Hello,

When I have MikroTik (RouterOS v6.47.1) behind a ADSL router (NAT) and a machines are behind that Mikrotik (NAT), how do I correctly set up UPnP?

It would be easy, if the Mikrotik would be directly on the internet, but I don't have experiences in setting up this configuration. I guess the UPnP request to forward ports from the machines has to be first processed by Mikrotik (to create port forward rules from MikroTik to certain machine on LAN) and then propagated up to the ADSL router (to create port forward rules from ADSL router to the mikrotik).

Thanks

See if you can configure the ADSL router in bridge mode,
Then authentication and PPPoE dialup happens from the Mikrotik and this UpNP config will then be a lot simpler

I guess the UPnP request to forward ports from the machines has to be first processed by Mikrotik (to create port forward rules from MikroTik to certain machine on LAN) and then propagated up to the ADSL router (to create port forward rules from ADSL router to the mikrotik).

Mikrotik can't be a uPnP "client", and use uPnP to open some ports on your ADSL router.
It can only open it's own ports, following the request from your LAN, so that scheme won't work.

You need to get rid of double NAT.

Call your ISP if thy can put your ADSL modem in bridge mode. Then you put your username in password in Mikrotik . So the mikrotik can make connection to your ISP.

The modem is very basic ZTE modem with minimal configuration posibilities. Ill try the ISP but doubt that bridge mode or some PPPoE relay would be possible.

If I disable NAT and DHCP on the Mikrotik and let the modem handle it, would it still be possible using other firewall rules and queues on Mikrotik for LAN clients that are connected through it?

Go to cable modem control page and see what's there.

Already tried, as I said, nothing that would help me. Only basic settings like dhcp, firewall, wlan, upnp.. Its a ZTE V1.0.0_ST_T5P5