How to setup static route D-link DSL 2640u Hardware Version C1?

Question

D-Link

Hello.
Came to visit my parents. Here prov distributes the Internet via adsl pppoe. I decided (for my convenience, to set up a tunnel to my office in Moscow time. There is PPTP in the topic settings (L2TP is missing). I set up a PPTP server on Mikrotik in the office.
I set up a tunnel. I registered static routes to the local office network and back. Everything works, but only until you restart dlink.After rebooting, the tunnel rises between the routers, but the static route for the local area networks of the office and home does not work, although it is still in the dlink settings.If you delete the route, re-register it - it works, and again it does not work yet reboot This is the first one.
Second: I noticed that the IP addresses of the hosts of the local network of the parents are connected to the local IP address of the long tunnel, so SIP traffic does not go as it should.
Already changed the firmware. I thought about openwrt, but, as it turned out, on their website they say for this dlink "OpenWRT partially works - device function as wired router, but without ADSL and WiFi.", which accordingly excludes the possibility of configuration for me.
Already covered. :)

Answer 1

It was like this, I replaced it with Zyxel.