mikrotik as gateway/router w/out DHCP or DNS

RouterOS Beginner Basics
1

I’d like to preface this by saying I know next to nothing about networking and am new to routerOS. Any advice/help you provide is greatly appreciated.

I have a client. They have a file server that runs DHCP/DNS.

Before their ISP came in and “upgraded” their hardware the network looked similar to this:

internet → Bridged DSL modem → ddwrt router → server (DHCP/DNS) → internal network

Now it looks like:

internet → DSL modem → server (DHCP/DNS) → internal network

The problem is the new modem is unable to be bridged and doesn’t work with equipment that runs DHCP/DNS. AT&Ts only solution is to put a separate router in the DMZ maintained by their modem. That’s where our Mikrotik comes in.

Currently ether1 is setup to be the WAN port, and it works. Ether2 is setup with one address: 192.168.1.1 and it doesn’t do DHCP or DNS since the client server handles both. If I hookup a laptop with a static IP to ether2, I can ping and trace route any internet IP address without any issues. When I try to ping or tracer route a URL name, it doesn’t resolve and I get an error that says “the connection timed out, no name servers could be reached.”

I’ve used Google DNS, OpenDNS, and the server IP as the Mikrotik DNS.

So I guess my question is can I turn the Mikrotik into a gateway/router that will work with my setup?

I will provide more info if need be.

Thank you.

2

Hello,

I have a client. They have a file server that runs DHCP/DNS.
Before their ISP came in and “upgraded” their hardware the network looked similar to this:

internet → Bridged DSL modem → ddwrt router → server (DHCP/DNS) → internal network

You can now replace the DD-WRT Router by a MikroTik one.
You are able to set up a MikroTik in the internally network as well if you want.

Now it looks like:
internet → DSL modem → server (DHCP/DNS) → internal network

And who is now doing the SPI & NAT part??? Or in plain and shorter words who is
doing the routing job!? The server it selfs? Or another device?
It would be very risky to connect a server and the whole network without any kind of
protection like SPI, NAT, firewall rules or mangle rules to the internet.

The problem is the new modem is unable to be bridged and doesn’t work with equipment that runs DHCP/DNS.

A modem does not to be bridged!!! Only a router with an integrated modem can often be bridged
to run than as a normal modem. Why you want to bridge a modem?

AT&Ts only solution is to put a separate router in the DMZ maintained by their modem. That’s where our Mikrotik comes in.

??? In my poor opinion you should be coming closer or more direct to this point please.
Are this two devices or only one device? As I see it right this is than a router with an internal
modem, is this right? Or comes the MikroTik in as a replacement for the DD-WRT router???

Currently ether1 is setup to be the WAN port, and it works. Ether2 is setup with one address: 192.168.1.1 and it doesn’t do DHCP or DNS since the client server handles both.

Your server can have the gateway address from the Mikrotik router as the DNS IP address.

If I hookup a laptop with a static IP to ether2, I can ping and trace route any internet IP address without any issues. When I try to ping or tracer route a URL name, it doesn’t resolve and I get an error that says “the connection timed out, no name servers could be reached.”

At my servers the DNS entry is filled up with the IP address from the router and at the router
I filled in the DNS1 and DNS2 IP address from the ISP or from Google.

I’ve used Google DNS, OpenDNS, and the server IP as the Mikrotik DNS.
So I guess my question is can I turn the Mikrotik into a gateway/router that will work with my setup?
I will provide more info if need be.

Try to set up at the server the IP address from the router as the DNS server IP address and at the
router the DNS IP address from the ISP or Google. Or, you set up a DMZ this will be also a good idea
for those setups, you could place the server inside the DMZ.