R7960P - Router failing or?

[CKopp]

Unusual Problem just cropped up.  The router fails to work periodically.  When that happens lights all seem to work (lit or flashing periodically) except you can't connect to the router.  Interestingly when I do an IPCONFIG on one of my computers I notice that the IP address on that computer is gone, which is not what I expected because I would think it would take time for the lease to expire.  I set up a computer with a manual IP, and that one could not connect either.  Each time I turn off the router and then back on, it resolves itself.  

Perhaps coincidently, this all started a few days after I turned IPV6 on.  I did that to resolve the DNS issues that existed with the last firmware update .88.  

The last time the router came back up, I noticed that w it was set to 6to4 tunnel. I was pretty sure I used autoconfig, so this surprised me but maybe the ISP DCHPv6 was not working when I configured it.  I then tried auto config and it then set the router to DHCP.

It works again now, and I am waiting to see if the failure happens. (It was happening once every 1-2 days, but last time the failure interval was 12 hours after the last reset.  If it does I was planning to try turning IPV6 off and going back to resolving DNS on individual machines to see if that makes any difference.

Anyone else see anything like this?  Any other thoughts?

[FURRYe38]

What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?
Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 

Has a power off for 1 minute then back ON with the ISP modem and router been performed since last update?
Be sure to restart your network in this sequence:
Turn off and unplug modem.
Turn off router and computers.
Plug in and turn on modem. Wait 2 minutes for it to connect.
Turn on the router and wait 2 minutes for it to connect.
Turn on computers and rest of network.

Has a factory reset and setup from scratch been performed since last FW update?

Try setting a default DHCP IP address range of .100 to .200 instead of the larger pool size. 

Does the router feel extra warm or hot when this happens? I keep a laptop cooler fan under my router  for  24/7  cooling. 

[CKopp]

The modem is hard to get to, it is a ISP Charter supplied modem (Spectrum make Docsis 3.1 rating).

Cable is either Cat  6 or Cat6/E. Top of the line patch from mono price.

Yes I performed such a cycle before the last 12 hours between failure. But the majority of time I just have been shutting of the router, waiting 30 sec and turning it back on.

No I have not done a factory reset from scratch.  I will consider trying such a move, but keep in mind the last firm ware upgrade was several months  ago, and this problem only showed up a couple weeks ago.

I am trying one change at a time, want to see how this IPV6 change (from 6to4  to DHCP) impacts things.  If still happening, I will first try turning  IPV6 off. Then I'll try a reset.

My DHCP pool is already restricted .002 to .037.

Does turning on IPV6 stress the router more (especially the 6to4 tunnel setting)?

No the router is warm but not at all hot.  I also blew it out with compressed air to make sure no dust impeding cooling transfer.

So far, after the change to DHCP on the IPV6, it has not crashed yet and I have hit the 12 hour mark (fingers crossed)

[FURRYe38]

Auto should be used for IPv6. I think 6to4 is being depreciated. 

Let us know how it turns out. 

[CKopp]

Yes, I am not sure how 6to4 tunneling was originally set, I thought when I turned on IPV6, I specified Auto Detect.  But 6to4 is next option in list so maybe I overshot.  

So far its been stable for 24 hrs but I am monitoring.  Do you know how routing works with IPV6 and IPV4 turned on simultaneously?  IS there an attempt to route via IPV6 first with the IPV4 attempt a fallback?

[FURRYe38]

I believe routing tries with IPv4 first, then IPv6, even if your ISP doesn't support native IPv6 services, seems like the router checks the IPv6 path when enabled. 

There is a known problem in the IPv4 DNS stack across all R series routers that causes a delay in DNS handling. Thus users see a DNS error message in browsers here and there. Some browsers can continue past this while others don't. Some one just happen to stumble across enabled IPv6 (Auto) and seems to be a work around. We've let NG know about this. 

[CKopp]

Yes, I am familiar with the DNS stack timing problem which showed up with the newest firmware release.  I saw it on any chrome based browser (Chrome, Edge).

Interestingly enough, I notice that choosing the auto config option seems to result in another one of the options on the list being ultimately selected after a routine executes (most recently in my case, DHCP). Out of curiosity, when others have run the autoconfig option, what has been the result for them, DHCP?  or a range of options dependent on ISP? 

[FURRYe38]

Please post a screen capture of what you see when IPv6 Auto is enabled for you.

[CKopp]

I just realized that I was selecting the AUTO Detect option, not autoconfig 🙄.  Selecting auto config results in the same options, except:

1. The option settings remains on Autoconfig instead of switching to DHCP.

2. The router IPv6 address on WAN switches from an actual address to "address unavailable". 

Any reason I don't want the DHCP option that autodetect came up with?  Otherwise I'll test with this before trying auto config as my next choice (before heading towards turning IPv6 off)

[FURRYe38]

Auto detect will just check to see if there is an IPv6 address from the ISP services, if they support it, then the router will get that IP address from the ISP, if not, then address unavailable will appear. 

[CKopp]

Why does the auto config option not try for am IPv6 address as well?

[FURRYe38]

May rely on some user config. Not sure...or possible that the IPv6 is broke here. We are seeing problems on Orbi systems were IPv6 is broke and not working right. 🙄

[CKopp]

Ok, so it crashed again.  However this time when I restarted I noticed an IP conflict on the LAN side. Could that cause my crashes?  I fixed that via address reservation and am trying again DHCP.  This time it dropped in the middle of a zoom conference call.  Up to now, crashes have been at night, late.  I have a backup  - New R6700 that I might need to switch to. 

[FURRYe38]

Ya I would find out what the IP conflicts are and help avoid them. Reboot all of your devices. I'd start turn OFF everything and then turn them On again one by one. Make reservations as you go for the items you want to have a reserved IP address for. 

[CKopp]

Ok, so Auto detect did not work.  Crashed in approximately 20 hours from last crash.   Next trying auto config.  If not that, then I will try shutting IPv6 off.  Luckily, I have backup R6700  updated to current Firmware and ready to drop in place.

[FURRYe38]

👍

[FURRYe38]

Might try reverting FW as well. Others are reporting using v.68. 

[CKopp]

That lasted about 36 hours.  Going to go back to turning IPv6 off and using local DNS to see if that resolves things.  Not to thrilled to go back to ver .68, that means accepting the security risk it mitigates.  Do we have any word on when Netgear will deliver a FW update that both addresses the security issues, and in which DNS is not broken for IPv4?  This is getting frustrating, and it appears a lot of Netgear routers have problems with the current FW.

[FURRYe38]

We keep asking and pushing on this. Ya it's across the board for R series routers for DNS issues. Possible IPv6 maybe broke as well since the IPv6 package could be out of date.  No idea if or when NG will fix em. Trust me, we understand the frustrations. 🙄

[CKopp]

I just updated to the firmware that just came out (.94).  First time in several updates where it went smooth, updated from browser page, router downloaded and updated, rebooted and came right back up.

First the good news.  I tested for about 50 rapid fire web loads off my favorites list .  Every single one loaded lickety split.  NO DNS probe errors!  This may be the fix we have been waiting for!!!! (under previous FW, the farthest I could get was 25, and loading was often delayed)

Regarding my recent issues with crashes:  I have now disabled IPv6 as it doesn't seem that it is necessary for proper DNS resolution and will monitor.

[FURRYe38]

Kewl. Seems that just arrived. I'll get it posted. 

Keep us posted on how it goes. If IPv6 is disabled and using normal DNS, hoping NG finally fixed the DNS issue. 

[CKopp]

Well, it has now been a few hours. 

AN observation:   1. DNS does not appear to be fully fixed.  It is noticeably better in that the DNS probe message does not pop up as often, and when it does, resolves itself after a couple seconds, vs. before when it would require one or more reloads.

I will try re-enabling IPv6 to see if that fixes the problem without crashing under new FW.  Stay tuned.

[FURRYe38]

Ok. I just put mine online and and IPv6 is disabled. 

I haven't seen anything so far but will give it a few days to see what I find. 

You might fully clear out the PC DNS and ALL Browser caches before re-enableing IPv6. Be sure it's all clear then start testing over.

[CKopp]

Ok, enabling IPv6 did not help much.  I get about 30hrs between crashes.  So I ma trying the last part.  Running with IPv6 disabled again.

[FURRYe38]

Are you streaming or is the router under heavy load when the crash happens? 

Wondering if there is something else going on with your Router. Doesn't seem like this is a FW issue. Thought I did a factory reset and setup from scratch yesterday since I fiddled with IPv6 and it was enabled by accident, Mines been online since the day the new FW appeared and has been online solid. No DNS issues seen so far. 32 Devices connected.

Possible there is something causing the router to crash or the router maybe faulty. 

I keep a fan under my router for additional cooling.