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Something to remember be it Google Public DNS or things like Open DNS: Most CDN's use DNS to map you to one of their servers. E.g.: Assuming your physical loca
by prakash 17y ago
Something to remember be it Google Public DNS or things like Open DNS: Most CDN's use DNS to map you to one of their servers.
E.g.: Assuming your physical location is in Asia/Europe, and let's say you use Open DNS, IP anycast will map you to their London DNS servers (Last I checked that's the only location outside of N. America OPEN DNS has servers). Let's say the website you visit is delivered by a CDN, this CDN's servers in London will deliver content to you even though there might be CDN servers in your ISP.
- mrkurt 17y agoThat's assuming DNS based geolocation, though. Some CDNs (including Cachefly, who we use) are anycast driven, so it doesn't matter where your DNS servers are located.
- javery 17y agoMost of these providers, like Open DNS, have location based caching as well. If you go to OpenDNS' support page you can see the different caches they have and what IP is currently resolving for each region.
- prakash 17y agoCorrect, which is why I picked the Asia/Europe example. Open DNS has servers in various cities in the US, but only one outside of the US.
- amalcon 17y agoYou can always run your own instance of bind (or dnscache if that's more your style) to get a local nameserver that doesn't have any garbage on it. The drawback is that you'll often lose a few ms to refreshing your cache, which will cause popular-but-non-CDN content to be slightly slower.
- prakash 17y agohttp://news.ycombinator.com/item?id=497314 http://news.ycombinator.com/item?id=497314