I've just bought an RB450G, help needed for a simple project

RouterOS Beginner Basics
1

My RB450G has just arrived.

The task is simple, NAT for a few PCs.
Which are the steps that I should follow?
Do I need to update anything?

statis IP adress + getwas + dns
2

think this is what you need
http://wiki.mikrotik.com/wiki/NAT_Tutorial

3

You need to configure IP addresses (http://wiki.mikrotik.com/wiki/Manual:IP/Address), possibly a DHCP client on your WAN link (http://wiki.mikrotik.com/wiki/Manual:IP/DHCP_Client), possibly a DHCP server on your LAN link (http://wiki.mikrotik.com/wiki/Manual:IP/DHCP_Server) and NAT (http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/NAT#Source_NAT).

Since you’re looking for a simple setup, the wiki should answer all your questions.

4

Thanks, fewi.

Do I need to update anything? firmware/routeros/etc?
I think I’ve read somewhere, a while ago, about a time limited update or something like that.

5

If you feel like upgrading to the latest version, you can. The Wiki has a how-to guide. However, for just a NAT’ing gateway you’re not going to gain anything by doing that. Unless you’re hitting a specific bug the functionality you want is so basic you might as well keep it as is.

6

Is there a period within I have to update?
Or I can update anytime I want?

7

RB450g comes with default configuration:

  • dhcp-client on ether1
  • ether2-ether4 switched together and running dhcp server
  • masquerade on ether1 interface
  • basic firewall rules to protect the router

So for simple task as you described in first post you don’t need to configure anything, just plug the cables in right ports.

8

Thanks for the tip, mrz.

I’ve just connected to the board via WinBox.

The ISP provider that I have forces me to use an application that tries to stop NAT-ing(long story short, they’ll drop it soon due to large number of petitions).
Anyway, the application can be tricked until they’ll drop it:
-the WAN interface of the router has to be set with specific IP/GW/SM/DNS
-the ether2/3/4/5 ports have to use IPs from a specific class, eg. 85. … … …
-TTL has to be increased by 1

9

Another question, what does Bad blocks from System->Resources mean? It says 40.

And another one, how do I increase TTL by 1?
The ISP sends the packets with TTL=1, in order to block some entry level routers.

10

Assuming your ISP is coming in from port ether1:

/ip firewall mangle add chain=prerouting in-interface=ether1 ttl=less-than:2 action=change-ttl new-ttl=increment:1