[SOLVED] Default gateway erased/reset/lost on reboot

[lordvj 0]

Ok so as the title says , my tcpip default gateway gets reset on reboot , i have to manually set it again for my connection{static ip} to work.... Googling has not helped , i've tried everything - reseting tcpip , winsock , drivers - old and latest, meddling with the tcpip /interface registry entries , a win7 x64 clean reinstall fixed the problem for a while but it popped back suddenly and i cannot find the cause for it .

Someone please help me out . thanks

[TechyAdmin 0]

Hi,

As per the issue description and the steps you mentioned, i seems you have tried all possible steps to fix the problem. Here is what i will suggest and that should fix the issue.

On the problem machine, Expand to following location in registry editor.

HKLM__System__Current Control Set__Control__Network

In the right side pane, there is a REG_BINARY key named "Config", delete this key and reboot the machine and it should fix the problem.

Note : Its highly recommended to take the back up of the registry before you make any changes.

Thanks,

TechyAdmin

[lordvj 0]

Thank you for the quick response, however deleting the key did not fix the problem :(

good first post btw

[+BudMan 3,736]

to be honest I find this a little hard to believe.. So for example your static set a lets say

192.168.1.100

255.255.255.0

192.168.1.254

And your saying the 192.168.1.100 and the mask stay but your gateway is gone? Is it all zeros? Just empty, what?

On your advanced IP setting do you have multiple IPs or multiple gateways setup? How many nics do you have in this machine? Do you have a wireless card as well as your ethernet? Are you connecting to multiple networks at the same time? 2 wired, wired and wireless?

You must have something on boot that is trying to set your IP, do you have any 3rd party software for location based IP settings running? What happens when you boot into safe mode with networking?

[lordvj 0]

Exactly and only the gateway is gone. Its just blank [not 0.0.0.0 ] in the tcpip settings. I'm using single IP ,single gateway , 1 nic , connected to only 1 wired network, no wireless , no 3rd party apps and

same problem with safemode with n/w.

[+BudMan 3,736]

So your saying it keeps your IP and mask -- just the gateway is missing? That makes no sense what so ever.. Are you using IPv6?

Can you post the output of your ipconfig /all before you fix the gateway issue.

[TGT 0]

I wonder if you're having a similar issue as this individual had: Fixing connection issues when 0.0.0.0 is set as the default gateway?

[lordvj 0]

Using IP4 .. heres the output from ipconfig

Ok this is just after I reboot

this is after a few second it gets the auto configuration ip , however DHCP is disabled , I tried to disable autoconfiguration IP using this registry key ,but it doesnt seem to work

Parameter: IPAutoconfigurationEnabled

Type: Reg_Dword

Value: 0 or 1

Key: tcpip/parameters for all NICs

Key: tcpip/parameters/interfaces/interface for that NIC

this is after I set my gateway , all normal.

@TGT: Not really ,I removed adobe pdf reader just to check . no luck

[+BudMan 3,736]

where is it getting the opendns servers for dns from if its using APIPA?

When you set to static IP vs dhcp, are you and admin account? Do you have UAC enabled?

Autoconfiguation is different than dhcp. And where exactly is the dword you setting?

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<Adapter GUID>

Note The Adapter GUID subkey is a globally unique identifier (GUID) for the computer's LAN adapter.

Specifying a value of 0 for IPAutoconfigurationEnabled DWORD

So once you set this and reboot -- and you go back into the registry is it still set?? If you have that set in the correct place an ipconfig /all is showing its still enabled - then something wrong with the as far as permissions, or if missing something over writing the key, etc. etc. once you set a static it should be in the KEY. example

Seems like to me your key is not being saved with the setting, or something is over writing it on reboot, etc. So look at your key after you make your static settings.. Now reboot, what is shown in the key? You can view exactly what the guid is for your interface with the

C:\Windows\system32>net config rdr

Computer name \\QUAD-W7

Full Computer name quad-w7.local.lan

User name <snipped>

Workstation active on

NetBT_Tcpip_{85B20B24-8E34-4B9F-B804-B9FE8BE17F9B} (00219B03ACA7)

Software version Windows 7 Ultimate

Workstation domain LOCAL

Logon domain quad-w7

COM Open Timeout (sec) 0

COM Send Count (byte) 16

COM Send Timeout (msec) 250

The command completed successfully.

edit: you most likely need to be running from an elevated prompt for the net config command to work.

[lordvj 0]

Ok I entered that dword value into the interface key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<Adapter GUID>

and apipa is now disabled. i'm on a admin account and uac is disabled .

Gateway is still erased on reboot. I thought it was the permissions too , I verified the permissions to the TCPIP key and it was proper.

and btw there's only 1 subkey - guid in interface key and all the arrowed-entries are present

[+BudMan 3,736]

So you seeing the gateway get placed into the key when you set it using the adapter config gui, and then when you reboot its gone??

Makes no sense -- you have to have something doing a config of your adapter on bootup, or importing the key settings, etc. Very Very ODD!!

You could to monitor your reg and see what is making the change.

http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx

[lordvj 0]

The 'DefaultGateway' registry entry doesnt go away on reboot.

[+BudMan 3,736]

So its there, just not getting read?

I would do a full reset of the your ip stack

netsh int ip reset

You will elevated prompt to do this.

edit: ah I see you stated you did this? "reseting tcpip" Is that command you ran?

Hey for grins -- take a look at your gateway reg key, does there happen to be a blank line above your gateway IP?

Edited August 9, 2010 by BudMan

[lordvj 0]

yes thats the one!

[+BudMan 3,736]

I edit my post -- take a look at your actual value for your gateway -- does it have a blank line above it? Or a space before the first number

[lordvj 0]

Holy crap! I Just noticed my defaultgateway key was a single string REG_SZ as opposed to REG_MULTI_SZ in your screenshot . omg the smallest of things , i'm gonna reboot n check it out

edit: nope , didnt work , i thought there was a breakthru here lol

[tch1005 1]

Holy crap! I Just noticed my defaultgateway key was a single string REG_SZ as opposed to REG_MULTI_SZ in your screenshot . omg the smallest of things , i'm gonna reboot n check it out

edit: nope , didnt work , i thought there was a breakthru here lol

This might work - Doesn't solve the root problem, but is a patch to hold it together, why not have a script launch at Start up to automatically change the Gateway from ___.___.___.___ to the address you want.

[lordvj 0]

I guess i'll have to settle for that.. and btw there were no gaps or spaces in the defaultgateway key.

[lordvj 0]

Its fixed finally , I performed all steps once again and manually created the REG_MULTI_SZ key for the IPAddres and now its all good. Thanks for the support.

[+BudMan 3,736]

Does not make any sense that it would of been a REG_SZ?? Some software must of jacked that up?? I have even looked at my XP box and its a REG_MULTI, very strange...

[1WayJonny 26]

I had just noticed from you screenshots that the subnet mask does change as well.

255.255.0.0

&

other screenshot says:

255.255.255.0

Not sure if this was a onetime typo but just a note FYI

** EDIT **

I have seen this one time before while doing support to the clients network now that I am thinking about it. Ill ask around the office.

1) Have you changed your router or router firmware recently?

2) Which router and model + firmware do you have?

3) Do any other device experience this issue? Laptops? XBOX? Phones?

** EDIT 2 **

It was solved by the time i hit submit , ignore my stuff

[+BudMan 3,736]

Since he is setting his IP static -- does not mater what router or dhcp server he might be using, since this would never come into play at all. As to the netmask changes you saw.. Those were from APIPA which defaults to 16bit mask, that was not him setting his IP or mask.