OpenDNS Shut the Door

So here’s a kind of weird thing I can­not fig­ure out: using OpenDNS on our home router killed my cor­po­rate VPN.

I’ve been a fan of OpenDNS for some time. I do think it’s faster than Com­cast’s DNS servers and it is cer­tain­ly more secure. It’s also pret­ty handy when you just have a typo in a domain name, which I do often. I’ve only ran into one issue where I could­n’t get to a site I was actu­al­ly try­ing to vis­it (and that is weird — just like a part of the inter­net you know should be there is gone).

Until today.

I added the OpenDNS servers on my Apple Air­port Base Sta­tion. It reboot­ed quick­ly and every­thing seemed nor­mal. My Win­dows machine was able to recon­nect to the VPN with no trou­ble. How­ev­er, I could not con­nect to the Microsoft Exchange serv­er nor the Office Com­mu­ni­ca­tor serv­er. The entire rest of the inter­net worked just fine, just those two (high­ly crit­i­cal) items did not work at all.

I should note that I was able to con­nect to the Exchange serv­er via my iPhone or a web brows­er, so it was­n’t down dur­ing this time. Fur­ther, reset­ting the DNS entries on my router cor­rect­ed the prob­lem almost instantly.

I real­ly fail to see how the DNS serv­er could affect con­nect­ing to some­thing over a VPN, but it clear­ly has some issue. So, I’m stuck with Com­casts slow (and pos­si­bly unsafe) DNS servers for now. But, at least I have a VPN!