We have so many great users and have been considering, for a while now, different ways to show our love. Out of those discussions the idea of “Five questions with an OpenDNS user” was born. This will be a recurring post category in the OpenDNS blog. Read and learn.

Richard Hughes
Technical Director
MaxWiFi, London, England

OpenDNS: Please describe your organization, and your role there.

RH: I am the technical director of MaxWiFi. We plan, install and manage temporary WiFi networks for media centres and large events. Recent events have included the PGA European Tour in London, The World Rally Championship in Wales and last year we provided a service to the Royal Marriage of Prince Charles & Lady Camilla Parker Bowles. We shifted over 18Gb of traffic on one day without dropping a single packet with a user base of over 400 media from around the world – all packed into a pub in Windsor.

OpenDNS: How did you first hear about OpenDNS?

RH: I was following a blog trail and came across OpenDNS. We are always looking for find ways to streamline our configs and installs and don’t always like to rely on the ISP services we are given. OpenDNS seemed like such a simple opportunity to speed up searches and to improve the end user services, by providing security from phishing sites and intelligent DNS resolution to take care of spelling mistakes!

OpenDNS: What changes have you noticed on your network since switching to OpenDNS?

RH: It’s always hard to measure network performance, especially when your network is rebuilt and relocated every week. We truly became aware of the improvements at the PGA tour when we had snappers (Photographers) commenting on just how fast the network was. We tested it against another network we had running, that was using local DNS, and there was a perceptible difference. On top of that we saved time on writing the configs and when the ISP DNS servers crashed and took down other network’s on-site we just kept running.

OpenDNS: What advice would you give to others who are considering switching to OpenDNS?

RH: It’s so easy to change and test, we would strongly recommend it. In fact every network we install uses it. I use it in the office and at home. Best of all if you don’t like it swap back – nothing ventured nothing gained!

OpenDNS: What is the strangest thing you’ve ever seen while providing WiFi at an event?

RH: Hmm, my favourite was when an American journalist (never known for being quiet or thoughtful), shouted from the middle of a packed press room, “Your WiFi is C*** – I can’t log on or even see the SSID.” We quickly got over to him and after looking at his laptop for a few minutes explained to him he would need to have a Wireless Card or Centrino in his laptop for WiFi to work!

Second fav was a reporter who was at the Royal Wedding due to broadcast Coast to Coast in the USA. We were impressed by her calm before speaking to such a massive audience. When she came back in she was red faced and explained she had just referred to Lady Camilla as Her Royal Horseness!

Anyway, good luck to you all at OpenDNS and we are looking forward to the London site coming on stream.

I’m doing this blog post in two pieces; a short explanation up top and then a more technical explanation down below. Pick one or read both and learn a bit.

Just the facts

If you want to use OpenDNS nameservers and DNSBLs (DNS real-time Blacklists) on the same server, computer or network, go right ahead. We’ve rolled out a new feature today that allows you to use our much-loved typo-correction service without worrying about blocking email if you’re running a mail server, too. We went ahead and rolled this out as as a system upgrade so there’s no new preference for it. We’ve updated the FAQ entry on mail servers accordingly. Now DNSBL spam prevention and typo-correction go together like peanut butter and jelly (or chocolate… your choice).

If you were previously not using the typo-correction service because you also ran a mail server then head on over to the preferences page and re-enable it.

Talk nerdy to me

DNSBLs carry information about known IP addresses in their zone of DNS. This is often used to combat spam because a mail server can ask a DNSBL “Do you know anything about this IP?” They cleverly use the DNS to make this process quick and seamless. A mail server that gets a request to deliver mail from 192.168.1.2 asks a DNSBL: “Do you know anything about 2.1.168.192.in.yourdnsbl.tld?” and the DNSBL either says “yes I do” or “no I don’t.” The problem is created because when a mail server is using OpenDNS and asks us to correct typos, we interpret the “no I don’t” answer (called RCODE=3 or NXDOMAIN) as a typo that should be forwarded off to our typo-correction service. This causes a mail server to not see the “no I don’t” and instead believe that the answer was “yes I do” which can cause a mail server to block a message thinking it’s from a spam sender. Previously, the only way to fix this was to disable typo correction, one of the benefits of using OpenDNS.

Our solution has been to disable typo-correction for DNSBL-matching requests. What’s a DNSBL-matching request? Any request greater than six labels which has four numerical octets within the IPv4 addressing space for the last-most labels is considered a DNSBL-style request. This wasn’t offered as a preference as turning this off would only lead to confusion, especially with typo-correction enabled.

End of the story? You can get the typo-correction you want and run a mail-server that uses DNSBLs without worrying. Enjoy!

We like hearing from our customers, in just about every way possible. Nothing makes us feel more confident that we’re doing the right things than hearing from you. Also, when we make mistakes (it happens), we want to know about it ASAP so we can fix the problem.

Right now, our listening is mostly via email, IM, comments on our blog, comments on external blogs. But we’d like to make our listening an actual audio experience.

So, give us a call and leave a voicemail at…

+1 (415) 344-3130

This number is not toll-free. Sorry. It’s a San Francisco, California, USA number.

No one will answer; you will hear some instructions, with three basic points:

• Speak clearly.
• If you want a response, be sure to tell us how to reach you (phone, email, otherwise).
• Important – we may use your voicemail comment and name on our website so others can hear what you have to say.

Our inspiration for this experiment

PocketMac Reviews. None of us are PocketMac customers, but listening to these comments, we wish we were!

Note: For the more “traditional” (?) contact methods, go to http://www.opendns.com/contact/.