Orbi RBR-50 dropping internet connection to modem intermittently

[mahart1975]

Figured I'd post my positive results here on a thorny issue with my Orbi system.  I have an RBR-50 with an RBR-30 satellite and one of the wall plugin satellites.  So about 3 weeks ago or so, I updated my firmware to 2.7.2.104 and then about one week ago, my internet wasn't working on any of my devices.  

So I did some troubleshooting... started with my Xfinity cable modem and was able to plug in my laptop hardwired to it and the internet was active and working fine.  I did some diagnostics with their support to make sure the modem was clear and it was.

So that pointed to my Orbi router having a problem.  When internet was down, I logged into my Orbi iPhone app and it reported Internet: Offline but all the devices were still connected to the system over Wifi.  

The only way to resolve this was to reboot the Orbi main router and 2 mins later the internet was fine again, but this situation would happen multiple times a day intermittently.  VERY disruptive and I use my internet for work.

Ok... so none of the Netgear Community suggestions did anything to fix this.  It was just "uncheck this feature", "change your lease settings with this command line", "turn off circle or armour and uncheck this."  Nothing that made ANY sense.

I ended up paying for the Netgear support for $89 for 6 months.  The first support agent I got could barely speak English, nearly incomprehensible but his suggestions also I knew immediatley would not fix the problem.  He changed an MTU buffer size (sigh) and the frequency on the antenna, dumb stuff like that that I knew were a waste of time.  

I called back in and got a more senior engineer on the phone and he was very good.  He did a remote session with me and went right to the logs (what I suggested to the first engineer) and figured out the problem... 

So the Netgear Orbi system has Denial of Service (DoS) protection as a feature and this was turned on.  What was happening was, my Gmail and iCloud streams were flooding the router with requests all at once (this is normal) and the router's response is to disconnect the internet to stop what it thinks is a DoS attack.  And the only way to turn internet back on according to the support engineer is to reboot it.  

So we ended up disabling the DoS protection feature as you either have it on or off and can't really change its behavior of killing internet to "protect" you.  That fixed the problem for me.  

You can find that setting under the ADVANCED tab and then Setup>WAN Setup... CHECK "Disable Port Scan & DoS Protection" and apply the changes.

There are better ways to protect your home network from DoS and hackers than to use these features but that's for another post.

[tucsontico]

Thanks for your troubleshooting input. Seems pretty odd to me that a firmware update specifically designed to address "Security Vulnerabilities" (v2.7.2.104) would require the user to turn off a DoS attack prevention mode. However, if your set up is working well, then this may be the answer for the group of folks struggling with loss of internet due to the v2.7.2.104 firmware. 

[vajim]

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@tucsontico wrote:

Thanks for your troubleshooting input. Seems pretty odd to me that a firmware update specifically designed to address "Security Vulnerabilities" (v2.7.2.104) would require the user to turn off a DoS attack prevention mode. However, if your set up is working well, then this may be the answer for the group of folks struggling with loss of internet due to the v2.7.2.104 firmware. 

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If you look at the release notes on most of the recent firmware versions, most mention "Security Vulnerabilities"....almost like they use that as a way to get most folks to believe its important...??

[mahart1975]

I actually didn't look at the release notes to see if this DoS feature was added with this new firmware I installed.  I installed it because I was trying to resolve a different problem... in the newer version I read that they added enhancements to how devices would connect to the nearest Orbi node (router or satellite) and I was on some very old firmware.  

This behavior of the internet dropping started to occur shortly after the firmware upgrade and that was the ONLY thing that changed in my environment so I figured it must be connected.

The DoS protection they have apparently is just ON or OFF and you can't set any thresholds on when it decides to turn internet off to protect you.  I.e. X amount of data in X number of seconds, deactive internet.  Nope, it just has some internally set threshold of data that flows in that it then deems a DoS even though it was legit traffic.  So yep, just had to turn that feature off or keep facing internet drops.