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In a CDN'd world, OpenDNS is the enemy
- Piskvorrr 14y ago"Fairly simple to set up BIND" - well yes, for someone with access to the local gateway and the ability to install a caching DNS resolver, this is a good option. Unfortunately, most crappy DNS servers are with residential ISPs - and most residential users don't run anything near an usable distro on their gateways. For a user who's just competent enough to change the DNS settings, the "slow CDN access" versus "spotty DNS" tradeoff will be heavily weighted towards the first option.
- piffey 14y agoHow many home users will even notice the few second difference and think there's anything they can do about it though?
- Piskvorrr 14y agoGood point. The ones likely to notice would be the ones capable of setting up a local caching DNS server (that is to say, the HN crowd).
- icebraining 14y agoWhy not just install the DNS resolver on the client machine? Sure, you'd miss out on the shared cache, but I doubt it'd make much of a difference.
- sanxiyn 14y agoThis is what I do. Caching DNS resolver needs no configuration whatsoever. It is literally "apt-get install pdns-recursor" and edit /etc/resolv.conf to point to 127.0.0.1.
- Macha 14y agoAnd on Windows? Or a Ubuntu user who only knows how to use the GUI? Or OS X?
- Dylan16807 14y agoI don't know about windows but it's pretty easy to install a single program and either edit a text file or go into network settings with a gui.
- sanxiyn 14y agoWhat I wrote is actually possible to do on Ubuntu without ever opening a terminal.
- Piskvorrr 14y agoNot to mention that the NetworkManager version shipping with 12.04 does this by default.
- deleted 14y ago[deleted]
- vld 14y agoThis article is from 2010, back when the edns-client-subnet [1] draft wasn't even published. I believe most CDN's are now whitelisted with Google's and OpenDNS's edns list, so you'll much better results. also see edns-client-subnet demo [2] [1] http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-00 http://tools.ietf.org/html/draft-vandergaast-edns-client-sub... [2] http://news.ycombinator.com/item?id=4174512 http://news.ycombinator.com/item?id=4174512
- josephcooney 14y agoI don't know how many do, but Apple digital media purchases don't. OpenDNS causes movie download times to blow out to weeks for me on itunes.
- elithrar 14y agoApple use Akamai, who are the exception here; which explains your problem.
- le 14y agoApple has a long running relationship with Akamai, but they also use Limelight and Level 3 for content delivery as well.
- SoftwareMaven 14y agoReally? I've never had that problem for movies. There are times apps seem to take a long time to update, though. I'll have to experiment.
- sirn 14y agoThis issue will be (is?) solved with the "Client IP information in DNS requests " DNS extension[1]. A year ago, David Ulevitch (OpenDNS's owner) mentions in HN post that he already got it working for all Google properties and few other CDNs (except Akamai).[2] [1]: http://tools.ietf.org/html/draft-vandergaast-edns-client-ip-01 http://tools.ietf.org/html/draft-vandergaast-edns-client-ip-... [2]: http://news.ycombinator.com/item?id=2941948 http://news.ycombinator.com/item?id=2941948
- omh 14y agoIs there a technical reason why Akamai don't support this yet? It seems that it would be in their interests to improve this. Both for a better experience for users and lower latencies from their point of view. Or is it just that they're big, and it's a complex change?
- acdha 14y agoMy guess is that they're not receiving strong demand from their major customers - since they have so many massive users and a long-term code-base it makes sense that they'd be rather conservative.
- deleted 14y ago[deleted]
- Igal_Zeifman 14y agoNot only this is from 2010, but I also don't understand the point. It states "he solution would be to use your ISPs DNS server rather than these Global providers." But this is only true if you are a strictly local website (how many of those are there?). From what I saw, if you are receiving traffic from different Geo-locations (as most do) you should stick with Global providers. He should be comparing the same ISP for all cases (not changing each time to another local ISP).
- bashzor 14y agoFunny, I was wondering about this exact thing yesterday. Trying Google though (hadn't thought about other DNS providers), the traceroute went to somewhere within Europe or maybe even Amsterdam. Being from the Netherlands, that'd be very close, there just is no way 13ms is a ping from America. So I guess 8.8.8.8 is multihomed or however they call it. Still, the geoIP databases claim it to be in Mountain View where Google is, so I wasn't not sure exactly how this affected 'split horizon' (on which, as far as I know, the DNS decides which IP(s) to return for the requested hostname).
- gorset 14y agoAccording to the compute engine talks from this year's google IO, they have their own private network covering most of the world and uses anycast for external Internet Addresses. This basically means that a connection from you will be routed to the nearest google data center, and from there to the final server using google's private network. Google DNS uses both anycast and multihoming, so you will both be routed to the nearest google data center and then to the closest DNS server inside google's private network.
- jemfinch 14y agoTo be precise, HonestDNS uses Anycast routing to situate the same IP at multiple places around the globe, letting BGP and least cost path routing send users to their best location. The DNS protocol works particularly well for this.
- gdamjan 14y agoCDNs could solve this by using BGP anycast routing.
- astrodust 14y agoDoes this work with TCP? The only implementations I've seen are for UDP which is stateless and unaffected by route flap.
- amalcon 14y agoIn theory yes, but BGP anycast routing is really bad in performance terms. BGP doesn't care about performance, only politics and cost, so you can get all sorts of weirdness.
- jemfinch 14y agoCDNs are typically used for transferring large objects, for whom the anycast routing instability is a real concern. If a client's anycast endpoint changes in the middle of a connect, the client will receive an immediate RST from the new server.
- le 14y agoMajor CDNs do use anycast routing, in conjunction with DNS/geolocation based routing in locations where anycast's results would be unpredictable (usually in locations where there are many POPs.)
- mcbridematt 14y agoThis has long been an issue; particularly for Australian users where using a foreign DNS server will cause CDN requests to travel across the Pacific Ocean. This is one example (from 2010): http://apcmag.com/why-using-google-dns-opendns-is-a-bad-idea.htm http://apcmag.com/why-using-google-dns-opendns-is-a-bad-idea... From my location Google DNS terminates within the country - so no issue there. Not sure about OpenDNS, however.
- gte910h 14y agoI find putting the primary DNS on my router to by my ISPs, and the second to be a 8.8.4.4, etc, type one to be a nice compromise.
- amalcon 14y agoThis is actually a pretty good idea if you've noticed some sort of systemic problem with your ISP's DNS. If the secondary is likely to be down at the same times as the primary, it's a good way to avoid that dependency.
- mrcharles 14y agoThis article misses one of the main reasons for people to use OpenDNS/Google DNS, which is to prevent ISP hijacking of domain names or redirection of unresolved domains. I personally use it because I am extremely uncomfortable with my ISP catching mistyped URLs and redirecting me to a page filled with ads, searches, and other bogus things.
- sandstrom 14y agoThis is also the revenue model of OpenDNS (although I agree that they are less aggressive than some ISPs).
- mrcharles 14y agoAh, my bad. I actually use Google DNS because they don't hijack anything, which was my prime reason. I'd assumed Open DNS was similar. That being said, I can still get behind at least choosing to let someone hijack those pages, rather than sticking with a company that does it automatically.
- sp332 14y agoAt least you have the option of throwing a few bucks at OpenDNS and they'll stop filtering, or even add custom redirects/shortcuts for you.
- gioele 14y agoSo you have to pay to get what installing unbound (Win, OSX, Linux) on your machine will give you for free?
- sp332 14y agoNot sure what you mean by unbound, but your Windows box does not have a DNS server installed by default. Most people depend on the DNS server that their ISP runs. If the ISP is doing unwanted redirects or filtering, or is just unreliable, you can point your DNS to OpenDNS which is fast and reliable. You can either use it for free and it will show you ads when you typo, or you can pay them some money for their service. (edit: expanded)
- djbender 14y agoThe main reason I use an alternative DNS is because my ISP's DNS service goes down constantly.
- nl 14y agoIt's worth noting that ISP-run DNS services aren't entirely free of these issues either. In Australia, both Vodaphone and (to a lesser extent) Optus resolve all DNS queries from a server farm in a single location. It is unfortunate, because mobile clients are the perfect use-case for highly localized CDNs.
- darkhorn 14y agoThe biggest Turkish ISP blockes all porn sites. Thus the users need to use GoogleDNS.
- igrigorik 14y agoInstead of relying on a few pings, run the test for yourself: http://code.google.com/p/namebench/ http://code.google.com/p/namebench/ The Google DNS team built the tool above, and it allows you to test your current setup against a number of DNS vendors + allows you to share the data, etc.
- lftl 14y agoIf I understand correctly, these are addressing two different issues. Namebench seems to be interested in finding out which DNS server will return a look up request the fastest. The OP though is saying that because global DNS providers don't currently pass along information about my local IP address, I'll get a suboptimal response that points to an IP address that may not be the fastest for me. Or does namebench actually test the IP addresses you get in response to test their response time?
- gte910h 14y agoYou should actually be using a free, fast DNS near you, with at least one not on your ISP. Here is a program to help find them: http://www.grc.com/dns/benchmark.htm http://www.grc.com/dns/benchmark.htm
- michaelcampbell 14y agoNetwork neophyte here. Am I wrong in that CDN's ultimate goal is geolocation of the requestor, and they're using DNS to do that? And if the user uses a DNS that isn't "near" him, this scheme fails? If that's correct, is there no better way to do user geolocation than the nameserver they choose to use? That seems weird to me.