Managing your router through the browser

If you’re someone who is into tech and likes to tinker, there is a high chance you use the web console that comes with your router to manage the device, update and set settings.

This is all well and good until you can’t get to it…..

This was my problem today. 😟

The perplexing moment

The moment I tried to browse to the address on another device, I could.

Which isolated the problem to just the PC.

I tried all the things I know from, rebooting the router, making sure the address had “https” before it, temporarily disabling firewalls and making sure I wasn’t being a mong by putting the wrong address in.

Sure enough, I wasn’t.

So what was it?

It turns out I had a duplicate IP…. The duplicate IP address wasn’t something actively being used in the network, other than for the default gateway, and it was a private address (RFC 1918) which typically means it’s unique within the local network.

The duplication was coming from a virtual network adapter that I had been using on some VMs, which I’d long forgotten about. I’d never have considered this to be the reason why I couldn’t get to my management interface because the VMs were powered off, so it shouldn’t have been fighting to keep the IP address.

But because it was directly connected to an interface on the computer, it took priority and traffic was routing to that interface and not the default gateway, which was my router’s management GUI.

I disabled those interfaces and then sure enough it worked, I could browse to my routers control panel.

TIL

Make sure you know what networks and interfaces you have around you, to avoid accidental duplicate IP addresses.