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Solution

A Bit Of Info About 'dns'?

frankwakeman
4: Newbie
I've tried to do a bit of reading up on this but I've found changing from the standard Vodafone DNS settings has slightly improved the service at times when I can't connect at all.

I've used those DNS settings beginning with 10... and the 'open DNS' settings I found in a thread here, ending .220, and settings that were standard with the Linux drivers on your Betavine site, one of which is 212.73.32.67. The open DNS worked better than the 10... etc setting but kept prompting me to fill in 'exceptions' e.g. when using MySpace. I've even tried having only a primary setting, and I currently have just 212.73.32.67. Does it matter if you have no secondary DNS?

Is the setting I'm using okay to use? And lastly, as Vodafone had acknowledged that their standard DNS settings were a problem about six weeks ago, has anything been updated or resolved?

This is using Ubuntu 9.04 rather than Windows, and no Vodafone software, as I no longer get any connection at all from the VMC software for Vista - immediate disconnections repeatedly at any time of the day. I definitely won't be renewing my contract next February, but with a way to go yet if there's further tweaks and knowledge to be had I'll give it a go.

Thanks in advance for any informed layman or pro replies.
6 REPLIES 6

Neil_Brown
14: Advanced member
14: Advanced member
You do not need a secondary DNS, but, it's useful if the primary DNS is failing.

What do you have in:

/etc/resolv.conf

or

/etc/ppp/resolv.conf
Neil

frankwakeman
4: Newbie
Hello. Thanks,

/etc/resolv/conf contains this:

# Generated by NetworkManager
nameserver 212.73.32.67

The other file you named isn't there, although there is a file

resolv.conf.pppd-backup which just says:

# Generated by NetworkManager

...if this is of any use. While you're there, additionally, is it possible to turn off optimisation in Network Manager e.g. under PPP settings, those three checked boxes which don't seem to alter if you try to change them normally? Or is that something else and does this have no effect on optimised images? This compression has got worse lately for some reason, very splodgy images like a child trying to go careful with felt tips or otherwise jumbled, like the login box on myspace.com or people's avatars on the Linux Mint forum, and this is not resolved by clearing the cache.

Ta.

heady
4: Newbie
...if this is of any use. While you're there, additionally, is it possible to turn off optimisation in Network Manager e.g. under PPP settings, those three checked boxes which don't seem to alter if you try to change them normally? Or is that something else and does this have no effect on optimised images? This compression has got worse lately for some reason, very splodgy images like a child trying to go careful with felt tips or otherwise jumbled, like the login box on myspace.com or people's avatars on the Linux Mint forum, and this is not resolved by clearing the cache.


Vodafone uses network based image compression for most GPRS links - both GSM & 3G. There has been talk on here a while ago that the network based image compression is restricted to particular IP ranges; however, these values were not discussed. There was also a reply from a Vodafone mod who said that Vodafone is looking to remove network based image compression from their 3G plans in future but there was no confirmed timeframe.

As your running linux - Ctr+Refresh in Firefox and derivatives and just normal refresh using Konqueror - (not sure about the rest) will reload images without compression (most) of the time.

I run a caching proxy server between Vodafone and my browser so that I cache non-compressed images locally and therefore, only have to force refresh once per site usually. But this causes other caveats so this may not be a solution to you.

Regarding DNS - at least for the last 2months or so Vodafone has been known for losing DNS packets in the network somewhere.

One thing I've done is also implement a caching DNS server that alleviates some DNS issues - again with many caveats. So it might not be for you.

Having only one DNS server in /etc/resolv.conf is fine for most of the time. Having more than one allows for secondaries if the first fails - they get tried in turn. Alternatively, if you have the rotate option it will change the behaviour to that of round-robin amongst the list of DNS servers.

One thing that I've yet to try in anger is: <> which translates DNS requests from the unreliable datagram protocol (UDP) to a slightly more reliable transmission control protocol (TCP). In theory - by looking at the tcp stats this would show where the Vodafone DNS issues lay - either within the network or at the server. However, I've yet to go down this path.

If you have further issues regarding the Linux side of the equation - then the normal response is to head over to <> as you'll have better Linux support there.

frankwakeman
4: Newbie
Yes, I do use Betavine sometimes.

Although the more technical stuff you describe is beyond me, thanks for the ctrl & refresh tip! - I've been pressing F5 only instead of ctrl & F5, and it does replace the garbled stuff.

Neil_Brown
14: Advanced member
14: Advanced member
Frank - /etc/resolv.conf looks fine.

In terms of image quality - I've never noticed, I'm afraid, since I use an SSH tunnel to my server and then outwards from there, so, images are always normal quality.
Neil

Jenny
Moderator (Retired)
Moderator (Retired)
Hi Frankwakeman,

In all honesty I’m a bit stuck here! :wacko:

I’m going to ask one of my more technical colleagues to take a look at this for you tomorrow.

Don’t worry we’ve not forgotten about you, we’ll be in touch tomorrow! :)
All the best,

Jenny
eForum Team