DNS problems

[katvis]

Is anyone else having trouble with resolving URL's?

Basically I have 3min or less after connecting to get onto a website before I start getting DNS errors. After this the only way to resolve a URL is by disconnecting and reconnecting then clicking the link again.

I experienced this same problem in many different areas and banging my datacard against the wall doesn't seem to help.

Ps. I'm using vodacoms automaticlly asigned DNS

Someone please help

 

[vodacom3g]

Hi,

When you connect (and you have the DNS problem), won't you check your IP settings with "ipconfig /all" and PM me the output.

 

[vodacom3g]

katvis, everything looks OK in your setup, you're pointing to the SAIX DNS servers.

Do you still have the problem? If so, what happens when you do a nslookup?

 

[katvis]

I've been having this problem (excluding numerous others) since I got my 3G card in march. So yes I am still having this problem.
For instance: Just now I connected, read my mail on gmail (3min) and then nothing..not able to resolve google.co.za or any other site. Then I had to disconnect and reconnect again in order to connect to Myadsl.co.za.

Will try the nslookup thingy and report back

Thanks
Katvis

 

[vodacom3g]

I've been having this problem (excluding numerous others) since I got my 3G card in march. So yes I am still having this problem.
For instance: Just now I connected, read my mail on gmail (3min) and then nothing..not able to resolve google.co.za or any other site. Then I had to disconnect and reconnect again in order to connect to Myadsl.co.za.

Earlier in the year we had a fair number of DNS problems and (by the silence of the forum on the topic) have resolved them by adding new DNS servers as well as other caching engines.

I wonder if you're not seeing a stop in all traffic rather than a DNS problem. This will often come across as a DNS issue as the first thing you're system does is the DNS lookup.

Find an IP you can ping when everything's up and write this number down. Next time you can't work, try and ping this IP. If it fails you've got a connection issue, especially if you can work after a disconnect / connect.

Have you upgraded your firmware and dash to the latest versions?

 

[katvis]

Hi v3g,

I'm using dash v5.1 and firmware v14.

Usually when I'm having this problem nslookup and ping results are fine.

I've send you some results

Any ideas?
Katvis

 

[vodacom3g]

katvis, looks like you are suffering from what became known as the 'first packet loss' problem.

Basically what happens is your 3G connection goes into 'sleep' mode when no packets are sent or received for a while. Then when you start doing something, the first packet sent will wake the connection up and start the transmission process.

This wakeup process can take up to 6 seconds and as the first transaction normally is a DNS lookup, you can see the first DNS will time out. Then by the time the second DNS request is issued, the connection is awake and the response is received.

This is exactly what you are seeing, the first nslookup fail but the subsequent ones work.

One way to test this (when you get the DNS lookup problems) is to open a DOS box and run a continuous ping in the background. This will force the connection to stay open and any DNS lookup should work first time.

We've tuned the network to minimise this problem but there might still be a problem somewhere.

Let me know the outcome.

Anyone else seeing this? The lack of a barrage of DNS failure reports on the forum led me to believe we had this one licked....