Modem connects but I cannot load webpages

[#1]

Hi All,
Hopefully someone can help with this frustrating issue.  For two weeks now I have been having problems with my internet connection.  I seem to be going round in circles with Plusnet support who keep implying that it is a problem at my end.
Basically, my modem connects successfully with Plusnet and I can see from network connections that I have started a session at 2Mbit (Plus net have downgraded my speed to improve "stability").  When I start the browser I ger "server not found" and I cannot ping any addresses.  I have swapped out my modem and all cables for new ones.  I have uninstalled all firewalls and anti-virus.  I have tried different browsers and checked all connection settings.  I have even tried connecting two different laptops (one PC and one Mac) directly via ethernet and via wireless to my DSL modem and to a dial up modem.  Still no joy, and I am going nuts...! 
The most curious thing is that on occasion, everything suddenly starts working again.  I had a full day of browsing last week before mid-session I went to a new website and got the dreaded "server not found" message.  The connection has now been down for two days.
I already have an open ticket, but support seem as stumped as I am.  Because they can see that I am connected and they can ping my modem  the implication is that I have got something at my end preventing data transfer downstream.  But with all the hardware swap outs how can this be? 
Anyone else got suggestions?  Thanks a lot.
Ed

[#2]

Have you tried resetting the router to factory defaults? When it connects does it show the correct DNS references?  Are the connection type, etc correct?  Is its IP address and subnet mask correct; are your computers receiving appropriate IP addresses from the DHCP server?
I imagine this sort of thing has been tried but it has to be asked …

[#3]

Could be DNS related?
I had a similar problem at first. I had it set to automatically find a DNS sever address, but it wasn't getting past the router. I had to manually set a DNS address.
Assuming you are using Win XP, go to Control Panel, Network Connections, right click Local Area Network and click Properties. On the general tab, click Internet protocol (TCP/IP), and click Properties. Click "Use the following DNS server addresses" and type 212.159.13.49 and 212.159.13.50 in the boxes below.

[#4]

Hi , had exactly the same problem 2 weeks ago after upgrading my computer. BTW my modem router was supplied by Plusnet, and is a BT1801 hg. At the back of this kit is a small red reset button which you have to push in with a pin and hold for 5 secs which is quite simple really but took me about a week to figure out as there is no mention of this in the downloaded instruction manual. Hope this solves the problem as I had tried everything else which didn't work, but this did.

[#5]

Hi spraxyt, Denzil,
Thanks for you replies.  I agree that a typo/mistake in my router settings or a DNS issue seems the most likely given that my router/modem connects.  However, I have been through all the route settings with Plusnet support several times and all looks correct.  Denzil: I have tied pointing to DNS servers at 212.159.6.9/10 and the ones you suggest and I still cannot resolve addresses and load web pages.
So frustrating!  Thanks anyway.
Plusnet have now reduced my connection speed to 1Mbit to try and get a stable line but it has made no difference.  I am having to walk over to my local internet cafe to deal with all this!!! 
Any other ideas?

[#6]

Quote from: Danglese

Hi , had exactly the same problem 2 weeks ago after upgrading my computer. BTW my modem router was supplied by Plusnet, and is a BT1801 hg. At the back of this kit is a small red reset button which you have to push in with a pin and hold for 5 secs which is quite simple really but took me about a week to figure out as there is no mention of this in the downloaded instruction manual. Hope this solves the problem as I had tried everything else which didn't work, but this did.

Hi Danglese,
Yep, tried the reset button.  I am using a Netgear DG834G combined modem/outer.  I have also tried connecting a simple DSL modem directly to my PC via ethernet to take the router settings out of the equation altogether.
Thanks for your input.

[#7]

EdR,
Have you tried specifying the DNS servers on both your router and computer?
Appreciate you have done so on your Router

[#8]

Quote from: James

EdR, Have you tried specifying the DNS servers on both your router and computer? Appreciate you have done so on your Router

Hi James,
Yes, but I'll give it another go just to be sure.  Thanks.

[#9]

James,
I tried your suggestion and no luck. 
However, after leaving the power off all night pages are now loading this morning.  I've been here before and suspect that the random reliability is set to continue given that no changes have been made vs. yesterday when I could n't access the web at all.  Unless by some miracle things have sorted themselves out on their own, I am seemingly still stuck with a mystery fault which results in me being offline for 3 days and suddenly able to browse for 1 day (...and repeat... ad nauseam :()....

[#10]

Can you always reconnect after you power cycle your router?
Have you checked any idle time-out settings in your router?  You'll need to go to the manual set-up for your connection (Basic Settings IIRC) and check that the idle time-out period is set to zero minutes.