Configured a NAT without know the destination address

RouterOS Beginner Basics
1

Hello

I’ve a LAN configured with a DHCP server set on ether2 and ports which goes to ether1 - ether5 set with ether2 as master-port. Also, I’ve configured ether6 with a DHCP client and it’s the port which gets the public IPs.

As I don’t know what pulbic IP the ISP will give me and it allways changes,too. I’ve to do a NAT to stablish a connection with every host in the lan and link them with the only IP public.

How I must to do it? because I don’t know the destination address.

/ip firewall nat 
 add chain=src-nat action=srcnat src-address=0.0.0.0 to-address=192.168.200.0/24 out-interface=ether6

But thats not working.

2

/ ip fi nat add chain=src-nat action=masquerade out-interface=ether6
When we have dhcp client for wan, we must use masquerade action !!!

3

Normally you put the ISP on ether1 (WAN) and two is the master of three to six.

4

Thanks very much John. But it’s neccesary a route between the networks, right? this is the code:

# oct/14/2017 13:43:07 by RouterOS 6.37.4
# software id = 818B-XRQ1
#
/interface ethernet
set [ find default-name=ether3 ] master-port=ether2
set [ find default-name=ether4 ] master-port=ether2
set [ find default-name=ether5 ] master-port=ether2
set [ find default-name=ether9 ] master-port=ether6
set [ find default-name=ether1 ] master-port=ether2
/ip pool
add name=dhcp_poolIPv4 ranges=192.168.200.0.2-192.168.200.254
/ip dhcp-server
add address-pool=dhcp_poolIPv4 disabled=no interface=ether2 lease-time=10h name=dhcp_IPv4
/ip address
add address=192.168.200.1/24 interface=ether2 network=192.168.200.0
/ip dhcp-client
add default-route-distance=0 dhcp-options=hostname,clientid disabled=no interface=ether6
/ip dhcp-server network
add address=192.168.200.0/24 dns-server=8.8.8.8 gateway=192.168.200.1
/ip firewall nat
add action=masquerade chain=src-nat out-interface=ether6
/routing rip interface
add interface=ether2 send=v1-2
add interface=ether6 send=v1-2

I don’t get internet access from the LAN 192.168.200.0/24. But in mikrotik console I’ve ping to 8.8.8.8, not from the host that are in the LAN

5

I want to see firewall rules too ! Ping to 8.8.8.8 on lan pc’s?
P.S. You can update the routerboard to final bugfix release of ROS after firmware update of course!
P.P.S. Why you use RIP mostly on LAN?

6

Why should I use firewall rules? The only thing I want to do is a nat and the host OS take care of the firewall. Or it’s necesary to make a nat?

I use rip because the router will learn the network. I can’t make an static route because I don’t know the public network. do I?

7

First, you will not route a public network, so the router will be your border with two sides external and internal. You have a tick in the dhcp client menu to dynamically add your gateway/route/ where the nated traffic is already routed!