NETWORK TOPOLOGY AND HISTORY
I have a long and complex history with ASUS routers, but I will keep this as concise as possible: I have an RT-AC5300 set up as my wifi router, and two RT-AC86U devices serving as Media Bridges (there are Ethernet devices on all three floors of my home). For almost a year I had been running AiMesh until very recently. It was great when it worked, but was very unstable. I had to reboot the main router about once a week to fix internet access problems on the AiMesh nodes.
PROBLEM SUMMARY
So yesterday I performed a hard reset on all three devices and set them up in the 1 router + 2 media bridge mode and everything was fine in terms of internet connectivity and performance (in fact, download speeds are literally 6 times better than when in AiMesh mode), but there was one significant problem: After several minutes online I could no longer access the AC5300's web interface.
No matter which computer or browser I used, whether connected wirelessly or via Ethernet, shortly after the initial configuration I was unable to access the web interface at 192.168.1.1. I knew that was the correct IP address (it is the ASUS default anyway, but also, PC clients showed 192.168.1.1 was the gateway address, with the default submask). NOTE: The web interface DID work for a few minutes. It was long enough for me to enable the Traffic Analyzer feature and begin correcting some client names in the Netork Map page's client list. But suddenly I was no longer able to access the page, and 192.168.1.1 failed to load on any other device. At first I thought it was the issue of one device already being logged in to the admin page, because I did access it from a couple different computers- but even after rebooting the router and the computers in question it still didn't work.
RESOLUTION
On a hunch that it was an address resolution problem, I disconnected the WAN connection to the AC5300 and what do you know- suddenly I can load 192.168.1.1 from my client devices and access the web interface. I went to Advanced Settings > LAN and changed the IP Address setting to 192.168.10.1 and rebooted the router. Clients still have fast internet access and now I can access the router's web interface while connected to the WAN. Problem solved! But...
QUESTION
What the heck happened? 192.168.1.1 isn't a valid IP address outside of a LAN. Why would my clients have trouble resolving that address while connected to the WAN? None of the devices in my home/network have static IPs, and even if they did- they definitely wouldn't be set to 192.168.1.1. (In fact, when I reset the two AC86U routers to factory, their default IP address was 192.168.50.1 until configured as media bridges- which surprised me.) Is a rogue 192.168.1.1 device somewhere between my home and the internet the only possibility? (For what it's worth, I cannot currently ping or browse to 192.168.1.1, so even after resolving the apparent "conflict" I can't find the phantom other device at that address.)
One note in case this matters: Other than the default admin password and the required connectivity/security settings, the only other setting I had changed before the problem occurred was the WAN DNS Setting options. (Specified the OpenDNS server addresses.) I don't see how this could cause the above behavior since DNS isn't used/required when accessing resources by IP address, but it is the only non-essential setting change I made.
I have a long and complex history with ASUS routers, but I will keep this as concise as possible: I have an RT-AC5300 set up as my wifi router, and two RT-AC86U devices serving as Media Bridges (there are Ethernet devices on all three floors of my home). For almost a year I had been running AiMesh until very recently. It was great when it worked, but was very unstable. I had to reboot the main router about once a week to fix internet access problems on the AiMesh nodes.
PROBLEM SUMMARY
So yesterday I performed a hard reset on all three devices and set them up in the 1 router + 2 media bridge mode and everything was fine in terms of internet connectivity and performance (in fact, download speeds are literally 6 times better than when in AiMesh mode), but there was one significant problem: After several minutes online I could no longer access the AC5300's web interface.
No matter which computer or browser I used, whether connected wirelessly or via Ethernet, shortly after the initial configuration I was unable to access the web interface at 192.168.1.1. I knew that was the correct IP address (it is the ASUS default anyway, but also, PC clients showed 192.168.1.1 was the gateway address, with the default submask). NOTE: The web interface DID work for a few minutes. It was long enough for me to enable the Traffic Analyzer feature and begin correcting some client names in the Netork Map page's client list. But suddenly I was no longer able to access the page, and 192.168.1.1 failed to load on any other device. At first I thought it was the issue of one device already being logged in to the admin page, because I did access it from a couple different computers- but even after rebooting the router and the computers in question it still didn't work.
RESOLUTION
On a hunch that it was an address resolution problem, I disconnected the WAN connection to the AC5300 and what do you know- suddenly I can load 192.168.1.1 from my client devices and access the web interface. I went to Advanced Settings > LAN and changed the IP Address setting to 192.168.10.1 and rebooted the router. Clients still have fast internet access and now I can access the router's web interface while connected to the WAN. Problem solved! But...
QUESTION
What the heck happened? 192.168.1.1 isn't a valid IP address outside of a LAN. Why would my clients have trouble resolving that address while connected to the WAN? None of the devices in my home/network have static IPs, and even if they did- they definitely wouldn't be set to 192.168.1.1. (In fact, when I reset the two AC86U routers to factory, their default IP address was 192.168.50.1 until configured as media bridges- which surprised me.) Is a rogue 192.168.1.1 device somewhere between my home and the internet the only possibility? (For what it's worth, I cannot currently ping or browse to 192.168.1.1, so even after resolving the apparent "conflict" I can't find the phantom other device at that address.)
One note in case this matters: Other than the default admin password and the required connectivity/security settings, the only other setting I had changed before the problem occurred was the WAN DNS Setting options. (Specified the OpenDNS server addresses.) I don't see how this could cause the above behavior since DNS isn't used/required when accessing resources by IP address, but it is the only non-essential setting change I made.
