DNS Services - File Download Speeds

Has anyone done any tests on the file download speeds for various DNS Services? Please share your experiences. Thanks in Advance.

This morning I downloaded a couple of files comparing ClearCloud DNS with "Obtaining DNS Service Address Automatically"

1st File Downloaded: Norton Internet Security 2011 Trial from the Norton link provided by Softpedia:

Default DNS: ~1.0 Mbytes/sec
ClearCloud DNS: ~0.87 Mbytes/sec

2nd File Downloaded: Windows XP SP3 Network Install exe from Microsoft:

Default DNS: ~1.0 to ~1.1 Mbytes/sec
ClearCloud DNS: ~0.80 Mbytes/sec

My "stated" ISP Bandwidth is 8 Mbits/sec (1.0 MBytes/sec)

 

Personally, I can't see how dns service can affect downloading of single files.
I mean it is technically strange. Dns service dosent work like this.
Dns service just looks up IP adress for sites you put. So once you star dowloading one single file, it looks up IP for it in metter of milliseconds and stops working.
So what I mean is that when you start downloading single file, dns service dosnt do anything and can't affect your speed.
In my opinion what are you seeing is just an illusional, it's just you who belives that it is slowing download. Whereas it was just a coincedence.

 

ClearCloud also has some sort of malware content blocking as well, correct? Perhaps the scan of the site is the cause of the slowdown? I don't know enough about ClearCloud to say, really. It also could just be the website itself, no website is consistent in speed/responsiveness, internet rules apply (network congestion, that sort of thing). The speed differences stated aren't enough to be concerned over anyway, I'm positive the only way you'll know the difference between 1 Mbyte/sec and 0.87 or even 0.80 is by sitting there and staring at the download bar.

 

There should be no difference at least not a significant one. DNS only looks up the IP for the website you wanna go to and gets back to your computer with the response, as mentioned before, all this is done in miliseconds. The only difference might be the time it takes for different DNS services to resolve requests. But that's all. Since DNS services do not scan dowloaded files I don't see how could this affect the speed. It's just a huge blacklist of harmful websites, that's all.

 

Shouldn't be any difference in the download speed.
The dns only translate per example google.com in an IP so your browser can start download and render the website.

If you want to find the best DNS for your connection try with namebench

http://code.google.com/p/namebench/

 

It is all about DNS server location. Changing DNS itself cannot reduce your bandwidth as it has nothing to do with it. However if you are downloading from a server that uses your DNS settings to trace the closest content server to you, you may be given a slower content server. Thats assuming ClearCloud have no servers near you.

 

How would a download server know your dns server?

 

It's actually the other way around. your DNS server will lookup for the download server. depending on how far the dns server is located from the dwl'd server, the speed on the request may vary. also depending on the distance between you and the dwl'd server, the speed may vary aswell...

 

Maybe with this? Don't know for sure though.

 

Shouldn't they use IP GeoLocation?

 

No. Much less reliable.

 

I'm not geeky enough to understand all that is going on in the downloads mentioned in the OP but I know that my download speeds vary depending on where the download is coming from.

When I am doing a slow download, I generally assume that the server I'm receiving from is limiting my speed or its very busy, or its just a slow server.

When we do a download, we don't know what the folks at the other end are using as a server. I know that not that long ago, guys would set up their old 286 PCs as servers and they would bog down very quickly. I assume, that the slower servers today will still bog down when overloaded, however, I rarely run into a download today thats so slow I figure the server is overloaded.

 

I've been using ClearCloud for a few months and download speeds have not changed at all, nor can I detect any browsing speed differences from before.

It's easy to turn to DNS service on and off in Networking so it is a simple thing for any to try out.

 

Good for you, you obviously live close to a ClearCloud server.

Uhm no... You can't just "turn off DNS". I think you mean It's easy to change what DNS service you want to use.

 

yeap, there's no way you can stop using DNS. either you use your IPS's default DNS or you switch to a 3rd party one. In XP, is very easy indeed.

 

Your dns server has nothing to do with the speed of a download. A download host that has multiple servers for content delivery may check your location and redirect your request to a particular server based on location or for load balancing issues but your dns has nothing to do with it.

 

who will resolve my -www.whatever.com- request then?

 

One question guys, does changing DNS affect speed when watching videos on websites like youtube?

Thanks

 

Yes if the DNS server you change to is located further away than your current one, it could *possibly* affect it.

 

Ok thanks.
Regards

 

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What espresso said. DNS does not affect your dl speeds.

In the possibility that the DNS server is crappy and/or located far away and in congested network, it might affect the speed of address resolution.

In that case it might take few milliseconds more before some web page loads first time in browser, after that the address is cached in the PC for some time. Local cached address is used for further access involving that site.

For 99,9% of users matter of DNS is not important. Services like ClearCloud and OpenDNS take the concept of DNS and expand it with content filtering.

Most of the time local security software that filters content slows down your dl speed in far greater capacity. If something doesn't load fast check your AV/FW first.

Also, as has been pointed out, Content Distribution Networks like Akamai can and will direct users to various servers in various locations based on stuff like your location and network/server loads. So the initial test by TheKid7 is suspect at best

 

That's what I was saying...

 

Some more of the same..

DNS stands for Domain Name Server. Most ISPs (Internet Service Provider) have their own DNS servers.
The job of a DNS server is to translate a human readable address into the correct IP address. A human readable address is one that we humans can easily remember, such as wilderssecurity.com.

The service that runs that is called DNS is what tells your computer to utilize DNS. This means when you type in wilderssecurity.com in a browser, the DNS service will translate it for you by using the DNS servers you have stated in the network adapter settings. It is responsible for storing DNS entries in a cache.

Suppose you went to google.com every day. The DNS service would look the name to address up for you, but it also caches it. The next time you go to google.com, the DNS service examines the cache, finds it exists and uses the IP address if found in the cache. This is much faster than going online to find the correct IP address.

The DNS service can also cache addresses that are not 'alive'. If you tried to go to nowebsite.com, and it did not exist, that is, no IP address was found for it by DNS, then it would also go into the cache. The next time you went to nowebsite.com, the cache would return no value, and you would be displayed the usual http404 error page saying cannot find page.

The DNS service clears the cache after x number of days or hours. It will hold x number of DNS entries. You can modify these settings in the registry if you so desire.

Some programs will do thier own DNS service. Outpost Firewall is one. You could let it be your DNS service and turn the windows DNS service off. Turning off DNS will not keep you from using your computer online. Even if you don't have any DNS IP addresses setup for your network adapters, it won't effect you from using the web. It only means that you have to actually know the IP Addresses of the places you want to visit because there is no translation from name to IP without DNS.

Your ISP provides you with DNS servers because your connection to them will be the fastest possible. If you live in Chicago and are using the DNS server from your ISP, it will take your network x milliseconds to travel from your house to your ISP located 3 miles away and return the correct name to IP address translation.

If you are using a DNS server that is located in Miami, your computer will have to send the packets hundreds or thousands of miles to Miami to get the name to IP address translation, then it can proceed to the website you wanted to visit. The round trip from Chicago to Miami might be in xx millisecond or even xxx milliseconds. It takes more time to resolve the name to an address for sure. Using DNS services only means that instead of using the one provided by your ISP that is close and fast (presumably) you are using one somewhere else that provides a list of "bad" addresses. The service is nice, but it may be far enough away that you notice slower browsing due to the increased distance.

Once the name to IP address translation has taken place, your computer no longer has a need for the DNS servers. It has given you the IP address and your browser heads directly there. If you start downloading a file, the IP address of the server the file is on is not going to change while you are downloading, thus DNS has no involvement.

Most likely browsing could be slowed down though if your DNS server is far away or just a slow machine. When you go to msn.com, it might take 2 seconds for the DNS server to return the name to IP address translation. Your computer then heads to the IP address for msn.com. Once it gets to msn.com, there may be a lot of elements on the webpage like ads that point to myads.com and dumbads.com. So while msn.com starts to load, all of the external links there also must be translated as well, so the trip from you to the DNS server might happen dozens of times for just one webpage to load.

A larger cache can help in this. Using the hosts file to house some common IP adresses you visit can help too. Using something like Proxomitron can help because it can block the ads, thus there is no need to use DNS to translate those ads if Proxomitron is blocking them.

Sometimes a website will have what is know as a netblock of IP addresses. Lets say that google owns a netblock of 100 IP addresses. It could assign 20 of them to be google.com. When you go to google.com, you may get any one of those 20. It may depend where you live as to which one you get. Maybe the 20 addresses are spread throughout the world, and when the DNS translation takes place, the IP address you get back points you to the closest one. This is one reason why hosts files sometimes work well, sometimes not. If you choose to use one static IP address for google.com in a hosts file, it may not always be the best one, or it may change and not be valid at all.

There have been some pretty good articles on regtweaks for DNS. Where you go and how often you go there determines if DNS cache tweaks will help you or not.

The bottom line is, once you understand what DNS is and how it works, you can begin to understand why some of what you see happens. Ad blocking increased browsing on dialup like nothing else back in the day. Faster computers (both yours and the DNS server) and faster connections that we have today don't always see such speed benefits of ad blocking, but it might depending on your situation.

Sul.