Strange home network problem
November 8, 2017 5:48 AM   Subscribe

Some browsers cannot connect to my router admin page at 192.168.1.1 but others can. Why so and can this be fixed?

Not long ago we had Verizon Fios installed. It was originally set up with the Verizon router. I replaced that with our Asus router (cloning the MAC address) and apart from this odd problem everything worked fine. That router died so I replaced it with a newer Asus RT-AC3200 which also works fine except…

With the new Asus router, trying to connect to the router admin page with my regular Mac at 192.168.1.1 using either Chrome or Firefox gives a blank page with the title “Verizon Router” and what I take to be some Javascript when I view the page source. Where is this coming from? I had the same problem with the old router using Chrome.

I can connect to the router normally using Safari on the Mac, or using a Windows machine with Chrome, or iOS Safari. The Mac is MacBook Pro, early 2015, running Sierra 10.12.6. Oddly I seem to recall that Firefox worked to connect to 192.168.1.1 when using the older Asus router but it doesn’t with the new router.

Admittedly this isn’t a big problem but I am curious as to the cause.
posted by exogenous to Computers & Internet (12 answers total) 1 user marked this as a favorite
 
Do you have any browser plugins installed/configured? I have found a privacy-related one prevented content on a page and/or a redirect from a router page from showing up before.
posted by notorious medium at 6:38 AM on November 8, 2017


Response by poster: I tried running Chrome with the flags for no extensions and no plugins and there's no change. Interestingly if I try with Chrome in incognito mode, the page source is different and much shorter with a reference to a script "top.location.href='/Main_Login.asp';"
posted by exogenous at 7:04 AM on November 8, 2017


Is it possible you have multiple devices that are all responding to 192.168.1.1 (a very common default) and they're stepping on each other? For example, a WiFi access point is going to get dibs on all the traffic coming through its antennas, even if you intend for it to forward the packets through to the cable modem?

If you have ethernet ports on the devices you want to configure, a reliable approach is to start out with a hard-wired connection, then use that to set the admin website IP to something unique to each device (192.168.1.1, 192.168.1.2, 192.168.1.3, etc.)
posted by spacewrench at 8:10 AM on November 8, 2017


Response by poster: I don't think so, just running the one router and no access points or anything like that. And the problem seems reliably specific to the two browsers on the one computer.

Regretfully I don't have the adapter required to connect an ethernet cable to the mac but fortunately accessing the router using Safari on the machine works fine.
posted by exogenous at 9:45 AM on November 8, 2017


Best answer: Sounds like you’re seeing the admin page for the Fios ONT some of the time.

What happens if you ping (or traceroute) to 192.168.1.1 ?

You could try changing your wireless router to a new internal IP address range & give it an internal address in that range ( 10.0.0.0 - 255 say, with the router at 10.0.0.1) and see if that solves the problem.
posted by pharm at 10:21 AM on November 8, 2017


Response by poster: pharm, you're onto something. The 192.168.1.1 address answered pings from the Mac and traceroute answers with the model of the router.

Anyway I changed the IP address of the router and can now reach it from Chrome on the Mac! I'm still curious why those two browsers would try and talk to the ONT instead of the router if anyone has any ideas.
posted by exogenous at 11:21 AM on November 8, 2017


Is that ONT visible on the public Internet? If so I'm wondering if some computers are getting routed through to the outside when trying to connect to 192.168.1.1.

If you really want to figure this out it'd help a lot to know the exact addresses and subnet masks for each of the computers trying to connect.
posted by Nelson at 1:02 PM on November 8, 2017


Response by poster: Is that ONT visible on the public Internet? If so I'm wondering if some computers are getting routed through to the outside when trying to connect to 192.168.1.1.

Hmmm. I looked up my home network public IP and I can ping it from home but I'm not knowledgable enough to know if that's meaningful.

If you really want to figure this out it'd help a lot to know the exact addresses and subnet masks for each of the computers trying to connect.

Even when the issue is per browser and not per computer? The only computer with the problem has Safari, ping, and traceroute work just fine to the router at 192.168.1.1, only Chrome and Firefox act weird.

Anyway I have gone back to a more vanilla setup having the router at 192.168.1.1 with subnet mask 255.255.255.0. The clients are all 192.168.1.whatever, the Mac with the weird browser issue residing at 192.168.1.251.

FWIW, here is the source of the blank page that comes up when I try and access the router using Chrome on the Mac. It seems to have some browser detection stuff? Also, this persists through a reboot.
posted by exogenous at 1:19 PM on November 8, 2017


Oh I missed that two separate browsers on the same computer had different behavior. There goes my subnet routing theory :-/

One other thought is you should pay attention to http:// vs https:// and redirects. There's a problem in how routers work on 192.168.1.1. They can't get a properly signed SSL certificate for https, but sometimes redirect from http to https because otherwise the browser throws up a bunch of security warnings when you submit a form. I've always seen this manifest as browser warnings (like the router offering a self-signed SSL cert that you have to accept) but maybe it causes some weird behavior where you're getting something from cache, or getting data from a device you aren't expecting? It seems unlikely TBH.
posted by Nelson at 2:33 PM on November 8, 2017


Response by poster: Thanks Nelson. Playing around some more, seems like the router admin page won't accept https. Another clue I've just discovered is that Firefox Private Browsing goes to the router admin page even though regular Firefox doesn't. Weird stuff. Anyway I appreciate all the answers - I don't view this issue as much more than an intellectual curiosity and educational experience so I'm not too concerned, just intrigued.
posted by exogenous at 2:47 PM on November 8, 2017


Best answer: Well, if you really want to track it down still, use tcpdump to monitor the actual traffic when each browser tries to visit the router. I'm pretty sure that a Mac has one or the other installed already, at least my laptop running 10.11 does.

You will have to read a bit about options and things ("man tcpdump"), but you can save a couple of log files and then experiment with dumping them in various formats. There will be LOTS of information and there are a lot of different formats. The "-vvv" switch is your friend.

Or, if you are not that old school, you could use wireshark, which is more of a GUI thing, but you'd probably have to install it. It might be much more trouble than you want to take, though.
posted by Gilgamesh's Chauffeur at 7:44 PM on November 8, 2017


Response by poster: Thanks, I messed around a bit and it's all pretty cryptic for the time I have this morning but I hope to try this later.
posted by exogenous at 4:24 AM on November 9, 2017


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