Airport Extreme broadcasting wrong DNS server

L

limike28

Registered
I noticed that my macbook and pc were occassionally having an issue where it would take a long time to find a website. A few minutes later it would get through with no issue. This issue happened on a number of websites, and there's no rhyme nor reason.

I think the issue lies in the DNS server that Airport is broadcasting to wifi connections.

My setup: I have a cable modem, which is connected to a 3Com router. The 3Com router is also the DHCP server, and has the DNS server entries set to the 2 from OpenDNS. The ip address of the 3Com router is 192.68.1.1.

Connected to that is an Apple Extreme. This has the ip address 192.168.1.100. This is set up in Bridge mode. I have a MacMini connected to this via ethernet and it experiences no issue. This is also set up to have the DNS Servers listed as the 2 from OpenDNS.

However, during troubleshooting I noticed that on my macbook the first DNS entry (under wifi) is 192.168.1.1. This entry is greyed out and I can not remove it. Does anyone have any ideas what the issue and how I can get the airport extreme to broadcast a correct dns?
 
Did you do the Open DNS in your Mac or on the router? If you do it in the main router in OS X will list the router in light gray as the DNS, that's OK.

Plus just for giggles have you download the DNSChanger Removal Tool and make sure you haven't got the known Trojans by going to some p0rn sites and or download illegal torrents applications.
 
And, in bridged mode, I don't think there is any reason to set DNS servers. You have the DNS servers defined on the router, and if you define them again on the AirPort Extreme, then you have two potential sources for DNS information.

I would think that DNS servers on the Extreme should be left blank, or should be the internal IP address of the router (192.168.1.1)... since the Extreme is simply a "pass-through" for wireless data to the router. It shouldn't be doing any outside DNS resolution -- only the router should.

Also, the AirPort Extreme is broadcasting the correct DNS server -- 192.168.1.1. That's the DNS server that your wireless clients will use -- they will be querying the router to resolve domain names like apple.com and microsoft.com, and the router, in turn, will use OpenDNS servers to resolve them to actual, outside IP addresses. I have a similar network setup (without a bridge -- just wireless router), and all my wireless clients list 192.168.0.1 (the router's internal IP address) as their DNS server -- which is correct. I am then using OpenDNS servers on the router. Everything is resolving correctly -- if I enter a malformed URL or something on a wireless machine, the OpenDNS page for invalid URLs is displayed in the browser window -- proving that the router, is indeed, using OpenDNS for name resolution.
 
ElDiablo, thanks for the explanation. That makes sense.

I due notice a lag at times getting to websites. I am wondering if that's due to the age of the old wired router.

Thanks for the good explanation.
 
Ok, I think I have it straight now. The DNS servers are only listed on my primary router, and all other equipment is pointing to that router for the DNS. It seems to be working pretty well. Thanks for the help.
 
You must log in or register to reply here.
Back
Top