COMPLAINT: Endless DNS errors

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aisne

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Can Vodacom *please* advise me what I should do next. Situation is:

About every third day that I use my 3 G connection I get so many DNS errors that I'd estimate the actual cost for useable bandwidth is substantially more than the advertised rate per MB, because I'll surf via say Google to a page and then about 1 in 3 pages gives me a DNS error.

Right now there was just NO WAY I could get onto yahoo.com via normal processes. I had to do an nslookup on yahoo.com and then enter the IP address, because of this DNS error again. It happens too often to be acceptable, and it happens with popular sites that are definitely not down.... google.com, yahoo.com, abebooks.com, bbc.co.uk etc....

It doesn't happen all the time, yesterday I spent several hours on the net and it was fine.

I really need answers now....

On the first two occasions that I logged a fault in the last few weeks, I was subsequently fobbed off with a generic type statement something along the lines of 'yes we were experiencing network instability yada yada yada.' I now want to see log files, get specifics of the actual root cause of the problem, and see the problem resolution, who implemented it, how it was tested.

I worked in this type of support environment for a cable company in Europe so I know what this game is about and generic BS that the problem is 'fixed' doesn't hack it. When someone tells me something like this, all it really means is that no one really looked into it, no one could replicate it, no one bothered to dig deeper, and then when the problem didn't reappear, they hoped it wouldn't reappear, and they fobbed the customer off. Well, let me tell you.... The Problem Always Reappears...... (like now).

Real answers would be great. If it's configuration on my machine, cool, let me know what I must do.... But so many DNS errors are just a waste of my time...

Second minor annoyance: Spent 10 minutes on 155 -call was dropped twice and the third time when I pressed 0 as instructed, I got put through to the normal call centre, who then put me back onto 155 where my call got dropped again. Decided that it was less sweat to type the IP address than to try and get results.

Thinking of adding my fave sites to etc/hosts or wherever the host file is in Windoze so that I can at least get on with my life.... How sad is that?

-Aisne
 
There seems to be two contributing causes to this whole DNS issue.

1) I agree there appear to be network related issues and I've escalated it already. Your post will help enforce this.

2) I often see that on second attempt the URL will resolve, as if the Windows DNS lookup timed out just to soon. I've asked the Windows experts if it's possible to increase the Windows OS DNS timeout but so far have come up with a blank.

Can any forumites help?

I.e. how do I increase the DNS timeout period? (On Windoze?)
 
Thanks for this, but not to sure if this is what we're looking for.

I'm looking for a 'network' timeout setting, i.e. how long the system will wait for an answer from the DNS server before timing out. We need to increase this so the DNS client won't quit to soon.

Maybe there's another registry entry for this?
 
Thanks will go through these. I still need to increase the timeout to confirm my idea but there seen to be slightly longer latencies involved, maybe just enough to be marginal.
 
Are you sure your being assigned the right ip address's for the dns? maybe he has them statically set to some other dns server!
 
I was waiting for the "Fix Windows by installing Linux" answer. :)

I would still like to see an increase in Windows DNS timeouts as I believe this is the root cause of a lot of the symptoms.
 
I got these DNS errors on Telkom ADSL a few times already.... bummer.
 
Hi Vodacom3G,

It definitely doesn't always resolve on the 2nd URL attempt or on the 20th or the 200th in my case, so we probably have mutliple issues here being masked by similar symptoms. I don't think that increasing the Windows timeout is a solution - it is merely a workaround. What I need to know is why this problem occurs on the Vodacom network.

FYI I am also on the Sentech network at work (we access directly onto the Constantiaberg cell without going via myWireless). NO DNS ERRORS. At the other company where I consult, we use a Diginet line (painfully slow) but NO DNS ERRORS. Prior to the Sentech connection we used ISDN and there were NO DNS ERRORS. My friend runs ADSL at home and I surfed a lot on her connection and guess what NO DNS ERRORS. My examples could go on and on here. Bottom Line: These DNS errors are not an internet norm.

Fixing/Configuring Windows timeouts (although I like the idea that Windows needs fixing as I'm not a fan) is not the solution. The solution is to identify where and why these errors are ubiquitous on Vodacom's network. And then change the network configuration.

What are the DNS settings meant to be on my machine because at the moment its configures for DHCP with 'use default DNS' or whatever the wording is...?

If is isn't the TCPIP settings on my machine, then I'm willing to give 20-1 odds that it will be a network configuration issue on the Vodacom network......

There are some excellent O'Reilly books on DNS that Vodacom might like to invest in :-)

Cheers,
Aisne
 
Oh and also forgot to remark, increasing the DNS timeout may resolve the problem in one sense, but realistically it means that I would have to wait for ages before the page is retrieved. That defeats the object of high data rates doesn't it? I mean, yes I get broadband speeds, but ONLY after waiting 10 times longer for name resolution that on my diginet line at work...... LOL...

Cheers
Aisne
 
Thanks, OK I'll try this out. Out of interest, do you know the IP address of the DNS servers used by Vodacom?

Aisne
 
Wouldn't the real "fix" be to sort out the DNS servers so that they're not so slow on responding to queries?
 
Fixing it would be 1st prize, but who can wait?

The automatically assigned DNS seems to be an internal (non routable) address 10.11.12.13 and 10.11.12.14.

Check from the command line with ipconfig /all. (Start/Run, enter cmd, click OK, enter ipconfig /all).
 
TCP/IP dynamically increases timeouts as well, as packets gets lost. I use some DNS servers located in Ireland from Windows via VPN and that works fine (via Diginet and 3G), so pure time to the server in not always the problem. Has vodacom maybe looked at where are their DNS servers located in the network? Maybe the paths to them are very long or unreliable or something like that. Or the servers themselves can maybe not handle the load. But I am not a network expert, so I am just guessing.
 
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There is still a big problem with DNS in SA - lots has been posted about it already on this forum. Unfortunately, it is not limited only to Vodacom - ADSL and IS customers also experience similar problems. In my experience, and in my opionion, the problem is mostly caused by a. inadequate hardware at SAIX, and b. Bandwidth shaping devices that limit the amount of traffic DNS can consume! I have managed to easily replicate the DNS resolve issues at work by throttling DNS on a QOS device.
My suggestion - manually configure DNS entries, and assign an "off" network DNS server as your secondary. This seems to help. Alternatively, install a DNS server locally, list the proper root hints, and assign SAIX and a.n.other as your forwarders.
Hope this helps!
 
This is what I've suggested, bring a DNS server to the APN. This should resolve any potential server-related as well as non-3G network problems.

I still maintain that, due to the longer latencies on (especially) GPRS and sometimes 3G, you can experience DNS timeouts on the client.

Having the ability to tweak the client-side timers would help here, not at transport (TCP or UDP) level, but at application (DNS) level.
 
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