Mikrotik. GRE-туннель

Поднимаем tun-интерфейс на Debian

auto tun0
iface tun0 inet static
        address 10.101.0.1
        netmask 255.255.255.252
        up ifconfig tun0 multicast
        pre-up iptunnel add tun0 mode gre local 94.130.2.139 remote 83.139.173.154 ttl 225
        pointopoint 10.101.0.2
        post-down iptunnel del tun0