Hi,
I have a RB2011, with FW 7.14.2
How should I define firewall rules for port forwarding from a specific IPv6 pool please ? Thanks for help.

You cannot, it requires a NAT64 translator.

Answer from openai:

If you are using a MikroTik RB2011 router and you want to forward traffic from a specific IPv6 pool, you can use NAT64 to translate IPv6 traffic to IPv4. NAT64 is a method that allows IPv6 traffic to be translated into IPv4 traffic, making it easier to connect IPv6-only devices to IPv4 networks.

Here's how you can configure port forwarding using NAT64 on your MikroTik RB2011:

Step 1: Set Up NAT64
Enable NAT64:
Go to the MikroTik RouterOS web interface or WinBox.
In the menu, navigate to /ipv6/ and select nat.
Enable NAT64 by creating a new NAT64 rule.
Create NAT64 Rule:
In the NAT64 configuration, set up a rule to translate IPv6 traffic to IPv4 traffic.
Specify the IPv6 prefix and the corresponding IPv4 pool for NAT64 translation.

Step 2: Define Firewall Rules for Port Forwarding
Specify Source IPv6 Pool:
Define a rule to accept incoming IPv6 traffic from the specific IPv6 pool you want to forward.
In the firewall filter, create a rule with the source IPv6 pool as the source address.
Define Destination:
Set the destination IP and port to the internal IP and port where you want to forward the incoming traffic.
Configure Port Forwarding:
Create a destination NAT rule in the /ipv6/firewall/nat section.
Set the chain to dstnat.
Specify the protocol, destination port, and destination address (internal IP and port).
Save and Apply the Configuration:
Save the changes and apply the configuration to your MikroTik router.

Step 3: Test the Configuration
Verify Connectivity:
Test the connection from the source IPv6 pool to the internal destination IP and port to ensure the port forwarding works.
Monitor Logs:
Check the router's logs to verify that traffic is being forwarded correctly and to monitor for any potential issues.

Security Considerations
Secure the Network: Ensure that your internal network is secure and protected from unauthorized access.
Regular Monitoring: Regularly monitor the router logs and network traffic to ensure everything is running smoothly and securely.
By setting up NAT64 and configuring the necessary firewall rules, you can forward traffic from a specific IPv6 pool to an internal IPv4 network on your MikroTik RB2011 router. Let me know if you need further assistance or have any other specific questions.

Another example on why you shouldn't rely on OpenAI: As @tdw said, a NAT64 translator is needed in order to do that but it is not supported on ROS v7.x or any ROS version in that matter

OK I accept your answer.
I'm not stupid with 66.
Thanks for short result.

You might want to have a look at a public NAT64 services as a workaround: https://nat64.net/public-providers

Thanks,
I'm trying https://nat64.net/

How to create a input and dst_nat please ?
If possible answer with terminal line commands.