Hi, I want install a 3/4G router into my second house far on seaside, this will allow me to reach videocamera and an ESP8266 for send by telegram alarms of local sensors. I would have access to router too, and to ESP for uploading new firmware, I have a Mikrotik router located at a client with public IP so I can create between them a VPN, but this should be used not for all traffic, just for Winbox, ESP webserver and camera webserver too. The main traffic/internet usage of all connected clients (also me by WiFi when I'm living there) shoud use the default route to internet. How can I do it?
I'm thinking about it, VPN may have a static IP, maybe one of the local network of the second router (the one with public IP), and by firewall I can source NAT that IP to the local address? For example:
192.168.88.1 is the local mikrotik
192.168.88.2 is videocamera
192.168.88.3 is ESP
192.168.1.1 is the second router with public IP
192.168.1.254 is the VPN address of the local Mikotik.
I may open from the local network of the second router (and from internet as well, with dstnat) 192.168.1.254:8291 for the local router, 192.168.1.254:80 for the webpage of camera, 192.168.1.254:81 for ESP. Does all this has sense? If yes, I'll buy it ))
EDIT: reading documentation, creating a tunnel, it's suggested to use a /30 subnet with different ip addresses, maybe this can help to avoid forwarding the local layer3 broadcasts, but this may be a problem for natting?
le'ts say I'm using as in the example 172.16.1.1/30 for tunnel, I'll add route on both routers to reach .88.x and .1.x from both sides, fine, but now I want from internet reach the local router from the second one.. on the second one there should be a source nat (if not, the local device will reply to public address using its gateway) but also a destination nat.. as usual, how to combine them?
Another question, the 3G network isn't unlimited, so how much and how often the keepalive packets of tunnel are transmitted? Is it relevant in a month?