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MartinFSSr's avatar
MartinFSSr
New Contributor
10 years ago

Fed up with slow DNS lookups

OK, I posted about this months ago and got a few replies with suggestions (thanks--checked them all out) but I am still suffering.

Here's the situation:

Home network with Motorola "Internet router". My client is running Win 8.1. I mostly use Chrome and Firefox, but the info below is from Firefox since it reports connection status at the bottom of the screen (Looking up . . ., Waiting for ... etc.)

The bad experience: especially for busy pages that make lots of connections, like Yahoo and other commercial Web sites, I have very very slow completed page presentation.  Based on Firefox status messages the majority of time is spent waiting for the various contributors to the page (including adwords and other advertising junk.)  OK, but a significant amount of time Firefox is displaying "Looking up xxx"  Maybe 30-40 percent of the total wait time, though this varies and sometimes is not a factor.

The "Looking up xxx" status messages sometimes appear for up to 5-6 seconds at a time (for each lookup.)  This is far above the maximum times reported by DNSBench (see below.) 

In addition, I fairly frequently get an error saying "Can't locate server" and advising me to check my spelling and try again. This is a DNS error, not a failure of the target server to respond. And it's for absolutely mainstream URLs like amazon.com or google.com that are most certainly in DNS and should usually be cached. And these are not URL's I am entering by hand, of course, so they are not spelled incorrectly. 

Nor is this limited to Firefox: in fact, I have gotten "Can't locate server" from my T-Bird e-mail client trying to locate smtp.cox.net!!

Tech support:

I have had a couple of sessions with Cox support, who confirm that my IPv4 DNS settings are correct. My Windows Connection Properties for IPv4 are set to accept the Cox-set defaults: 68.105.28.11,  29.11, and 28.12, in that order. 

Things I've tried:

1. Using Google DNS responders.  -- No apparent difference in performance.

2. Based on a suggestion here in the Cox Forum, I tried changing with my IPv6 settings (disabling IPv6 in Windows, accepting defaults, specifying Google IPv6 addresses.) Again, no apparent difference in performance with any of these.

3. Diagnosis with Gibson's DNSBench. This indicates that performance of the Cox default IPv4 responders is fine--as fast or faster than others in the DNSBench standard lineup, and good absolutely in terms of average and max lookup times. Of course these tests are at a point in time but I've run them several times with similar results.

I am at the end of my rope on this problem. Frankly, all I can think to do is try FIOS . . .

Any ideas out there???

Thanks

9 Replies

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  • @MartinFSSr

    Taking into account your previous forums threads describing this and the fact that you've said that changing DNS server addresses doesn't help  leads me to think this isn't so much a DNS problems as it is a larger connectivity issue to any DNS server.  Being that you have a gateway it actually handles all of your DNS requests so there may be something going on there.  Internet security software would also be trying to filter your web requests and causing delays as well.  It might be interesting to try a different device and see if you encounter the same issues.

  • Chris--thanks.

    I do run Symantec's Norton 360. Is there any specific data to indicate an issue with lookups caused by that product?

    My "cable modem"/router/gateway is a Motorola "SURFboard" model SBG6580.  Any known issues with this device? Any config parameters that should be checked that might be related to this issue?

    I can check my wife's Windows machine to see if it behaves differently but it's running the same OS I am so it seems unlikely to behave differently.  (She is not running Norton so maybe that would be worth a check anyhow.) The only other ethernet-connected devices are Apple TV and a Panasonic Bluetooth player so I wouldn't know how to check them.  Other devices are IOS and are using the wireless interface of the Motorola so again I am not sure how to see if they are experiencing DNS lookup issues.

    Thanks,

    Martin

  • @MartinFSSr

    There's isn't any pattern of know problems however those are components that could definitely cause problems like you're experiencing.  There would certainly be benefit to testing other PC's in your home to see if they are also experiencing problems.

  • Update-- still bad.Still got lengthy (up to 10 seconds) "Looking up [someURL]" messages and frequent "Site not found" for sites like Amazon and Google, which means a lookup timeout or something.

    I checked the suggestion that my Norton 360 AV might be the culprit. Pretty sure not. Turned it off completely to check. Also checked their forums and no reports of this issue.

    I did flush my Win3.1 DNS cache (ipconfig /flushdns, and that did actually seem to provide some temporary relief.

    However, looking at that cache (ipconfig /displaydns) I was really surprised at what was there and what was not there.

    For example, I don't find pop.cox.net (even after accessing it in my e-mail client!)

    And I do find this, which seems odd since AFAIK I don't have any McAfee products installed: 

    mssplus.mcafee.com
        ----------------------------------------
        Record Name . . . . . : mssplus.mcafee.com
        Record Type . . . . . : 1
        Time To Live  . . . . : 0
        Data Length . . . . . : 4
        Section . . . . . . . : Answer
        A (Host) Record . . . : 0.0.0.1


        mssplus.mcafee.com
        ----------------------------------------
        No records of type AAAA


        1.0.0.0.in-addr.arpa
        ----------------------------------------
        Record Name . . . . . : 1.0.0.0.in-addr.arpa.
        Record Type . . . . . : 12
        Time To Live  . . . . : 0
        Data Length . . . . . : 8
        Section . . . . . . . : Answer
        PTR Record  . . . . . : mssplus.mcafee.com

    So, back to asking this Forum for some help  . . . .

    Thanks

  • What happens if you bypass all router/switch/etc and plug your computer direct to the cable modem (not over WIFI, Cat5/6/7 connection only)?  Does it improve?  Do you have any DNS forwarders configured in your router?   How old is your modem?  I found that having Cox internet for 15 years now, when my modem is starting to go back (about every 12-24 months) I get odd behavior including dropped packets, slow loading, never DNS slowness though... but if your modem is a few years old, i would also say it might be worth a replacement. 

  • Mike-- Thanks for the  ideas!

    Not sure how much more I want to invest in this effort before considering trying another ISP. I am realizing there are several layers to how DNS is managed by browser, desktop OS, gateway, ISP etc. and I don't want to become an expert just to kill this bug.

    My Motorola SBG6580 looks like it was made in 2011 or later (at least that;s the copyright date on the instructions.)  I do actually reboot it maybe once a week when it hangs or just to clear out the cobwebs. I suppose I could try a new one, but can't figure why it would specifically mess up DNS. Hmm, unless it's a poor early implementation of IPv6 capability . .

    Again, thanks for the ideas!

    Martin

  • Hi MartinFSSr,

    In February you mentioned checking your wife's PC to see if she is experiencing the same issues. What was the result? I tend to agree with Tecknowhelp, and I'd really like to see if you experience the same issues using a different modem. Cox rental modems are $6.99 per month, pro-rated by the day. If you picked up a modem from a Cox Solutions Store, I bet you would only need it for a day or two of troubleshooting. From the symptoms you've described, it sounds like you'll be able to tell a difference right away! If a new modem solves the problem, you can then decide if you want to purchase a Cox modem, purchase a modem from another retailer, or keep the rental modem. We'd hate to lose you to another provider, especially before exhausting all possible solutions!