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To enable above on your MikroTik router, you should drag and drop as #1 item on your NAT list like below:
To allow internal connection to your server directly, you should add NAT rule by IP → Firewall → NAT → Add New
Other references helpful
| Features | Notes |
|---|---|
| SSH Server | default user id: admin default port: 22 |
| Policy Based Routing | https://wiki.mikrotik.com/wiki/Policy_Base_Routing |
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