Is action=masquerade allowed in chain=dstnat?

Masquerading is a method used in network address translation (NAT) that allows multiple devices on a local network to share a single public IP address. This is commonly used for outbound connections where internal addresses need to be hidden from the outside network.

In the context of MikroTik and its firewall rules, masquerading is specifically utilized in the srcnat (source NAT) chain. The process involves changing the source IP address of the outgoing traffic to the public IP address assigned to the router, thus allowing replies to be routed back correctly.

On the other hand, dstnat (destination NAT) is used to translate incoming requests destined for a public IP address to a private IP address within the internal network. The main purpose of dstnat is to direct incoming traffic to the correct internal resources, typically for services hosted on the network, like web servers or FTP servers.

Since masquerading fundamentally modifies the source address for outgoing traffic, it does not apply to the dstnat chain where the focus is on incoming traffic translation. Therefore, the use of action=masquerade in the dstnat chain is not allowed, which makes the correct answer to the question that this action cannot be used in this context.