The Downside Of Using Google/open Dns Outside The Us

[Dork]

While researching another DNS issue, I stumbled across several references to an apparent disadvantage in using open DNS servers instead of your local ISP's, especially when you are located outside the US or other major internet hubs.

Maybe it's already well known but I had never heard of this issue before. It goes something like this;

The big CDN networks like Akamai that distribute data around the world rely on DNS to determine your geographical location and therefore which servers you should be directed to in order to get the lowest latency and highest download speeds (for example Youtube's local caching and/or co-location servers).

If you google it, there are many references to this problem. Here is an example http://apcmag.com/wh...-a-bad-idea.htm

Both Google and Open DNS acknowledge the issue and are addressing it by spreading their DNS servers around the world. However according to Google's list, there isn't one in Thailand.

I routinely enter 8.8.8.8 or 8.8.4.4 into my router's DNS or as a DNS forwarder but maybe I should reconsider.

Has anyone experimented with this?

[BlackPuddingBertha]

I always use a non-Thai DNS server as my second DNS server, regardless of what the consequences are. The local ones are just too crappy to do otherwise.

[JakeBKK]

If you use Open DNS in Thailand you are using the DNS servers in Singapore. If you use mobile internet your DNS will be overridden anyway. Akamai here with open DNS settings will put you on a Japanese server ( likely ) which is okay. When you ping opendns , i am aroud 50ms , Akamai SG server is around 137 ms. Just for the fun of it - i pinged 3BB's DNS (my isp) with an average of 110 ms.

As an additional plus - you do not have to mess around with a certain dns filter list.

Edited January 12, 2013 by JakeBKK

[lomatopo]

There have been quite a few really good threads here on this subject. My vaguest recollections:

Namebench is a decent utlity.

Google (8.8.8.8/8.8.4.4) has DNS servers in Singapore, and usually perform best, and tend to be reliable.

OpenDNS usually performs badly.

One's own ISP DNS servers give good response times but are often off-line, subject to being unreliable.

[Dork]

There have been quite a few really good threads here on this subject. My vaguest recollections:

Namebench is a decent utlity.

Google (8.8.8.8/8.8.4.4) has DNS servers in Singapore, and usually perform best, and tend to be reliable.

OpenDNS usually performs badly.

One's own ISP DNS servers give good response times but are often off-line, subject to being unreliable.

This is not about DNS server performance. What is being suggested is that by using DNS servers in a different geographic location, an unintentional side effect is that your download speed can suffer dramatically or, for example, youtube streaming is slowed down.

That's because content delivery networks like Akamai use the location of your DNS server to determine which content server offers the best performance for your location and should deliver you the data. So in theory, if the DNS server you specify is located in the USA, then your data will come from the USA rather than a server located much closer.

[Chicog]

There have been quite a few really good threads here on this subject. My vaguest recollections:

Namebench is a decent utlity.

Google (8.8.8.8/8.8.4.4) has DNS servers in Singapore, and usually perform best, and tend to be reliable.

OpenDNS usually performs badly.

One's own ISP DNS servers give good response times but are often off-line, subject to being unreliable.

This is not about DNS server performance. What is being suggested is that by using DNS servers in a different geographic location, an unintentional side effect is that your download speed can suffer dramatically or, for example, youtube streaming is slowed down.

That's because content delivery networks like Akamai use the location of your DNS server to determine which content server offers the best performance for your location and should deliver you the data. So in theory, if the DNS server you specify is located in the USA, then your data will come from the USA rather than a server located much closer.

How many decent content servers are there in Thailand?

[lomatopo]

This is not about DNS server performance. What is being suggested is that by using DNS servers in a different geographic location, an unintentional side effect is that your download speed can suffer dramatically or, for example, youtube streaming is slowed down.

That's because content delivery networks like Akamai use the location of your DNS server to determine which content server offers the best performance for your location and should deliver you the data. So in theory, if the DNS server you specify is located in the USA, then your data will come from the USA rather than a server located much closer.

Like I said, there have been quite a few great, and informative threads on this very topic here, with lots of insight from some knowledgeable people (not me).

Namebench can be used to identify viable DNS servers based on your location. These are ranked and then you can choose/experiment with these.

It seemed like, in those various threads, that most here preferred/recommended Google's DNS servers in Singapore, or their own ISPs' DNS server, or some combination of the two.

[Dork]

There have been quite a few really good threads here on this subject. My vaguest recollections:

Namebench is a decent utlity.

Google (8.8.8.8/8.8.4.4) has DNS servers in Singapore, and usually perform best, and tend to be reliable.

OpenDNS usually performs badly.

One's own ISP DNS servers give good response times but are often off-line, subject to being unreliable.

This is not about DNS server performance. What is being suggested is that by using DNS servers in a different geographic location, an unintentional side effect is that your download speed can suffer dramatically or, for example, youtube streaming is slowed down.

That's because content delivery networks like Akamai use the location of your DNS server to determine which content server offers the best performance for your location and should deliver you the data. So in theory, if the DNS server you specify is located in the USA, then your data will come from the USA rather than a server located much closer.

How many decent content servers are there in Thailand?

I don't know. Possibly not many. But even so there are plenty of them located in HK & Singapore which is obviously preferable to the US or Europe.

[Dork]

This is not about DNS server performance. What is being suggested is that by using DNS servers in a different geographic location, an unintentional side effect is that your download speed can suffer dramatically or, for example, youtube streaming is slowed down.

That's because content delivery networks like Akamai use the location of your DNS server to determine which content server offers the best performance for your location and should deliver you the data. So in theory, if the DNS server you specify is located in the USA, then your data will come from the USA rather than a server located much closer.

Like I said, there have been quite a few great, and informative threads on this very topic here, with lots of insight from some knowledgeable people (not me).

Namebench can be used to identify viable DNS servers based on your location. These are ranked and then you can choose/experiment with these.

It seemed like, in those various threads, that most here preferred/recommended Google's DNS servers in Singapore, or their own ISPs' DNS server, or some combination of the two.

Did you read what is written? You and the threads you are referring to are talking about DNS server performance. This issue has got nothing to do with that.

[wimpy]

I don't know. Possibly not many. But even so there are plenty of them located in HK & Singapore which is obviously preferable to the US or Europe.

Wouldn't that be dependent on the capacity of the cable and the amount of traffic it is carrying? I would think the cable to the US has more capacity than one going to HK.

[lomatopo]

Did you read what is written? You and the threads you are referring to are talking about DNS server performance. This issue has got nothing to do with that.

I did glance at the article you linked, but saw it was nearly three years old.

I am fairly certain we are talking about the same thing, and yes, it has been covered in many great threads. But maybe I am still not getting your point(s).

What are you recommending, exactly?

Before Google expanded their DNS network globally, including in nearby Singapore, this article, and what I perceive to be your "advice" may have been valid. Based on all the threads we've had here I'm not so sure that is currently the best recommendation? But I think we;d all welcome any advice you care to share.

[Dork]

Did you read what is written? You and the threads you are referring to are talking about DNS server performance. This issue has got nothing to do with that.

I did glance at the article you linked, but saw it was nearly three years old.

I am fairly certain we are talking about the same thing, and yes, it has been covered in many great threads. But maybe I am still not getting your point(s).

What are you recommending, exactly?

Before Google expanded their DNS network globally, including in nearby Singapore, this article, and what I perceive to be your "advice" may have been valid. Based on all the threads we've had here I'm not so sure that is currently the best recommendation? But I think we;d all welcome any advice you care to share.

Yes you are right, that link from 2010 was a bad choice. I just took it as an example but there many more recent reports of the same thing. If you google "Akamai public DNS" you will get lots of links to the issue.

I wasn't trying to give any advice because I've only just heard of this issue but after reading a bit, it does make sense. And it's because there has been quite a few threads here discussing Public DNS but also a lot of threads discussing lousy download speeds from international servers. Perhaps there is a connection.....

As far as I recall, the threads discussing Open/Google DNS are centred on the improvements in latency and reliability when compared to ISP's DNS. The suggestion here is that using public DNS can considerably (by 100's of % in some cases) slow download speeds because it "breaks" Akamai's system of content distribution because it is dependant on knowing your location. It's not about DNS itself because DNS was never designed to be used in this way.

Anyway, it could be a load of nonsense. But I kind of doubt that since both Google and Open DNS acknowledge that there is an issue. Since neither of them are offering free DNS out of the goodness of their hearts, they wouldn't do that unless there was some truth in it.

[lomatopo]

You can mess around with the "Big Table" in this article, selecting different CDNs and see the effects in Thailand. It shows OpenDNS and Google DNS as better than public DNS.

http://www.cdnplanet...-opendns-users/

[Tywais]

I still don't understand what is being said. The GeoIP is determined by your current IP connection and not from the DNS IP. Doesn't make sense otherwise. Now if you are talking proxies, that's certainly different and can cause such issues.

[BlackPuddingBertha]

I still don't understand what is being said. The GeoIP is determined by your current IP connection and not from the DNS IP. Doesn't make sense otherwise. Now if you are talking proxies, that's certainly different and can cause such issues.

This explains it: http://00f.net/2012/02/22/akamai-vs-public-dns-servers/

It's perfectly true that if you use a DNS server that is not local to you then file servers (akamai, youtube etc.) may serve you from some distant location and this may have an impact on the speed. But the alternative is using exclusively local DNS servers and here that means that many sites wont resolve at all.

Thai DNS servers are amazingly crappy and so I use one of each, the local one first. This gives me the best of both worlds.

[Tywais]

I still don't understand what is being said. The GeoIP is determined by your current IP connection and not from the DNS IP. Doesn't make sense otherwise. Now if you are talking proxies, that's certainly different and can cause such issues.

This explains it: http://00f.net/2012/...ic-dns-servers/

Thanks for the link. Makes it a bit clearer in how they are doing it.

[2008bangkok]

Sorry but this is aload of crap, all these 'articles' say there is a problem but nobody says what the problem is, one would assume that if you went to a website that wanted to know your geographical position to determine the closest server for you to download a file then they would probably use your actual IP address. Also w does a web server know what DNS server you are using, this info is not sent out in a IP packet

[BlackPuddingBertha]

Sorry but this is aload of crap, all these 'articles' say there is a problem but nobody says what the problem is, one would assume that if you went to a website that wanted to know your geographical position to determine the closest server for you to download a file then they would probably use your actual IP address. Also w does a web server know what DNS server you are using, this info is not sent out in a IP packet

That link I posted explains it, sort of.