I've been using DD-WRT for a pretty long time (since arond 2007 or so). Originally, I ran it stably for a ridiculously long time on a WRT54G-L.
Eventually that workhorse died.
I bought a DIR 868L to replace it. Initially I used the stock firmware, but I quickly came to miss the comforts of DD-WRT. By that time, there were some unofficial builds available, so I started experimenting. In a little while, I'd found a build that worked and was only missing features I didn't really care about.
At this time, I noticed that periodically the internet would fail. Wired or WiFi, didn't matter. Changing settings made no difference. Only a factory default reset would fix it. And if I did an NVRAM backup/restore, the issue would re-assert itself.
Every few months, I'd come back and try another build, some wouldn't work at all, but eventually I'd find one that was fairly stable. But this issue continued to re-occur. Sometimes not for a month or more, sometimes 4-5 times a week.
This went on for almost 2 years.
Last week, this happened every single day. After doing some reading, I found that the Netgear R7000 community was growing fairly quickly, so I ordered one on Amazon, to see if this might change my situation.
I followed the install guide, and installed the latest stable from the desipro directory I was sent to (currently r31135M). It ran perfectly fine for a couple days, and then today the internet went down in exactly the same way.
Again, I tried backing up the NVRAM, then factory reseting, restoring. Still down. Messed around with settings, nothing. Factory defaults, and re-configure settings. Fine.
So here I am, two routers over two years, with different builds and different hardware configurations, with the same issue. I can't find anything that seems to directly reference this no-connection scenario, but sorry if I missed it.
D-Link DIR 868L v1 with latest stable Brainslayer build as of some point in September, by memory (don't currently have access to the router). I can provide the webflash upgrade if that will help -- I can't seem to find a way to tell the release number from that.
Netgear R7000 on r31135M configured following the linked guide.
With the R7000, I used the 'erase nvram' method at appropriate steps in the process of initial setup, as indicated.
I have tried re-initializing the R7000, following all the same steps. Same result.
The error specifically is the inability to access the internet through the router. WiFi still works, the LAN still works, I can access the router GUI and SSH in the failure state. It just does not pass through the modem-internet connection (and plugging the modem directly into a computer instantly provides internet, even without power cycling).
It also happens disproportionately at night, usually between 2AM and 8AM PST.
So as best as I can tell, this issue is a Broadcom issue that I haven't been able to find on the forums, or it's a base DD-WRT issue that very few people experience.
And the only other possibility I can imagine is that it's somehow related to my modem, an ARRIS SurfBoard SB6121 (docsis 3.0). It has been the same modem through both routers, but it was also the modem for the WRT-54G-L, and that device never had this issue.
Sorry for the long post. I'm hoping someone can send me in the right direction. Keep in mind, it can take sometimes days or weeks for the no-connection error to occur, so if you need me to do something in that state, it might take some time to update.
Since a factory default restore seems to fix it, and restoring the nvram from before the issue forces the issue to re-occur, I took a backup copy of the NVRAM from the R7000 in both states -- failed connection and functioning. I can provide those, I just wanted to make sure it would be secure to publish those, since they have my configuration information (and WIFI password, etc.) in them.
Joined: 01 Oct 2016 Posts: 172 Location: St.louis, MO USA
Posted: Thu Jan 19, 2017 2:27 Post subject: Re: Two broadcom routers, different builds, same network pro
byeuji wrote:
The error specifically is the inability to access the internet through the router. WiFi still works, the LAN still works, I can access the router GUI and SSH in the failure state. It just does not pass through the modem-internet connection (and plugging the modem directly into a computer instantly provides internet, even without power cycling).
Can you explain this differently? Wifi comes from the router. Lan comes from the router. Your saying there is a signal, but no thoroughput?
I am leaning toward modem ISP. But I dont understand the above. _________________ [MAIN GATEWAY] Netgear R7000 – DD-WRT v3.0-r43324 std (06/02/20)
[AP1-wired] Asus RT-AC68U - D-WRT v3.0-r44467 std (09/24/20)
[AP2-wired] Asus RT-AC68R – D-WRT v3.0-r44467 std (09/24/20)
(switch) 1 AP WRT160N v3 - DD-WRT v3.0-r30731 mini (10/06/16)
==
YOU CAN'T STOP THE COLETRAIN BABY!
I am able to connect to the router and other computers on the LAN via WiFi or LAN, during the failure state. But I cannot access the internet from any devices.
Also, the router can release and renew the lease with the modem, and will display the correct details in the Status page (as though the modem is passing the internet through successfully).
And as I said, if I pull the cable between the router and modem, and plug the router-end into my laptop during a failure-state, my laptop will get internet.
Also the modem is owned by me, so if there's something I can do on there for more info, I can.
Joined: 01 Oct 2016 Posts: 172 Location: St.louis, MO USA
Posted: Thu Jan 19, 2017 3:01 Post subject:
I will confess that my skills and knowledge are low. Maybe someone else has more detailed ideas.
The one oddity is the laptop works. Other than that it sounds like ISP issues. Not really router.
I had an intermittent issue for 6-8 years. Tons of new routers, never solved it. Essentially heat and cold affect the wire. Like tbe main supply wire from the trunk or my box. My biggest issues were in the summer.
I can't believe Its a problem with two differnt routers. Buy a modern, keep the recipt, if it doesn't fix it, return it.
Hope that helps. Good luck. _________________ [MAIN GATEWAY] Netgear R7000 – DD-WRT v3.0-r43324 std (06/02/20)
[AP1-wired] Asus RT-AC68U - D-WRT v3.0-r44467 std (09/24/20)
[AP2-wired] Asus RT-AC68R – D-WRT v3.0-r44467 std (09/24/20)
(switch) 1 AP WRT160N v3 - DD-WRT v3.0-r30731 mini (10/06/16)
==
YOU CAN'T STOP THE COLETRAIN BABY!
Last edited by coletrain on Thu Jan 19, 2017 3:03; edited 1 time in total
Buy a modern, keep the recipt, if it doesn't fix it, return it.
That's pretty much what I intended to do with the router. Hoping I can get this fixed inside the 30 day return policy.
Not ideal that you have to factory reset to resolve the problem.
Did you face the problem when the routers were running the stock firmware? Or did you jump straight to dd-wrt?
I understand that you lose Internet connectivity when the problem happens. I wonder if it somehow relates to DNS on the router and/or an interaction with the modem. With that in mind, should the problem happen again, try accessing a website using the corresponding IP address (of course make a note of the IP address details in advance). Also, the syslog file on the router and/or modem may report some events when the problem happens so it would be good to check those files.
Swapping out the modem sounds like a good move though.
Neither router experiences the issue on their stock firmware. I actually re-flashed the DIR868L prior to buying the R7000 because I needed uninterrupted internet guaranteed for a few weeks. Then I got sick of the stock again and ordered the R7000.
One thing I haven't tried is manually setting the DNS addresses on the router. I have, for sometime, had Google's DNS naturally set on my desktop, but not on the router (this made no difference during the failure state).
Would it make a difference if done in the router instead?
Try this the next time it goes down: Remove power from the modem for 10 seconds then power it up again. Don't do anything to the router.
The SB6121 has also been declared EOL End of Life by Comcast and not supported by them anymore.
Perhaps a newer technology modem is in your future.
I use the SB6190 with my 300mb service. _________________ Segment 1 XR700 10Gb LAN, 1Gb WAN ISP BS
Wired AP 1 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 2 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 3 Unifi Wifi 6 LR US 1Gb LAN
Syslog Services Asustor 7110T NAS 10GB
NetGear XS716T 10GB Switch
download1.dd-wrt.com/dd-wrtv2/downloads/betas/ (Brain Slayer)
YAMon https://usage-monitoring.com/index.php
Not being a network engineer, at first glance, this doesn't seem to be related. From what I read there, I understood it to mean the DSCP was causing slower speeds in general. My issue is 0 internet speeds. LAN connections work (between PCs/devices), but there's no access to the wider internet past the router. Unless the DSCP events cause a disconnect that the router can't recover from, I don't see how they'd be connected.
I'm inclined to try the solution just above this -- to do a power cycle on the modem. I'm surprised the Surfboard I have is EOL already. It's only a couple years old. But it does seem to be the sore thumb in this equation (being the only common device between the seemingly disparate other device configurations/makeups experiencing the issue).
What's frustrating is the infrequency and near randomness this seems to occur on. Because of this, I can't do as some have suggested and "keep the receipt" on a modem. There's a very good chance the problem won't occur for 4+ weeks, and then I'm stuck with another modem :S
Joined: 01 Oct 2016 Posts: 172 Location: St.louis, MO USA
Posted: Fri Jan 20, 2017 2:05 Post subject:
well, if the recipt period expires, ebay.
I have recently become addicted...
I cant believe two totally different routers do the same thing. It cant be that. _________________ [MAIN GATEWAY] Netgear R7000 – DD-WRT v3.0-r43324 std (06/02/20)
[AP1-wired] Asus RT-AC68U - D-WRT v3.0-r44467 std (09/24/20)
[AP2-wired] Asus RT-AC68R – D-WRT v3.0-r44467 std (09/24/20)
(switch) 1 AP WRT160N v3 - DD-WRT v3.0-r30731 mini (10/06/16)
==
YOU CAN'T STOP THE COLETRAIN BABY!
• Access modem via 192.168.100.1 -- failure
• Plug computer direct to modem
• Access modem via 192.168.100.1 -- success
• Record modem log
• Attempt to access internet via modem -- failure
• Reset PC LAN connection
• Attempt to access internet via modem -- failure
• Manually set PC DNS to Google 8.8.8.8 and 8.8.4.4
• Attempt to access internet via modem -- failure
• Manually set PC IP and subnet
• Attempt to access internet via modem -- failure
• Power cycle modem
• Return normal wiring scheme (PC -> Router -> Modem)
• Return PC LAN connection to automatic IP/DNS
• Attempt to access internet via router -- failure
• Record router status
• Attempt to access modem via router -- failure
• Reset PC LAN connection
• Attempt to access internet/modem via router -- failure
• Manually set PC DNS to Google 8.8.8.8 and 8.8.4.4
• Attempt to access internet via modem -- failure
• Manually set PC IP and subnet
• Attempt to access internet/modem via router -- failure
• Return PC LAN connection to automatic IP/DNS
• Attempt to access internet/modem via router -- failure
• Backup NVRAM of Router
• Factory reset router (via DD-WRT web console, "Restore Factory Defaults" )
• Attempt to access internet/modem via router -- success
• Re-configure router for customary settings
• Backup NVRAM of Router
Feb 01 2017 11:23:54 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:00;CM-QOS=1.1;CM-VER=3.0;
Jan 21 2017 01:20:40 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 18 2017 03:30:44 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:02:54 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:02:13 5-Warning R09.0 B-INIT-RNG Failure - Retries exceeded;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:02:11 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:01:13 5-Warning R09.0 B-INIT-RNG Failure - Retries exceeded;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:01:12 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:23;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14 6-Notice N/A Cable Modem Reboot due to T4 timeout ;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:00;CM-QOS=1.1;CM-VER=3.0;
Jan 18 2017 03:27:03 3-Critical R04.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Jan 18 2017 03:24:57 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Jan 15 2017 20:11:14 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:00;CM-QOS=1.1;CM-VER=3.0;
Jan 11 2017 20:25:39 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:13 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx:00;CM-QOS=1.1;CM-VER=3.0;
Jan 11 2017 15:58:26 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Jan 04 2017 06:45:41 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Dec 30 2016 14:26:24 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Dec 09 2016 21:23:20 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=xx:xx:xx:xx:xx:e1;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.0;
Attached also are the status panes of various places in the DD-WRT web interface, as well as a screenshot of the state of my router (SNR, Power Level, etc.)
With this result, I can only conclude that there is either something that the modem is doing that the router cannot handle, or there is a software defect in the build (and multiple builds for multiple types of hardware, because this result is identical to the results I got when troubleshooting my DIR 868L).
I'd be happy to email/PM anyone the NVRAM dumps I took before and after factory resetting the router, if it'll help -- though I'd like to know if that's going to share anything like my wifi password, etc. before I do :x
The only thing out of the ordinary I noticed was that the modem log indicated a power reset around what looks to be 11AM this morning. I know the internet was working when I left the house this morning, and failed by 4PM this afternoon. I'm not sure why a power reset would cause this issue though, when me resetting the power manually doesn't seem to have an effect.
Are there any scenarios in which the SB6121 would post a power reset reboot but *not* do a complete power cycle?
I like the R7000, so I've decided to keep it regardless -- WiFi in the house has been much stronger, but I'd like to put this info out there one last time before I blow another $100 on a new modem to try to fix this.
Any thoughts?
[I seem to be limited to 3 images, so here's the fourth one hosted elsewhere:]
If the modem itself issues a reboot in response to a critical error
it retains the mac addresses it has learned from what device(s) that have connected to it's ethernet port.
If power is removed from the modem then the learned addresses are lost and it re-learns the mac of what is connected to it.
Your ISP determines how many macs are allowed to connect to it. It may be one (normally that of a router) or it could be up to 5. My ISP allows 4, 3 routers on a vlan plus the mac of the smartswitch connected to the modem.
Any macs present above the preset limit are ignored and not granted a connection.
If your modem is configured for one connection when you unplug the router and plug your pc in it's not going to get an internet connection until you remove power from the modem to remove the learned mac. _________________ Segment 1 XR700 10Gb LAN, 1Gb WAN ISP BS
Wired AP 1 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 2 Unifi Wifi 6 LR US 1Gb LAN
Wired AP 3 Unifi Wifi 6 LR US 1Gb LAN
Syslog Services Asustor 7110T NAS 10GB
NetGear XS716T 10GB Switch
download1.dd-wrt.com/dd-wrtv2/downloads/betas/ (Brain Slayer)
YAMon https://usage-monitoring.com/index.php
Last edited by ddaniel51 on Thu Feb 02, 2017 4:07; edited 1 time in total
Really informative response, thank you. I don't know much about modem hardware and the interaction with the ISP.
In that case, what is the best solution? Is the modem's critical error fixable through some configuration, or is it likely a hardware error?
More importantly, if I were to replace the modem, what's the likelihood this issue would recur?
Edit: Also, given your explanation, why didn't power cycling the modem restore connection to the router until I did a factory default reset on the router?
It actually looks like we had a power surge or power outage today at 11:23. My PC Event Log has a recorded unexpected shutdown at exactly the same time as the modem.
Which honestly should have acted like a power cycle for the modem anyway. Unless the power outage affected the local network node too, I'm not sure why the modem wouldn't treat that like a manual power cycle.
