Change DHCP and Router IP results in DNS not working

RouterOS Beginner Basics
1

Hi, relatively new to MikroTik and trying to get to grips with them.

I’m using an RB750G running 6.20 currently

For the purposes of this page I’ve run System > Reset Configuration from within Winbox and I’m going into it completely and totally free of any settings other than the default basic script

Great, so my Router has a public IP, a local IP of 192.168.88.1, DHCP scope of 192.168.88.10-192.168.88.254, I have a client connected, it works, DNS is flowing, and things are happy.

First thing I’d like to do is change my DHCP range from 192.168.88.1-192.168.88.254 to 192.168.1.1-192.168.1.254 with the router sitting on an address of 192.168.1.1. I’ll change this from the QuickSet menu and hit apply.

Before it closes, I’ll also click on IP > DHCP server, networks tab, then double click the default configuration and change the address to 192.168.1.0/24, gateway to 192.168.1.1, and DNS server to 192.168.1.1

Hit apply, reconnect to the routerboard, annnnd DNS isn’t working. I can’t see why. I can ping an IP like 8.8.8.8, but I can’t reach it’s name.

What am I missing here?

2

You have probably windows on your computer. In this case it tends to remember old dns server ip and do not remove it when it receives other in DHCP packet. Check it. Reboot of windows may help.

3

Actually this is common across my CentOS box, my windows machine and my Synology NAS. Rebooting had no effect.

Its as though the DNS software component is not ‘listening’ for requests on a new IP, but I can’t find where in the configuration this is.

And just to confirm, I have restarted the router.

Edit: I wanted to add that I have rebooted the Mikrotik in this instance as well with no effect.

4

Check your computer that it is aware of correct dns server. Check the dns settings in router. Check you don’t have any firewall rule that can be blocking it.
Use torch to see that the computer is really asking dns requests.

5

I’ve confirmed that the machines in question do see the correct DNS server and they are making requests.

What’s interesting is if I change things back to the 192.168.88.x subnet, they work again

6

Do you have a firewall rule (probably in the NAT chains) that is redirecting DNS to a specific IP, so as to “capture” other DNS servers and force them to use the router’s DNS proxy?

Is Hotspot running on the router, and if so, is it still running correctly after the IP change?

7

Thanks for your response. Hotspot is not running on the router.

The only NAT rule I have is the masquerade forwarding

8

Can you share your config?

9

i have constant issues with quick set. If you change your subnet range you will need to make the following changes for DNS to work

go to ip - DHCP server - Networks and change DNS server there

go to ip - DNS - static and change IP there

you should be good to go, mayby just restart connected computer or perform ipconfig /renew

10

Get more familiar with RouterOS and the way of configuration and get rid of QuickConfig.

11

I bought recently a RB951.
I wanted to change the IP class of the network LAN that is defautly 192.168.88.x
I configure my new ip classes for the router and the DHCP server. I received the IP that I configured in the DHCP, but i couldnt resolve DNS.

By analyzing more before in the table ARP I always found the IP default IP 192.168.88.1.

After search I realized that the default configuration was still present for the Ip Address and DHCP Server. I modified the values default configuration from IP Address and DHCP server.
And since all work fine.