Hello friends
I would like help to understand how RouterOS treats packets in a CCR that has only NAT and Fasttrackk.
Scenario: a CCR with 2 ports. The first port is connected to user with private IP 100.64.10.10. The second port is connected to the internet.
On the CCR there is a NAT (chain=srcnat src.address=100.64.10.10 action=srcnat to-address=X.Y.X.Y) and FastTrack is enabled.
Note that I didn't enter any "Out. Interface" in the NAT configuration.
When the 1st packet from USER arrives via SFP2, the packet goes through the NAT rule and is tagged, right?! So the next packet from USER and from the same connection no longer needs to pass the NAT rule, right?
Question 1: Will the packet coming from the internet (entering the SFP1 port) pass the NAT rule as well (I know the MATCH won't happen, because the src-address doesn't match)?
Or will a packet coming from the internet be identified as belonging to a connection that is already open and thus will not pass through the NAT rule?
Question 2: Would there be any processing gain when informing the output port (SFP1) in the NAT rule? After all, packets that are coming from the internet will definitely not pass the NAT rule.