If you have problems accessing the modem, unplug the power brick from the wall socket, wait about 30 seconds and plug it back in so that the modem restarts. That usually cures the issue with modem access.
Here's a link to the CGN3 manual. The description of the front LEDs is on page 19 and 20. There have been mismatches between the colour of the LED as shown in the manual and that which is observed on the front of the modem. I'm not sure at the present time if that has been fixed. The way to determine the connection rate with a remote device is to look at the back of the modem, specifically at the connected port LED. Amber indicates a 1 Gb/s connection rate, green indicates a 10/100 mb/s connection rate. Those LEDs can be used to determine if you have a bad port on the remote device or a bad connecting cable.
Hmm, tried rebooting the router as suggested and still can't get into it. What's weird is I can get online no problem and browse the internet.
If you have the latest firmware loaded on the CGN3, you should use 192.168.100.1 to access the modem with the modem running in Brige mode and the router in place. Unless you have changed the router's LAN IP address, it would be 192.168.0.1, or possibly 192.168.1.1 I believe the last address is the default for the router.
Some more possible clues I have noticed now:
1) Why couldn't I login to the modem after putting it in bridge mode? Had to reset modem.
2) That green ethernet light has STOPPED blinking now after reset. (not in bridge mode currently). It only blinks eractically if I am browsing websites. I have my laptop connected directly to the modem. (and just my laptop, nothing else).
EDIT: See below, just happened:
3) I haven't done any changes to my Rogers modem, and only have my laptop connected via ethernet since the reset this morning. And the Internet just went out on me. (@ symbole went dark, no connection on laptop).
OK, well, I decided to try and put the modem back into bridge mode. I turned the gateway off, the modem rebooted and that stupid ethernet light starts blinking rapidly again. This has to be some sort of clue, as it doesn't do that when the modem is in gateway mode. I still have my laptop wired to the modem, and haven't plugged in my ASUS RT-N66u to the modem yet.
So, I am going to have to assume it's not my router right now, but still.....I have no idea. And I can't see it being the modem, or I have had 3 bad modems in the past month.
EDIT: Just connected my ASUS, no changes, but the internet is lightning fast right now (until it goes down again). Speedtests are 180+MB/s wired laptop and on my Nexus 6p in the same room as the ASUS.
The signal is within specification so the issue doesn't appear to be signal related.
I see you have tried the modem only before but Im not sure for how long. Can you please use the Rogers modem only with a few devices connected(wired & wireless) & monitor for a few days. If the connection drops, verify if it has dropped on all devices(wired & wireless) & make note of the time it drops / amount of times it dropped during the few days.
Let us know the outcome.
Your downstram signal levels are slightly low, down around -3 dBmV, and the upstream are elevated sitting at around 46 dBmV. Ideally they would be at 0 dBmV on the downstream and somewhere between 36 to 40 dBmV on the upstream. However, where they are now shouldn't be causing any issues.
You're running off of a Casa Systems CMTS which at the present time is causing issues for CGN3ACSMR modems. But, according to your posts, you currently have a CGN3 with Firmware Version 126.96.36.199 which is the latest version. As far as I know, the CGN3 is immune to the issues that are caused by the Casa CMTS / CGN3ACSMR interaction.
The fact that you've had this problem on both modems suggests that there is something else going on that isn't evident in the signal levels. Its possible that there is some intermittent signal issue within the external cable that pops up every now and then. If the cable simply died it would be much easier to trace the problem.
When the modem LAN ports go down call tech support and ask the CSR to run a signal check on the modem. Don't do anything to the modem. Leave it sitting in its "dead" condition. The question at this point is whether or not the CSR can actually communicate with the modem. If not, I would say that there is a cable issue afoot, and the CSR should dispatch a tech to check the cable. If the CSR can communicate with the modem, and the LAN ports are still dead, then I would think there is something else going on. We've seen a handful of cases where the LAN ports or wifi network stops working, and in those cases the problem was caused by a remote device LAN port or remote device wifi adapter. Once those were changed, the problem did not return. In your case you only have the router attached, so, I would try running a different cable between the modem and router for test purposes.
If the problem returned I would return the modem to gateway mode and set it to run as the main router with the wifi turned off. Then, on the router, disable the DHCP server and leave everything else set as it currently is, including the wifi. You can decide to either keep the firewall on the router running or turn it off. It depends on what you have running off of the router in terms of LAN devices, and you might be ok with the router firewall left on. What that gives you is a firewalled network within the larger network. As long as you weren't trying to communicate device to device from one side of the firewall to the other, you should be ok. Save the settings and reboot the router. As its rebooting, disconnect the ethernet cable from the router WAN port and plug it into one of the router LAN ports. When the router has completed its reboot, you will have a wifi access point thru the router with the modem running the network. What this does is take the router WAN port out of the network for test purposes. Run the network in this configuration and with a different modem to router cable, looking for the next failure occurrence. If the failure reoccurs, then neither the cable or router WAN port is at fault. I would look further for an RG-6 cable fault, either internal or external to your home.
Are you in a house, apartment, condo, highrise, etc, etc?