Re: CM700 time mismatch and login issues

raylo32 · ‎2022-08-25

I have been having trouble logging into the GUI for my modem. Lots of page not found and one "unsupported protocol" error. I read about that and it says a time discrepancy could be the cause. I have been able to get in intermittently and I see that the time stamps on the event logs are an hour off from PC and real time. Like it didn't adjust for DST. I also can't find a place in there to set the time. Any help??

raylo32 · ‎2022-08-25

Well, it looks like it was that butt connector... or perhaps just needing to also clean and tighten the ISP side.

First, I connected the ISP cable directly to the modem outside and plugged the ethernet into a laptop. Accessed the GUI and correctables and uncorrectables were 0. So, I installed a fresh new splitter out there to the cable that runs to the network closet and tested similarly in there and success, errors still 0, so my cable is good. Phew.

So, I then reconnected CM700 modem output ethernet to the router to restore my network and everything is working... EXCEPT I can no longer log onto the modem GUI to check or monitor this going forward. On any device, wired or wifi. On any browser. I just get "can't reach page, took too long to respond" errors. Just like it had been for weeks lately until somehow miraculously I started being able to logon this morning. But that is just gone again? I really don't understand what is blocking me from reaching the modem admin GUI.

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FURRYe38 · ‎2022-08-25

There is no time settings on CM series modems.

What browser are you using? Try MS Edge, Firefox or Opera.

If you can get logged in to the CM modem with a wired PC, Please post a copy and paste of the modems connection status page.
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended.

What is the brand and model of the host wifi router connected to the modem?
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router?article=24311
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

raylo32 · ‎2022-08-25

I seem to be able to mostly log on today without too many issues wifi and wired PCs. For the last week I could get in very rarely. Only today on Edge browser I get unsupported protocol. No issues on Chrome. Powers and SNR all within spec. Status shows good.

I am doing this because I have been getting some connectivity issues and dropouts. The CM700 event log showed some "critical" errors, T3 errors.

There is one butt connector between the Xfinity service cable and a cable I have run to my closet where the modem sits and feeds my Linksys 3200ACM router. Can't eliminate that butt connector. In the interim I have cleaned and tightened those connections and reset the event log. Nothing so far.

raylo32 · ‎2022-08-25

Here is the connection and channel info. BTW, I just got another T3 timeout error in the log.

FURRYe38 · ‎2022-08-25

Please post a capture of the Event Log.

You have lots of Correct and Un-correctables that should be all zeros. This mostly comes from bad cabling, splitters or fittings that are not done well or snug. I would check your cabling from the ISP service box to the modem. Remove any splitters and make sure fittings are snugs and cable doesn't have any kinks or sever bends.

raylo32 · ‎2022-08-25

I am suspecting that I may have a bad Comcast service cable. Similar happened once upon a time... But it could also be my coax that feeds my closet that is butted to the Comcast cable. There are no splitters. Just a simple butt connection, one in, one out. I can run a temp coax from this butt connection outside through the door or window to the modem to see if that makes a difference before I call them to come check their cable.

Here is the log file from this morning. I have since cleaned and tightened the outside butt connections but I have had one more T3 timeout since then.

FURRYe38 · ‎2022-08-25

OK, The ISP needs to resolve those Critical messages in the Event log.

raylo32 · ‎2022-08-25

Is there a chance that the modem is failing?

FURRYe38 · ‎2022-08-25

Possible. You would have to try another CM series modem to see if it does same thing or something different. Compare those two log items that you posted.

raylo32 · ‎2022-08-25

Well, it looks like it was that butt connector... or perhaps just needing to also clean and tighten the ISP side.

First, I connected the ISP cable directly to the modem outside and plugged the ethernet into a laptop. Accessed the GUI and correctables and uncorrectables were 0. So, I installed a fresh new splitter out there to the cable that runs to the network closet and tested similarly in there and success, errors still 0, so my cable is good. Phew.

So, I then reconnected CM700 modem output ethernet to the router to restore my network and everything is working... EXCEPT I can no longer log onto the modem GUI to check or monitor this going forward. On any device, wired or wifi. On any browser. I just get "can't reach page, took too long to respond" errors. Just like it had been for weeks lately until somehow miraculously I started being able to logon this morning. But that is just gone again? I really don't understand what is blocking me from reaching the modem admin GUI.

raylo32 · ‎2022-08-25

This is what windows network diagnostics says:

FURRYe38 · ‎2022-08-25

Have you factory reset the modem by pressing the reset button for 10 seconds then release with out the ISP coax cable connected the modem and 1 wired PC connected to the back of the modem?

raylo32 · ‎2022-08-25

No, I am afraid that will cause me to have to call Comcast to redo the provisioning. Don't want to do that. But LOL it just started responding again, who knows why? All errors are zero except channel 1 correctables which is 7. I am ready to call this one solved.

FURRYe38 · ‎2022-08-25

Looks like what you did with that one connector hopefully solved it.

Glad you got it working. Please mark your thread as solved so others will know. Be sure to save off a back up configuration to file for safe keeping. Saves time if a reset is needed.
https://kb.netgear.com/24231/How-do-I-back-up-the-router-configuration-settings-on-my-Nighthawk-rout...
Enjoy. 📡

Kitsap · ‎2022-08-25

Make sure you are not using 192.168.100.xxx as the base IP address for your router. Suggest 192.168.1.1 or 10.0.0.1.

raylo32 · ‎2022-08-26

We'll see. So far so good and the data look stable with few errors. But I did have one T3 timeout in the event log from last night. I'll keep monitoring it. No longer having any issue logging onto the GUI except on one laptop and then only on Edge browser saying "incompatible protocol". Works on Chrome on that PC. Edge browser and Chrome works fine to access the GUI on all other devices.

To answer the other poster, the modem IP is completely out of my router's subnet.

If I keep getting T3 timeouts I'll post another thread to chase that down. So far I have not noticed any more connectivity issues in use. But need more time to see if this is truly solved.

FURRYe38 · ‎2022-08-26

Glad you got it working better. Any line issues and such. Have the ISP take a look.

Enjoy.