dimah

New Member
Joined
Nov 2, 2011
Messages
12
Hi all,

We're pretty much stumped as to why we're having this problem.

We've been with our ISP for nearly 2 years without this problem, and about last week suddenly 2 of the 5 desktop PCs on the network suddenly developed the local internet access issue. 3 of the 5 desktop PCs use ethernet/wired, 2 of the 5 desktop PCs use wireless N. The problem seems to happen equally to wired or wireless PCs.

The problem is intermittent, it has since happened on 4 of the 5 desktop PCs on the network.

The problem "symptoms" go roughly like this:
-The affected PC will stop loading web pages (in any browser) message: cannot load web page. The network adapter will STILL think it has internet access.

OR
-The affected PC will stop loading web pages (in any browser) and the network adapter will show local only.

The PCs have shown a range of problems and I believe we've tried most of the fixes out there.

- Enabling/Disabling the adapter will sometimes work. Most of the time it will not work and there will be no internet access.

- Pinging google.com or an address will sometimes work but mostly cannot reach it.
- ipconfig /renew /release /renew6 /release6 etc will sometimes work after multiple attempts and a reboot, but often gives the error "cannot find file.."

- flushdns will complete but doesn't bring back internet access.

- rebooting the modem router will sometimes work, sometimes not. Sometimes it will bring but access on ONE PC but NOT on the other.

- rebooting the PC - same as the router.

- checked for the bonjour / id string service, only one of the PCs has this service and it is disabled anyway.

- Tried the Vista reg fix for forcing DHCP broadcast. Worked on one of the wireless PCs, but the next day after turning on the PC the intermittent/local only was back.

- We have tried 4 different modem routers. ISP provided (thomson BEbox), Belkin modem router F5D8633-4 (we used this one for 2 years+ and never had a problem), and 2 new Belkin F5D8635-4 v1

- We rang our ISP who told us there were no problems detected, they also said they did a 24hr line test and it was fine.

-We've tried setting Google public DNS on all the PC network adapters and the router and the intermittent internet still occurred.

- Tried disabling ipv6 and problem still occurred.

- Checked windows update for recent updates but the only thing prior to the problem was an Microsoft Security Essentials Client update - tried disabling Windows Firewall and MSE and still no access

- Tried updating the wireless driver on one of the PCs that lost access, made no difference.


Our setup looks like this:
Modem Wireless Router --> 2 wired desktop PCs, 1 TP-Link wireless access point --> 1 wired desktop PC, 2 wireless PCs.

All computers are Windows 7 ultimate 64bit

All the computers are custom builds.

I have a Samsung Windows 7 starter netbook which I occasionally turn on and connect wirelessly - have not yet experienced intermittent internet with this.

We are really pulling our hair out here! Not sure why we have been able to use the net for years and suddenly almost all computers on the network have this issue! Sometimes at the same time, sometimes independently. Internet can suddenly drop on one or two PCs just by loading google (router internet lights still on)

Since all the PCs are custom built I'll have to go dig out the motherboard model nos and so on but my PC is:
AMD PhenomII x6 core
6GB ddr3
primary hdd: 500gb sata, x1 seconday hdd: 250gb
mobo: Gigabyte GA-880GMA-UD2H
Ethernet: Realtek

Sorry for the super long post, just trying to put all the info I can think of that might be needed. Many thanks in advance if you can suggest why this is happening and what exactly could be causing it since we've tried changing multiple routers and the problem is happening on more than one PC...

I've tried to list all the "fixes" I've attempted and think that's all of them, but I might have missed one or two and will probably be trying any more that I come across.
 


Oh - just thought to add. Our ISP uses a Dynamic/Fixed IP connection type.
EDIT: Also forgot to add we have tried turning off power saving mode on adapters, no difference.
 


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The way you tell it, sounds like something started effecting your computers and spread. Have you checked which Windows updates have been installed on the bad machines vs. the good one?

Any Anti-virus scans so far? If MSE hasn't found anything, you might try something like Malwarebytes to check one of your bad systems. MSE doesn't show anything in the history?

Any error or warning messages in the event viewer.

Don't know if turning on the Firewall log would help, but you might do that eventually.

Not really sure what a Dynamic/Fixed connection is, but Trouble will probably know.
 


Hi saltgrass, thanks for your reply.

I've set an updated malwarebytes scan running as we speak. Will set them going on the other PCs tonight.

I suppose it does sound like a condition that's spread from one PC to all the rest, but I've never heard or come across this before, is this possible?

Looking in the event viewer, there are a LOT of warning event IDs 1014.
Description: "Name resolution for the name teredo.ipv6.microsoft.com timed out after none of the configured DNS servers responded."

teredo is most common but there are a few random URLs in there. I assume these were created when trying to test the connection working after its dropped out..?

I'll post info on the Malwarebytes scans when they're completed.

Many thanks
 


Look closer at DNS and any global changes made to the network

It sounds like you have performed some rather thorough network testing. I would still recommend checking the DNS on the router in the event that there is a problem resolving hostnames. This problem would be associated with intermittent outages from the ISP's domain name services.

As others have alluded to, you should really check to see what kind of changes were made to your network, server(s), software, or hardware around the time that this problem started.

Resource usage should be easier to monitor for the troubled systems usingthe built in resource monitor. This can include checking specific network utilization.

You should rule out a DNS related issue by running your own DNS server and namespace/zones if this is a production network, alternating the router configured DNS to IPs 8.8.8.8 and 4.4.4.2 (these are trusted, public servers).

When the problem occurs, use this opportunity for intensive network diagnostic testing on the problem systems. This can include trying to ping and/or pull up sites via IP only as opposed to DNS. Poll for errors using traceroute.
 


Hi Mike, thanks for your reply.

2 of the PCs turned up clean on the malwarebytes scan. So although I haven't run full scans on them all yet I think that rules out the malware idea.

I left my PC on all night and this morning I turned on my monitor to find it had dropped internet connection again. This time the yellow exclamation mark over the adapter was not there; Network & Sharing reckons it had full connection. The browser (Firefox) would not load any pages.

I tried pinging a couple of things before I enable/disabled the adapter.
Also, yesterday I found a #2 and #3 isatap adapter hidden in the device manager, both of which I uninstalled. The ipconfig lists it trying to connect to one? Did I read that right?

We have set the router DNS to google's public DNS and on each adapter on each computer, and the problem still occurs intermittently.

As for any hardware/software/network changes - there really haven't been any made at all. This was the first thing we tried to triple check so we could revert back. But nothing was changed - we came downstairs one morning and the 2 wired PCs connected to the Belkin were not loading web pages. We assumed it was time for a new router change, but about 3 routers later the problem remains the same.

Honestly I forgot all about the resource monitor; I will keep that running in the background and check it next time the problem reoccurs.

I should have done as you said this morning and pinged via IP.. will do that next.

Below is the ipconfig from this morning when my PC wouldn't load webpages:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\Anivy>ping 192.168.2.1

Pinging 192.168.2.1 with 32 bytes of data:
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64
Reply from 192.168.2.1: bytes=32 time<1ms TTL=64

Ping statistics for 192.168.2.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

C:\Users\Anivy>ping 8.8.8.8

Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=21ms TTL=54
Reply from 8.8.8.8: bytes=32 time=22ms TTL=54
Reply from 8.8.8.8: bytes=32 time=21ms TTL=54
Reply from 8.8.8.8: bytes=32 time=21ms TTL=54

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 21ms, Maximum = 22ms, Average = 21ms

C:\Users\Anivy>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : Anivy-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : Belkin

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : 1C-6F-65-8B-93-04
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::cc83:612c:92a:d19f%10(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.2.2(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 02 November 2011 16:47:47
Lease Expires . . . . . . . . . . : 01 November 2012 22:47:47
Default Gateway . . . . . . . . . : 192.168.2.1
DHCP Server . . . . . . . . . . . : 192.168.2.1
DHCPv6 IAID . . . . . . . . . . . : 236744549
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-15-2F-FC-7C-1C-6F-65-8B-93-04

DNS Servers . . . . . . . . . . . : 192.168.1.1
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.Belkin:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Reusable ISATAP Interface {45D298A6-DE6F-498F-A52F-B4A70D5047E6}:


Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
 


DNS server is showing 192.168.1.1 -- should it be 192.168.2.1?
 


Thats strange? Our router IP is 192.168.2.1 and the ISP's DNS is meant to be 87.194.255.155

Also, we tried a Vista Home Premium 32bit laptop on the network today and it's showing the same intermittent internet issue. Its creating new networks on the wired adapter and then once you set Home/Work/Public type it will start working.

Could our ISP have changed something that could be causing this? I just can't understand why this is happening on ALL PCs on the network even after changing the router!
 


Just tried another ipconfig /all and a tracert while the internet was loading webpages ok.
I've never really deciphered a tracert before could someone tell me how mine looks?

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\Anivy>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : Anivy-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : Belkin

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . : 1C-6F-65-8B-93-04
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::cc83:612c:92a:d19f%10(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.2.2(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 03 November 2011 11:38:24
Lease Expires . . . . . . . . . . : 02 November 2012 17:38:23
Default Gateway . . . . . . . . . : 192.168.2.1
DHCP Server . . . . . . . . . . . : 192.168.2.1
DHCPv6 IAID . . . . . . . . . . . : 236744549
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-15-2F-FC-7C-1C-6F-65-8B-93-04

DNS Servers . . . . . . . . . . . : 192.168.2.1
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.Belkin:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Reusable ISATAP Interface {45D298A6-DE6F-498F-A52F-B4A70D5047E6}:


Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : Belkin
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

C:\Users\Anivy>tracert google.com

Tracing route to google.com [209.85.169.147]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms 192.168.2.1
2 * * * Request timed out.
3 * 15 ms 15 ms 10.1.3.178
4 17 ms 17 ms 17 ms 10.1.2.158
5 * * * Request timed out.
6 14 ms 14 ms 14 ms 64.233.175.27
7 17 ms 16 ms 16 ms 209.85.253.94
8 23 ms 21 ms 22 ms 72.14.232.134
9 20 ms 20 ms 20 ms 209.85.250.161
10 21 ms 23 ms 25 ms 216.239.43.62
11 21 ms 20 ms 20 ms bru02m01-in-f147.1e100.net [209.85.169.147]

Trace complete.
 


You trace looks OK to me, but I don't have the experience some others do.

Changing a Router might cause some of the symptoms you are seeing. Have you ever been to the router interface to see what it is showing. Normally the WAN DNS addresses are kept there.

Your firewall uses different settings for different types of network. If you change the network type, security will usually be different for sites. Your Home Network should be a Home Network, and not public, unless there is something about your system that requires it. Maybe Mike will know.

It also seems the connection is not your problem, but the DNS situation. If you find some website you cannot connect to or looses the connection, there are ways to determine the IP address and you can use that to check.

Has the question about cloning a MAC address ever come up?
 


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Having similar problems - see my post under "Multiple Network Adapters."
And you are right... it is only by luck when changing some property in the network settings or just turning everything off for a while that you can somehow gain access to the internet again. Very frustrating. I have 125 XP based systems with all the same hardware and they work just fine... it is only the newly installed Win7 units that give me this trouble and I am seriously thinking of rolling those back to XP as I cannot afford the time to look for a workaround. I would lay odds if you put an XP based workstation in the same enviroment you would not have this problem. I understand from one of my vendors that MS overhauled the "networking" section in Win7 and it resulted in the vendor having to change a lot of their code... hearsay I might add but seems the proof is in the pudding.
 


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