Tuesday, August 19, 2008

Setup DNS Mikrotik

ALTERNATIVE PROCEDURE IF YOU WANT TO INPUT A FIXED IP/GATEWAY/DNS SERVER ADDRESS
(instead of using DHCP on the ether1 port)

Caution:
Use care in selecting the DNS SERVER IP address in the setup below. You MUST select an actual DNS server or a router which provides DNS services. Some routers (such as the Hawking FR24) provide a "DNS RELAY" feature on the gateway address which redirects DNS service requests that are sent to the router Gateway Address to some downstream DNS Server. Such "dns relay" service is not always compatible with the Mikrotik system. Other routers (such as the NexLand 800 Turbo and many other router setups) do provide normal DNS Services on the gateway address. In many routers it may depend on user programming.

The Mikrotik router will NOT resolve DNS properly for the Hotspot unless the pointer to a DNS server source points to a "real" DNS Server or a router which actually provides DNS SERVICES on the Gateway address. The result of no DNS service will be that your hotspot login screen will not be loaded when "any URL" is transmitted to the ether2 (Hotspot) port via your browser. This problem can be very confusing to diagnose.

You can test what DNS address you should setup in the Mikrotik unit by running an ip configuration test on a Windows equipped computer connected to your router that you also intend your Mikrotik to use for internet access. Proceed as follows:

b) In your windows computer, in network settings, select tcp/ip properties, and select "obtain an IP address automatically" and "obtain DNS server address automatically". Click OK and exit and reboot if necessary to activate the new settings. Then execute Setup>Run>
then enter <winipcfg>, click OK, (windows 95/98), or <ipconfig>, (or perhaps wntipcfg), click OK, (windows XP/NT/2000), In Windows , you may have to download the winipcfg.exe (or similar) module from the resources folder on the install disk to get this to work. You will get a display such as the image below when you get the ip configuration display and click

Note in this example, the DNS SERVER reported is 192.168.168.1 which IS the same as the Default Gateway and the downstream router (not Mikrotik) IP address. THIS IS NOT ALWAYS SO! The DNS server found by the DHCP operation of your windows computer may be in an entirely different range from the default gateway IP address. Thus, if you use a fixed IP address/Gateway/DNS Server selection, your Mikrotik router DNS Server setup MUST use the DNS Server found by a computer with DHCP Client operating as above. You cannot assume it is the same as your router's default gateway address.

Once you have the downstream router's Gateway address and DNS Server address defined, select an IP address for your Mikrotik unit and proceed as follows. (Here, we are assuming that your Mikrotik System's IP address and mask is 128.1.1.120/255.255.255.0, Gateway of the downstream router is 128.1.1.1 and that the DNS Server's IP address is 207.69.188.186. Make any changes you deem necessary.)
29a)
[admin@MikroTik] interface>
/ip

(Note: The address 128.1.1.120 (below) represents the PUBLIC INTERNET side IP address of the Mikrotik Router. Change to your own suitable address as may be required.)
(All commands must be all in one continuous string (no carriage returns even if the red command characters are shown on multiple lines) when input and followed at the end by a carriage return. Be careful to look for parts of commands on second and even third lines in the listings below. The /24 after the IP address is equivalent to stating that the mask is 255.255.255.0)
29b) [admin@MikroTik] ip> address add address=128.1.1.120/24 comment="TechNet LAN to Internet" interface=ether1
29c) [admin@MikroTik] ip> route add gateway=128.1.1.1
(The following test will locate your public ethernet port . Proceed as follows. You may PING your gateway address (128.1.1.1 in the example) which pinging will occur out the ether1 NIC port. Notes: You may also ping some other address if you wish. You can stop the PING command by entering at any time.) Now we test to see that we are connected to the internet by pinging "some" known IP address such as:)

(Note: This next command normally sets your system up so that all DNS calls go directly to the ISP's DNS servers. If you are behind another router/firewall you could (probably) use the gateway address of your router (as is done in the example) as many do provide DNS service. However, pointing directly to the ISP's DNS servers is usually faster.)
29d) [admin@MikroTik] ip> /ip dns set primary-dns=128.1.1.1 (Change to YOUR ISPs DNS servers. Or- This may be the gateway IP address of a LAN router (as this actually is) which has DNS services. You may be able to change to YOUR ISP's recommended DNS server IP address if permitted by your router and operation will likely be faster.)
29e) [admin@MikroTik] ip> /ip dns set secondary-dns=207.69.188.186 (Add a secondary DNS server if your ISP has one. This example is one of earthlink's DNS servers.)

IF you wish to install a DNS Cache in your Hotspot router so DNS requests will be handled out of the local cache instead of going to the router (or external ISP) each time, enter the following line.
29f) [admin@MikroTik] ip> /ip dns-cache set primary-server=128.1.1.1 (This sets up the dns-cache to access from the LOCAL ROUTER’s DNS server. You may wish to change the above two IP addresses to your ISP’s DNS IP address if permitted by your router. You can also use the
/ip dns-cache set secondary-server=xxx.xxx.xxx.xxx
to set up a secondary DNS-CACHE server if you wish.
)

29g) [admin@MikroTik] ip> dns print
resolve-mode:
remote-dns
primary-dns: 128.1.1.1 (This should be your primary DNS server IP address.)
secondary-dns: 207.69.188.186 (You should setup a secondary-dns server if you have one.)
and then:
29h) [admin@MikroTik] ip> dns-cache print
enabled: no (You get to enable it later when you setup the hotspot.)
primary-server: 128.1.1.1 (This should be your primary DNS server IP address.)
secondary-dns: 0.0.0.0 (You should setup a secondary-dns server (in step #19) if you have one.)
running: no (It will start running if you enable "use DNS CACHE" when you setup the hotspot.)
usage: 0%
entries: 0

taken from http://www.gpsinformation.org/hotspot/fixedether1ipsetup.html

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