Internet connection cutting out on W2k

I don't know if anyone can help on this but the situation is as follows... for the last 18 months I have had no problem with my home network - recently the internet connection keeps dropping and nothing has changed other than BT migrating to BT Yahoo - I have called up their helpdesk but, surprise surprise, they were worse than useless...

The set up is as follows:
Netgear ADSL modem connects to the ADSL line
ADSL modem connects into an Actiontec Wireless Gateway
The gateway then connects via cables to a Linux box and the main PC
Two other laptops are then connected via wireless to the network....

the problem is that intermittently, and increasingly regularly I have to turn the ADSL modem off and then turn it on again to get onto the internet... sometimes it can sit idle for hours and stay connected, other times I can be working away and the network will suddenly not be connected to the internet.

All machines are running W2K (except for the Linux box... obviously, which is Mandrake 9.0)

The Internet icon continues to stay lit on the modem even when the connection fails - the LAN icon flashes denoting, presumably a problem
Turning the modem off and on tends to solve the problem in the short term but is becoming a real pain

lots of points on offer since this could take some time to track down!

thanks for your help on this

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wtrmk74Connect With a Mentor Commented:
Hello Again,
To eliminate some confusion from before the [Adapter Id] is not a value to add
you need to find the exact Adapter ID that you need to modify this for
you can locate this information in you registry

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkCards\

for instance
DESCRIPTION           Linksys LNE100TX(v5) Fast Ethernet Adapter
SERVICENAME          35DB7340-3778-4238-B023-D71D9DE46569

this service name is the Adapter ID portion of the registry entry needed

Let me explain.....
now that you have found the unique identifier for your particular card that needs modifying

open regedit and navigate to
locate the SERVICENAME you found from before

now add this value by right clicking on the 35DB7340-3778-4238-B023-D71D9DE46569
and choose NEW  DWORD
type MTU
now double click MTU
type 5d4

here is a list for all DWORD values for the MTU
240  =  576 - Dial-up Connections
5d4  =  1492 - PPPoE Broadband Connections
5dc  =  1500 - Ethernet, DSL and Cable Broadband Connections

here's what the registry file will look like
Windows Registry Editor Version 5.00

remember you can manually add this in or you can add it by using the .REG file here  COPY AND PASTE ABOVE

just edit the SERVICENAME
Just edit the DWORD value\


Hi lz7cjc,

Do you have another ADSL modem you can borrow and test with that?

lz7cjcAuthor Commented:
unfortunately not - have tried changing the filter
any tests I can do on the actual modem to find out if there is aproblem with it?
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Sorry don't know of any.  Maybe some other experts will.

Good Luck

This is a long list, but is SOP for troubleshooting these types of problems..

DSL/Broadband Interference Troubleshooting

The dsl modems usually run at 900 mhz and are affected by other frequency devices. The following should be checked for by removing the possible interference all at once, running the dsl modem connection, and then begin adding items back on - one at a time.

MSNBB: How to Check for Interfering Line Devices(non-public database)

This article describes how to check for and reduce interference on DSL lines. DSL operates by sharing the existing telephone line copper wiring with the telephone service. In this shared environment, any device using the telephone line has the potential to interfere with the DSL connection. The most common interfering devices are:  
-  Telephones: cordless phones that are 2.4/5 ghz can be on the same phone line but not on the same phone/dsl cable as the modem; 900 mhz cordless phones should not be in the same room, sometimes not used at all (dsl modems run at 900 mhz); all phones need to be filtered
-  Answering machines - should be filtered and not on the same cable as the modem
-  Separate Caller ID boxes - should be filtered and not on the same cable as the modem
-  Fax machines - should be filtered and not on the same cable as the modem
-  Dial-up modems - when using for faxing, etc., remove the dsl/phone cable from the modem; the dial up modem can hang up the dsl modem
-  Alarm systems - must be filtered before being attached to the phone line (alarm company is responsible)
-  Digital Cable and TV programming systems, such as TiVO; must be filtered before plugging into the phone line OR just leave unplugged when not using - dsl modem dsl/phone cable unplugged when using systems
-  Digital water or gas meters that transmit data over the phone line - must be filtered
-  Surge suppressors connected to the telephone cable - remove if it cannot be filtered
-  Unfiltered splitters - filter them
MSNBBTS: How to Check for Interfering External Devices(non-public database)

This article describes how to check for and reduce external interference on DSL lines. External interference is caused by devices that generate frequencies used by the DSL line. DSL operates over a series of channels similar to AM/FM radio signals. These channels run between 4 kHz and 1.1 MHz. Any device that emits a frequency in this DSL range can cause interference. The most common interfering devices include:   Cordless phones
-  Sprinkler systems - inside (filter if connected to phone line); outside (if phone lines are above ground, no problem; if buried, have phone company mark where they are buried and turn sprinkler system on to determine if it's flooding over the area where the wires are buried)
-  Radio, TV or cell phone towers within a 1 1/2 mile radius - nothing you can do here, except go back to your cable, which is unaffected for frequency
-  Halogen lamps - remove from same room as modem
-  AM radios - remove from same room as modem
-  Twisted cables (where phone cables from the modem are twisted with other wires such as power cables, printer cables, or powered cabling) - leave hanging free
-  Cable additions - use only the cables provided with the dsl modem; for MSN provided modems the length is 6 feet; adding connectors, extra cable, splitters, etc. can actually disconnect you
-  Ham radio operators - nothing you can do about this either
-  Other radio frequency devices
lz7cjcAuthor Commented:
thanks - the only possible one that could have been effecting this is a cordless phone - however this has been plugged into the same filter as the modem for the last year without any ill effects. Indeed i unplugged it anyway but the problem still occurs

Fatal_ExceptionConnect With a Mentor Commented:
Perhaps it has to do with your MTU size..  ADSL usually requires some overhead if you are using PPPoE..  Try this links and see if they help..
lz7cjcAuthor Commented:
I have searched the registry and I have no entry for
System Key: [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\
Interfaces\[Adapter ID]]
Value Name: MTU
Data Type: REG_DWORD (DWORD Value)
Value Data: Default = 0xffffffff

have not added to the registry before manually - do I need to add this? how would I do this?
Yes, you can add this to your registry...   But..  be sure to backup your registry first..!!  This can be done via ntbackup, backing up your System State...  or..  navigate to the key you are wanting to modify. Once there, right click the key in question, choose Export. Name it according to the edit you are going to perform ending with (ex) xxx_backup.reg.

Then..  perform the operation to create a New MTU value...

Once you locate your adapter, just right click on the Adapter ID and then New > Dword Value..  Then on the right hand screen, right click the new entry and Modify it to your new value...

Question you asked from before,
"is the 1492 a decimal or hexidecimal value"

the answer is DECIMAL

the both represent the same thing

5d4 is the same representation in HEXIDECIMAL

Hope that helps,
Hows this going !
lz7cjcAuthor Commented:
sorry I am currently on holiday so will pick it up on my return
Surprised you even answered if you are vacationing..  :)

Till you get back then..

lz7cjcAuthor Commented:
I am back ... and after struggling to remember what this was all about I think the problem is now resolved
I have replaced the computer i was using with a new one and the problem seems to have gone away

however since you were both so helpful i will reward points anyway :-) split between the two of
A new computer will do wonders..!!  :)

and thank you...

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