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    • CommentAuthorkmorris1
    • CommentTimeJul 16th 2012

    I have been having problems with my home internet and so decided to try OpenDNS. I did a speed test before changing to open DNS and again after and my download speed has DROPPED from 6.63 Mb/s to just 2.69 Mb/s.

    Any ideas why this would be? Or shall I just revert to the ISP defaults?

    • CommentAuthorRed Prince
    • CommentTimeJul 16th 2012
    Coincidence. DNS has nothing to do with download speeds.
    • CommentAuthorkmorris1
    • CommentTimeJul 16th 2012
    Apologies, let me re-phrase. My bandwidth for downloading has dropped. Using
  1.  permalink
    Again, this has nothing to do with DNS. Bandwidth/speed is a function of what you bought from your ISP.

    The only case which might apply is if there is some site from which you download to which you are routed poorly when using OpenDNS servers. This can happen if the site is geographically distributed but gives and OpenDNS location sub-optimal IP addresses, or if your ISP routs you to a distant OpenDNS server to begin with. Even so, such things shouldn't affect performance, but sometimes do. Still, it would not account for overall difference in download speed across all internet usage. (Unless maybe you are in central Asia or Africa.)
    • CommentAuthorkmorris1
    • CommentTimeJul 16th 2012
    I know the MAXIMUM bandwidth is a function of what I bought from the ISP, but not the actual received bandwidth.

    The hype about OpenDNS states that it gives faster browsing. And you guys are both telling me that it doesn't. Yet my speeds are affected significantly. Below are speed tests all taken today:

    6.63 Mb/s 0.84 Mb/s 41 ms - 08:15, on ISP DNS servers.
    2.69 Mb/s 0.43 Mb/s 35 ms - 09:04, immediately post OpenDNS change
    0.37 Mb/s 0.40 Mb/s 45 ms - 12:25, on OpenDNS
    6.63 Mb/s 0.43 Mb/s 41 ms - 12:28, back to ISP DNS

    I tried similar tests with alternative sites, to try and see if it was an anomaly down to as implied it could be above, but obtained similar results.

    Sorry if I'm seeming ignorant, but the results surely can't be just coincidence. By the way, I'm in the UK.

    Thanks again, Kym
  2.  permalink
    "I know the MAXIMUM bandwidth is a function of what I bought from the ISP, but not the actual received bandwidth."

    This is true, as actual speeds depend on all sorts of things including network traffic and how fast the server at the other end is sending data. But DNS is just the phonebook of the internet. It doesn't have anything to do with any traffic aside from the DNS lookup (e.g., "where is" "it lives at the address").

    Generally, yes, OpenDNS can return faster lookups more reliably than other services. Which means that your system commences communication with the site server you wish to reach that much sooner. This is where the "faster internet" comes from.

    Note that if you had not flushed browser and local resolver caches after changing your DNS addresses, you could not reliably say you were ever using OpenDNS at all - you had already visited the site and run the speed test, and would have cached information that is used regardless as to what you have configured for DNS addresses.

    Let's try this. It doesn't matter which DNS addresses you have configured, we'll force that in the command. From a command prompt/terminal window, run the command

    (Windows and sometimes OS X)
    nslookup -type=txt

    (OS X, Linux, BSD, other Unixes)
    dig -t txt @

    and post the output here. If the answer is not "x.lon" (where x is a number), then this could be a problem.
    • CommentAuthorkmorris1
    • CommentTimeJul 16th 2012
    The answer is... "1.lon"

    I did flush my DNS cache, but not my internet history. Bit loath to do that, but I'll try using IE instead of Chrome. And thank you :)
  3.  permalink
    No, not your internet history, just the cache. "Temporary Internet Files" in Win/IE parlance.

    As you are hitting the London servers, I can't imagine what the issue is, if it is not coincidental.

    The best I can suggest is to tracert/traceroute a site from which you download. This will require that you flush the local resolver cache (not browser, in this case) prior to each test, and configuring the DNS IP addresses of your ISP and OpenDNS in turn.

    i.e., with the current DNS IP addresses, flush the cache, the run the command
    (or traceroute, if this isn't Windows)
    change IPs, flush the cache, then tracert the same site domain again.

    You will have to copy and paste the command and output for both here for any hope of analysis. Feel free to edit your username out of the prompt for the command if it displays there and you don't like people seeing it.

    Alternatively, open a support ticket, include the same information, and include a link to your thread here. Or continue in this thread and open a support ticket as well.
    • CommentAuthorRed Prince
    • CommentTimeJul 17th 2012
    “Apologies, let me re-phrase. My bandwidth for downloading has dropped.”

    No need to re-phrase. That is exactly what I was referring to: DNS has nothing to do with your downloading bandwidth. Your downloads happen after your DNS look-up (which only takes a few milliseconds). In other words, by the time you start downloading, DNS is entirely out of the equation.

    “The hype about OpenDNS states that it gives faster browsing.”

    Where do see this hype? OpenDNS, or any other DNS, cannot give you faster browsing. But it can, and usually does, give you faster (and more reliable) DNS look-ups.

This discussion has been inactive for longer than 30 days, and is thus closed.