Internet connection ok...but no internet
 

Hello.
Just had a week without internet. A rather curious fault developed last Tuesday - suddenly lost the net on my desktop (wired connection to my BTHomehub 2). Also couldn't get the net on my mobile, or any other wireless device either. Landline working fine, Homehub indicator lights and administrator page showing Broadband connection good, and Internet connection OK. Restarted Homehub. No change. Reset Homehub to default config. No change, Swapped Homehub for my old Netgear wireless modem, still the same problem - Broadband and Internet lights showing OK, but no internet! Swapped Netgear modem for my very old BT Voyager (wired connection only) - lights again showed Bb and Internet OK, but still couldn't connect to the net with any device.

Finally took deep breath and phoned BT callcentre. Won't go into it, but despite eventually agreeing that the fault must be at the exchange, said they'd have to send me a new Homehub before they could get their engineers to check the line.

Got new Homehub today, but before I'd taken it out of the box for the pointless swap, the internet started working again via my original Homehub. I guess BT must have looked into it anyway, and fixed it.

Anyone any idea what could make all my modems/routers think there are working Broadband and internet connections when there aren't?

Coincidence engine?

Depends what what the modem / router shows as "good connection". Usually it is just layers one and two (physical and link/MAC), which may be just fine and dandy, but if layer three (IP layer) is not working then... nada.

Maybe the DHCP address is not being allocated, or is wrong, or the upstream router is faulty (at a layer three level), or DNS servers are down (or incorrect), or gateway is misconfigured, etc.


SD

Thanks Saab, that's the sort of technical stuff I was curious about! I guess I'll never find out for sure (as BT seems to have fixed it now), but that level three layer, IP addressing bit seems to make sense and fits in with my symptoms.

I went on a short course last year covering IP addressing (etc), and it all made perfect sense while the bloke was teaching it. Bewildered when I thought about it ten minutes afterwards though. :O

Blues&twos,


And that was probably only IPv4, try getting your head around IPv6 ! :{

I wrote the following PowerPoint presentation (rather hurriedly) to educate some of my call taking staff in the ways of IP. See whether it makes a little more sense.

(it's only IPv4 though, I doubt IPv6 will take off in it's present form despite the 'readiness' for it)

http://dl.dropbox.com/u/990326/Netwo...20Internet.ppt

BLUES....

Have been staying at the daughter's place in Sth Oxfordshire for a couple of weeks since the Easter break - exactly the same problem....

Lost all Internet connectivity last Wednesday night...Fiddled around with wires, connections, etc, and still nothing....

Went through her Orange manuals, and found that although the Inventel test site said the Livebox was connected to the internet, absolutely nothing coming through....

Thought it was my machine - tried with another old machine of the daughter, still nothing, so just gave up trying and left it for the daughter's boyfriend to solve when he returns home next week...

Then last night, about 22.00 and totally out of the blue, everything came ' back to life '....

Are you an 01491 number, by any chance ??

Yep, 01491....so it wasn't just me then! I wonder how many people it affected. My next door neighbour's connection was fine (couldn't ask anyone else as we don't have any other neighbours). Just double checked - our outage was on Wednesday too, not Tuesday.

One of the ...ahem...'technicians' I spoke to at BT was hopeless. Told me to disable my network card, then asked me if I could connect to the intenet about 30 sec later. Told her that she'd just asked me to disable the card but she didn't seem to understand. Also told her I couldn't see what possible good her suggestions were doing as the problem was on the BT side, not the computer. But there you go, pay peanuts....:ugh:

Thanks Mike Bracknell, will take a squint at that when my brain is more receptive! Are you in Bracknell? How's the Swinley fire fighting going?

I am indeed. We've not seen a lot of it since the roads are closed all over the place, however there's a fair amount of wood burning smell in the air, and the wife's just come back in saying it's difficult to breathe as a result. It was a bit surreal yesterday when coming back from the M3 as it looked like a fresh bit of fire had just caught right next to the motorway as we passed, so it looks like they've got their work cut out. Glad the Harry Potter film seems to have finished filming there too as it might have provided a fair few continuity issues for them if the area on fire is as the rumours suggest. Local paper says a couple of teens have been arrested as a result btw.

Mike Bracknell: Thanks very much for making your powerpoint file available to the rest of us. I found it most interesting.

P.P.

Mike-Bracknell,

I reckon you've posted that Powerpoint before..... :E

Little bit too basic for me, but am sure will be of interest to others as it does to a reasonable job of explaining things quite clearly.

I probably have :)

Sorry I didn't cover more in-depth things, but the point of the PPT was to give people a basic idea of how it all worked - thus hopefully giving them the ability to delve further on their own.
:ok:

...er, thank you for that. Shortly after you posted it I read and digested it. Three days later I failed the test.

Do techie types have different brains compared to others?

Short answer - yes.

Longer answer - it's what keeps us in beer :)