE). Medium, LiveJournal, YouTube.
Part of the question was raised here (RU). I examined my stocks, 4 mikrotik routers and 3 modems were found. 3 pcs of RB941 and 1 pc of RB951 were found. I use the first ones as access points + switch. But the 951 is a serious device, here we already have POE ports and USB, but the price for it is already higher. Now let's talk about modems, these are e1550 and 2 pcs of yota 4g (they are of different generations, one uses a sim card, and the second has a built-in one).
I chose the rb951 and 4g yota of the latest generation (the rb951 has a usb port, and the modem has a built-in sim card).
Now we will combine 2 subnets (home and remote) into one. As in the last article (RU), we will create a user for an incoming connection and activate the L2TP server
Now we will configure the second router. We will set it up as a DHCP client for the modem. To do this, click Add new and select the LTE interface. Then go to PPP, click Add new and select the l2tp client. Fill in the address, username and password.
If everything was done correctly, then the connection will be established. If you configured the bot as here (RU), then you will receive a notification.
If it didn't work, then it probably got into the firewall. Let's create a rule and put it up.
And now we will indicate the routes to the routers. Go to "Interface" → "Interface list" → "Add New" and add our VPN interface to the LAN list. Then go to "IP" → "routes" → "Add New" and write that the addresses 192.168.3. x should be searched for in the address 192.168.0.3
For the second router, we repeat everything, but we will change the rule: 192.168.2.Х should be searched for in the address 192.168.0.1
After that, everything should work, if other settings of the router do not interfere.
And that's all, subscribe, likes, repost... And we will soon be a small lottery ☺.