My lan Ip is 192.168.4.0/24. My At&t gateway is 192.168.1.254 and in passthru mode. What route or firewall rules I need to implement so I can access it from any lan pc? I'm new in this Mikrotk world.
Thanks, got it working with your steps.Add a second IP to your router's WAN interface - if the modem is connected to ether1, for instance:
/ip address add address=192.168.1.253/24 interface=ether1
next add a srcnat rule to access the modem:
/ip firewall nat add chain=srcnat dst-address=192.168.1.254 action=src-nat to-address=192.168.1.253
Note that if your WAN is using static IP / dhcp (not PPPoE - I don't see a PPPoE interface in your screenshots), that this srcnat rule needs to come before any general-purpose masquerade rule on the WAN interface. Just drag the new rule up the list so that it is sooner in the srcnat chain than the main "access the internet" masquerade rule.
done.