Laptop not getting IP from DHCP.

[mrwobbly]

I have a teacher laptop which has worked fine for a year. Then since last week it will not connect to the school or home network. The network status stays at identifying network on both wired and wireless.

 

Looking into it, it was not picking up an IP address. Set a static and it worked fine.

I’ve tried a system restore, disabled IP v6, I can count out drivers as it’s happened to both NIC’s at the same time. Network problems are also out as it happens in school and at home. This was a known problem with Vista and Microsoft have a fix-it but the problem was sorted with windows 7.

 

Anybody come across this or have any ideas?

[sted]

try giving it a reserved ip i dhcp ive found the odd laptop that wont pick up an ip will if its a reserved one

[mrwobbly]

That would be fine if it were a desktop but as it’s a laptop, it still would leave it unable to be used at home.

[teejay]

Do an

ipconfig /release Local*

ipconfig /release Wireless*

(don't do ipconfig /release all)

shutdown the laptop and take the battery out for a good couple of minutes

see if that fixes it

[sted]

That would be fine if it were a desktop but as it’s a laptop, it still would leave it unable to be used at home.

 

sometimes once it gets an address from one dhcp server it starts playing ball again with others

[mac_shinobi]

I have a teacher laptop which has worked fine for a year. Then since last week it will not connect to the school or home network. The network status stays at identifying network on both wired and wireless.

 

Looking into it, it was not picking up an IP address. Set a static and it worked fine.

I’ve tried a system restore, disabled IP v6, I can count out drivers as it’s happened to both NIC’s at the same time. Network problems are also out as it happens in school and at home. This was a known problem with Vista and Microsoft have a fix-it but the problem was sorted with windows 7.

 

Anybody come across this or have any ideas?

 

I know with windows 7 the issue should of been fixed but as per another thread it was in relation to the firewall, just curious if you completely disable the firewall and test again, is it the same, also update the network card driver ??

 

Then disable auto sense and manually set the network speed to the relevant speed which I presume would be 100 mbps full duplex ??

[ricki]

HI

 

I know this will be silly questions but here goes.

 

Have you tried a different network cable?

Have you tried it in a different port connected to a different switch?

Have you rebooted the switch it may have crashed or cut off a port as it thinks there is a problem like a loop etc?

Have you updated the drivers for the nic cards.?

Are all windows updates on the computer?

Have you tested the machine for viruses and spyware?

Have you restarted the dhcp server service on the server?

Is the firewall running with a strange setup

Have you run a chkdsk as its strange both wifi and wired are acting the same so might be a corrupt file in the os.

Have you tried a sfc /scannow

 

 

 

Richard

Edited May 17, 2011 by ricki

[mrwobbly]

Thanks for the reply Richard.

 

Have you tried a different network cable?

Have you tried it in a different port connected to a different switch?

 

This is a wireless teacher laptop. I pulled the network cable from a working desktop to test it.

 

Have you rebooted the switch it may have crashed or cut off a port as it thinks there is a problem like a loop etc?

 

If that was the case it would not have worked with a static address.

 

Have you updated the drivers for the nic cards.?

Are all windows updates on the computer?

 

Both cards have worked for a year and then for them both to develop the same problem at the same time. Not likely to be drivers. I will update them Friday.

 

Have you tested the machine for viruses and spyware?

 

See below regarding time limitations.

 

Have you restarted the dhcp server service on the server?

 

I can rule the server out as it happened at home at the same time.

 

Is the firewall running with a strange setup

 

I turned off the Windows firewall to test. The laptop is on an intranet behind a county firewall.

 

 

Have you run a chkdsk as its strange both wifi and wired are acting the same so might be a corrupt file in the os.

Have you tried a sfc /scannow

 

I’m sure it is a problem within windows on the laptop. Something becoming unregistered or corrupt windows file maybe.

 

It’s a small primary and I only visit for two hours once a fortnight. I have no time to run a full chkdsk, virus scan and system file check.

 

I will run through everything everybody has suggested. probably just reinstall windows and get as much software as I can time permitting Friday. Then leave the teacher a list of software and plug-ins he needs to install himself.

Edited May 17, 2011 by mrwobbly

[ricki]

Have you tried a different network cable?

Have you tried it in a different port connected to a different switch?

 

This is a wireless teacher laptop. I pulled the network cable from a working desktop to test it.

 

Have you rebooted the access point and has someone restricted the access point with something like mac filtering or radius.

Does it work with the cable?

 

Have you rebooted the switch it may have crashed or cut off a port as it thinks there is a problem like a loop etc?

 

If that was the case it would not have worked with a static address.

 

This is not always correct smart switches can disconnect single ports. We have had this when machines have spyware or viruses and is spamming the network. I have also had this if the nic or the nic driver is not liked by the switch.

 

Have you updated the drivers for the nic cards.?

Are all windows updates on the computer?

 

Both cards have worked for a year and then for them both to develop the same problem at the same time. Not likely to be drivers. I will update them Friday.

 

That may be correct but windows updates have been coming out and can stop things working.

 

Did it help and are you getting any errors in the event log?

 

Have you tested the machine for viruses and spyware?

 

See below regarding time limitations.

 

Have you restarted the dhcp server service on the server?

 

I can rule the server out as it happened at home at the same time.

 

Is the firewall running with a strange setup

 

I turned off the Windows firewall to test. The laptop is on an intranet behind a county firewall.

 

Sorry I meant the client firewall.

 

Have you run a chkdsk as its strange both wifi and wired are acting the same so might be a corrupt file in the os.

Have you tried a sfc /scannow

 

I’m sure it is a problem within windows on the laptop. Something becoming unregistered or corrupt windows file maybe.

 

It’s a small primary and I only visit for two hours once a fortnight. I have no time to run a full chkdsk, virus scan and system file check.

 

Ask the teacher to run them and tell you what happens on the next visit.

 

I will run through everything everybody has suggested. probably just reinstall windows and get as much software as I can time permitting Friday. Then leave the teacher a list of software and plug-ins he needs to install himself.

[Jawloms]

netsh winsock reset?

[mrwobbly]

netsh winsock reset?

 

Thanks, I've not come across that command.

[mrwobbly]

Just to summarise for any new browsers to the thread.

 

The wired and wireless network cards have stopped picking up an IP address via DHCP both at home and in school.

 

Both nic’s work fine when given a static IP.

[mrwobbly]

netsh winsock reset?

 

Many thanks.

Ran this and an IP is picked up straight away on both nic's.