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4.2.2.2: The Story Behind a DNS Legend

105 points| martinml | 12 years ago |tummy.com | reply

37 comments

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[+] nodesocket|12 years ago|reply
I noticed very strange but consistent performance behavior from Google Public DNS. Even though a DNS record was cached, the response time was in the range of 20-30ms, which is absolutely horrible. When I switched over to OpenDNS, cached response times dived down to 1ms. Needless to say just made the switch on all the servers to OpenDNS. Can anybody explain this behavior?

Here is the GitHub gist showing the output:

https://gist.github.com/nodesocket/786e3b879f74c7787ca6

[+] remosi|12 years ago|reply
Where in the world are you? Do you have a traceroute to 8.8.8.8?
[+] micro-ram|12 years ago|reply
There are different reasons to use the various dns servers:

Both Google (8.8.8.8 / 8.8.4.4) and OpenDNS (208.67.220.220 / 208.67.222.222) can be troublesome on small networks when trying to reach local LAN devices because they resolve failures to their own search pages. My fallback here is to always try one of the L3 servers (4.2.2.1 - .6)

OpenDNS is my goto when I need filtering. OpenDNS is also great when changing ip addresses on domains because you can clear their public cache and make sure everything is updated and is working immediately. http://www.opendns.com/support/cache/

Google DNS tends to make youtube streaming work much better for me.

Even Comcast has even recently changed their dns to memorable numbers 75.75.75.75 / 75.75.76.76

[+] Ueland|12 years ago|reply
I have neither heard of Google`s DNS servers resolving failures to their own search pages, nor experienced it myself after using it since it`s release.

OpenDNS on the other hand...

[+] axaxs|12 years ago|reply
DNS is for the most part a pass-fail type system. It can in no way make streaming better, unless your ISP is purposely giving wrong addresses for YouTube. Is that common now? It wouldn't surprise me, to be honest..
[+] ghshephard|12 years ago|reply
I've been using 4.2.2.2 on almost daily basis since 2003 - every time I want to see if I'm connected to the Internet, anywhere in the world - that's my canary.

It had never occurred to me to wonder why I was using 4.2.2.2. Just something I learned from one our network engineers, who learned it from someone else...

[+] chrissnell|12 years ago|reply
I started using 4.2.2.1 in early 1999. A friend of mine was a sysadmin at Genuity (then the new owners of that block) and they used it a lot internally. I went on to show it to a lot of my fellow sysadmins and I guess a lot of other folks did the same.
[+] dsr_|12 years ago|reply
Not that anyone cares who wasn't there... BBN was purchased by GTE in 1997. GTE merged with Bell Atlantic to become Verizon. Genuity was spun off, and after it foundered ("Black Rocket") it was purchased by Level 3.

Prior to that, parts of BBN were sold off, and still exist as a subdivision of Raytheon.

Source: I was there for too much of it.

What we told people outside the company about 4.2.2.x: it's there, you can use it for testing or bringing up new systems, please don't use it long-term or heavily. It works by Anycast: let me tell you about that...

[+] NDizzle|12 years ago|reply
That's about when I started using them. I still use it today. It got passed around on IRC somehow. Maybe undernet.
[+] lysium|12 years ago|reply
I did not understand why we shouldn't use 4.2.2.2. If they did not wan people to use it, why is it open? Too bad none of the reports the authors has read about that were linked.
[+] dibarra|12 years ago|reply
The idea is that they can cut off access to non-Level3 customers any day if they wanted to, and they'd be within their rights to do so.

The proper choice would be to use Google DNS or OpenDNS which are provided as a service to the public.

[+] ck2|12 years ago|reply
Just imagine how much traffic they get.

If they really didn't want people to use it, I am sure it would be easy for them to block whole swaths of the net from using it.

[+] orofino|12 years ago|reply
They mean not to use it as your primary DNS server. Pinging it and using it for temporary DNS is likely fine, I wouldn't suggest statically assigning it for permanent use though.
[+] Nux|12 years ago|reply
Been using 4.2.2.2 (and 4.2.2.3) for almost a decade now.

In recent years I stopped using them though because of privacy and reliablility causes; I usually setup a caching server on the local host or network.

[+] eonil|12 years ago|reply
Google should be tracking all the queries on their DNS server.
[+] liveoneggs|12 years ago|reply
I've been blocked by 4.2.2.2 before for (I assume) over-use. It took a year or two but they eventually noticed my traffic..
[+] obilgic|12 years ago|reply
I am curious if google is using the data from its dns service to improve the search index.
[+] efm|12 years ago|reply
I use 8.8.8.8 which is Google's public DNS