PN BB – Always on, unless it’s intermittent or down completely

[#1]

After years of trouble-free use my problems started on 11th August when sync was lost. This was fixed and access restored on 13th Aug.
Over the next 2 weeks access was intermittent – I’d power up my PC and Netgear router and either had, or didn’t have external access. When available, access lasted from 7 minutes to 23 hours, before suddenly stopping. After the initial fault, sync is always achieved, and I generally obtained an IP assigned, with ‘connection’ stated at around 3800kbps.
When down - CHAP authentication successful but no external access - tracert times-out after the 1st hop.
From 26th Aug to 7th Sep. no BB service was available. On 8th Sep. with no apparent changes, I turned on the PC and router and it all worked – then, 90 minutes later, the connection was suddenly lost again and no further access has been possible since.
I’ve tried 3 routers, 2 PC’s (XP sp3), 1 laptop (Vista). Purchased new filters, new Ethernet cables, disabled then uninstalled security software, re-set routers to factory settings, moved from a static to dynamic IP. BT has fitted a new master socket and checked the line back to the exchange.
Regardless of PC or router, external access is either possible or not. When external access is down, cycling the PC and/or router makes no difference – it’s down for hours or days. Dial-up works fine – albeit at 50kbps
DHCP enabled. Auto-configuration set for IP and DNS.
Line Attenuation = 28 db
Noise Margin = 15 – 17 db (No significant difference on Master or extension)
After countless calls to PN support, a mammoth support log and 2 visits from BT – PN say there’s nothing wrong with the account and suggest another BT visit and BT say there’s nothing wrong with the line and it must be an ISP issue – in the meantime I’ve got no BB access. I’d really appreciate any assistance/suggestions.

[#2]

Can we get some facts
When you get no access is the adsl light on?
What router are you using?
When you connect but cant get out can you do a ipconfig /all from a cmd prompt and post it.
You say you cant get out when connected how does this show its self any error message is it all webpage and email MSN etc or just web pages?
When you are connected and cant get out do a ping 194.119.131.66 and post results then a tracert 194.119.131.66 and finally ping www.plus.com
Can you manually assign dns on your pc to      208.67.222.222 and  208.67.220.220 and see if that helps.
try the usual disconnect all phones and extensions and plug directly into the master socket

[#3]

You say that when access is down the tracert fails after the first hop which should be your router (I use a netgear RangeMax DG834N myself and this IP is 192.168.0.1
When access is not available, what does your router configuration screen say about status? does it indicate that its trying to acquire an IP address?
When you replaced your router did you back up the settings from the old and upload it to the new? If you did are you certain did not inadvertently block everything outbound in the router firewall configuration?
Another thing I did myself while tinkering was to switch off NAT and this stuffed up the connection to servers on the net (switching off NAT means that the router will only route packets over the Ethernet ports and not the ADSL link)

[#4]

Some facts - as requested...
* When I have no access sync is achieved and the ASDL/WAN light is on.
* Router shows connected at 3776kbps and IP assigned
* Main router is Netgear 834gt. Purchased Sitecom DC224 when problems started and have tried an old Origo ASR8400
* When down - IE displays 'looking up www.bbc.co.uk - rather than 'connecting to...' and shows 'IE cannot display webpage - not connected to Internet, website encountering problems or typing error in the address'. Impacts all external traffic - email and webpages.
* Manually setting dns on PC to 208.67.222.222 etc made no difference.
* Connection at Master and extension makes no difference - No access - Noise Margin and Line Atten. the same.
* Will run tests and post results

[#5]

PING 194.119.131.66 (194.119.131.66): 56 data bytes
--- 194.119.131.66 ping statistics ---
4 packets transmitted, 0 packets received, 100% packet loss

[#6]

tracert 164.119.131.66 & ping www.plus.com

[#7]

ipconfig

[#8]

If pinging an IP address doesn't work then it isn't a DNS issue. I'd be tempted to say your router was at fault somehow, either in the connection settings or just faulty, but you have tried three different ones with the same results, yes? In that case I suggest you raise a fault ticket and get someone at PN to look into it.

[#9]

When access not available - Router shows IP assigned, modem status - connected. DS connection speed around 3700kbps
When new router tried it was set-up from scratch. Also tried factory-reset on Netgear and also on Sitecom and it's made no difference.
NAT is 'Enabled'
Netgear log shows
Sat, 2000-01-01 00:05:05 - LCP down.
Sat, 2000-01-01 00:05:13 - Initialize LCP.
Sat, 2000-01-01 00:05:13 - LCP is allowed to come up.
Sat, 2000-01-01 00:05:23 - CHAP authentication success
After around ten minutes, it disconnects, gets a new IP (now dynamic) and starts sequence again.

[#10]

Denzil - Yup, I've tried 3 routers - all achieve sync, get an IP assigned, but none provide external access when connected to any of 3 PC's.
When access is available, any router and any PC is OK.
Problems started 5 weeks ago (11th Aug) and PN have been 'looking into it' since sync was restored on 13th Aug.

[#11]

Ah, yes, should have read your first post more carefully! It does look like something that is outside your direct control i.e. a problem with BTs equipment or with Plusnet. Hopefully someone from the Comms team will see this tomorrow and nudge things along.

[#12]

The only thing I can think of thats left is what is the mtu setting on the router as this could kill it stone dead. try  setting it to 1500 reboot and then drop it down to 1475 and see if it has any effect.
Try seting the router dns to 208.67.222.222 and  208.67.220.220

[#13]

Samuria - I'll check / adjust the mtu and reset to Open DNS and reboot the router when I get in from work tonight.
I'll let you know how it goes.
Thanks.

[#14]

I thought we had already tried OpenDNS?

Quote

* Manually setting dns on PC to 208.67.222.222 etc made no difference.

In any case, the purpose of a DNS server is to take an address in the form www.whatever.com and look up the actual IP address so your PC knows where to find it. This has already been ruled out by the ping test, which goes direct to the IP address without recourse to DNS. Still, the MTU is worth a go.

[#15]

Very odd indeed.
Have you checked your account on the member centre to see if you may have inadvertently gone over your bandwidth/permitted spend limit?
Only one other thing you could try, remove all rules from the outbound section of the netgear firewall (firewall rules from left hand navigation bar in router manager web interface) and then click Apply, then try the ping/tracert tests again.