Need help with IP@ and DHCP

RouterOS Beginner Basics
1

I’m still configuring my network. At least the RB1200 is now routing traffic.
Still I do not understand why I must use NAT that the router routes the traffic, but fine I can stay with that.

My question is if Ihave 3 subnetworks and I’m using the same network (10.10.1.0/24) can I configure that on 3 interfaces of the RB?
Will these 3 ports than be switched or bridged together?
Should I use that or should I use 3 different networks to seperate the traffic?

DHCP: I have now 1 DHCP instance for these 3 networks. Is that a good way to do it?

Thnak you

2

I am not sure what the reference is to having to use NAT - RouterOS can NAT or not as the situation requires.

If you want 3 interfaces on the same subnet use the switch function on the RB1200. See the information on switch chip features at the link below:

http://wiki.mikrotik.com/wiki/Manual:Switch_Chip_Features

3

Ok, I have seperated the ports with different netowrks. Fine

Still I have the problem with NAT. If I deactivate the FW rule for NAT than no traffic is going from/to the Gateway. Do I need to keep the rule active and change the action part from masquerade to something like (accept or passthrought)?
Thank you for your help.

4

You may be referencing info on an earlier thread that I have not seen. If you have private IPs on your LAN then those cannot be routed on the public internet thus you need to NAT that traffic to originate from a publicly routable IP number.

5

My Gateway (ADSL modem) is per default performing NAT.
I do not need NAT on the RB, which is directly behind the gateway.

6

It sounds as if your routerboard is issuing its own IPs. If you want to simply use the firewall & DHCP capabilities of the ADSL modem then you could do so by using the routerboard as a switch/bridge unit in which case there would be no additional NAT required.

The other possibility is to fully use the RB2011 as a firewall etc. and put the ADSL modem into bridge mode - if that is possible.

7

I will check if I can put the modem top bridge mode, I don’t think so.
I need the router because I want to seperate different networks.
Simply I do not want to use NAT on the RB again.
How to configure that?

8

I will check if I can put the modem top bridge mode, I don’t think so.
I need the router because I want to seperate different networks.
Simply I do not want to use NAT on the RB again.
How to configure that?

9

If the “different networks” are not passing traffic via the ADSL modem you do not need to NAT them. If they are passing traffic via the ADSL modem it needs to be NATed to a range that the ADSL modem understands.