[neil.knapp]

Hello all,

I ran into an issue - "The data is invalid" - with devices failing to get addresses via DHCP (dnsmasq) on my router and wasn't finding anything online to help with fixing it so i'm posting my solution in the hope it might assist others.

tl;dr - Set a Domain Name under "Setup -> Basic Setup -> Optional Settings -> Domain Name". I've used "lan" (Apparently best to not use "local" as this is a reserved domain in some scenarios)

DHCP suddenly stopped working for my Windows 10 devices but worked perfectly for everything else (Android phones, Smart TV, Printer).

I don't know whether I can put this down to updating all my Windows 10 devices to 1909 or having moved from an ADSL connection using PPPoE to a fibre connection using DHCP for the WAN, I did both at the same time so can't confirm which was the cause and i'm not rolling back my Windows boxes to find out.

If a domain isn't configured on dd-wrt Windows 10 will silently assign an APIPA address and state "Connected, No Internet". If you release and try to renew via ipconfig it will give an error of "The data is invalid" for the interface it's trying to assign.

You can assign a static IP and things will work but a domain name has to be assigned for DHCP to work properly. I don't know if this is specific to dnsmasq, I didn't try dhcpd.

My router: TP-Link TL-WR841ND v9
Build: DD-WRT v3.0-r42819 std (03/30/20)

There is another post of someone encountering this error and they suggest adding the "dhcp-broadcast" option to the dnsmasq services but that didn't solve anything for me. (https://forum.dd-wrt.com/phpBB2/viewtopic.php?p=1175942&sid=fe62802974c7acb9afcfed57a802106e)

I hope this helps someone.

Regards,

[kernel-panic69]

Thank you for posting. Considering this, I may just take the plunge and do some backups and convert one desktop to Debian 9, and the other to Ubuntu 18.04 and toss M$ sh*t for good. Also, to note, this may have also been tied to issues in dnsmasq that may have since been patched, so if it's still an issue on more current releases, then it could be either or (but more likely it's M$ junk).

EDIT: udhcpd is no longer included in this firmware. Also, not sure how the rest of your network configurations are, but there's the possibility that it was something else of conflict causing the issues.

[Alozaros]

hmm had something similar on W10 1909, but...as it says its not connected... once i start browser its ok and than connects... had to go trough all my firewall rules to find out witch interferes, sadly non of them was doing wrong...interesting, once connection goes idle it says not connected, until there is an event like browser or app tries to connect...so far its fine but it does that shit...

KP69 if you want decent linux..try parrotOS..very compact n sequre, useful, packed with apps that you will like it... compare with Kali, Black Arch, Tails much easy to understand and use....

[kernel-panic69]

[Alozaros]

'Turn off all power-save features' 10x for the advice i never have those on anyway..i believe it's an Win 10 shit
i tried various solutions, no avail yet, the fact its working its ok...
interesting issue i have as well is on my Win 7 Ultimate, has the same DHCP issue with new connections, all those that are already there are fine, but for any new i have to take f-wall down to make it happen or add a static values...those happened somewhere around the of last Win Updates..mid last year...