Wifi issues solved by deleting registry subkeys under Tcpip\Parameters\Interfaces but why?

Question

I have a Dell Latitute E7250 with Windows 10 Pro and an Intel Dual Band Wireless-AC 7265 wifi card.

I have constant problems connecting to wifi networks - the laptop either gets stuck on the DHCP auto-config address, or it appears to connect but has no internet connectivity (can't even ping the gateway, let alone DNS or anywhere else). At the same time, my phone will connect fine to the same access point.

I've tried various ways of resetting network settings, but the only thing that works is deleting the keys under Computer\HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Interfaces and rebooting (advice from someone I trust but who was too busy to explain it!) This works for a while, but the problem then comes back after a while as new keys are written.

Can anyone explain:

• what these keys do
• what might be going on here
• is there a more permanent fix
• does netsh int ip reset achieve the same thing without having to mess with the registry?

Answer 1

Answer to question 1:

As far as I know these keys store the network configuration for the DHCP service.The DHCP service normally tries to get a new lease for the ip address it got the last time because then it can reuse the old configuration and it will only request a new ip address if the DHCP server refuses the request.For example the ip address could already be used by another client.

Answer to question 2:

As I said before the DHCP service tries to get the old ip address again and if it gets it the DHCP service will simply reuse the old stored network configuration, but now the problem is that Windows will assume that the ip address is available if the DHCP server doesn't respond in time.So your problem could be a too slow responding DHCP server because Windows will assume that the ip address is available and it will reuse the old configuration even if it isn't valid anymore and so it is impossible to resolve the ip address.

Answer to question 3:

You would need to find out what the issue with your DHCP server is.

Answer to question 4:

No because the command won't delete the old DHCP configuration, but you should be able to reset the ip addresses of the DHCP configuration which will force DHCP to get new ones by executing:
Ipconfig /Release yourinterface Ipconfig /Renew yourinterface

For more information: https://support.microsoft.com/en-us/help/167014/dhcp-client-may-fail-to-obtain-a-dhcp-assigned-ip-address