Hello all…
So i keep having issues with my basic router, nothing fancy. TPlink, Dlink…
If a device connects to it the device ends up with a subnet mask of 255.0.0.0 when the router is definitely set to IP range 10.1.1.1 and 255.255.255.0
Tried different routers, tried default settings cant think what else it might be. Yes its set to DHCP and gives out IP addresses no problems to devices connected to it. But always sets them as 255.0.0.0 so it connects to the local lan but wont let the internet to connect to the device.
So if i walk away from my home with my mobile all working on wifi and then come back inside again it comes back with a new IP with the subnet 255.0.0.0 so it says connected but no internet…
What am i doing wrong here, its not the router what else could it be? Or maybe i should just set the router to 25.0.0.0? And its just started happening a couple weeks ago, everything was running fine then one day band nothing would connect.
If i set a static IP address the device keeps working perfect, it just does it when its DHCP.
Thanks all
It’s possible that you have a rogue DHCP server on your network.
There’s a really old tool from Microsoft that I’ve used. You can download it here - https://www.tachytelic.net/2019/05/detect-rogue-dhcp-server/
When I tried running it on my computer, it generated an error (couldn’t find
C:\windows\system32\wellknownservers.xml, which is OK) and was able to click Continue.Once the app is loaded, click on the Detect Rogue Servers button.
All the found servers will be “rogue” according to this app, because this was designed to be used in an Enterprise environment with Microsoft DHCP servers have to be “authorized”. But this is strictly a Microsoft concept.
If you have more than one DHCP server showing up, that’s your problem.
You’ll have to hunt down the other DHCP server in your network and disable it.
Thanks heaps, i dont see how i could have a rogue dhcp server on my closed single router system, but ill give it a go. Thanks