C7000-100NAS randomly drops internet connection

I don't know if I need to be notified when the class action happens. I am comfortable to know that I will never purchase another Netgear product EVER. I have save all of my many devices over the years for some dumb reason. But, I threw this Netgear device and all previous devices in the trash. I have replace this setup with ASUS and it works great. Since then, I have bought other equipment like wireless extenders. Even though Netgear claims to have good stuff in these areas, I did not buy theirs and NEVER EVER will again EVER>

Garybaird,

what is your recommended asus setup (models)?  Are you with Spectrum?

I fought with Netgear for the past 3 months with issues with my C6300 dropping wifi.  After swapping my modem twice, they decided to "upgrade" me to the c7000. Now I have THIS problem. I don't have the patience to go through another saga with their Gearhead (blockhead!) support even though I still have a few months left on my extorted "contract". 

Crazyrat - don't buy Netgear 

We have Comcast and UPnP is off on the NetGear Not sure why, but when we get a

[DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53

75.75.75.75 is Comcast's DNS Server

Our connection is non usable.  We also have Magic Jack and when calls are coming in, we answer and loose incoming audio for about 5 to 15 seconds. 

When this happens, I check the logs and it shows this [DoS attack: TCP- or UDP-based Port Scan] from 75.75.75.75, port 53 in the logs. 

Comcast inside guy says that his meter shows Frequency 603 Errors, while the lineman says that is not what his meter shows.  We now have a monitoring device on our pole until Friday.

I am at a loss at this time.  Does port 53 have to be open to incomming traffic or can I shut it off some how on this modem.  I could do that on my zoom.

During the issues below, our use of the internet is dead.

All ideas and suggestions are welcome.  There is something causing all of this.

Do any senior techs actually monitor these posts?  If this kind of customer feed back happened in my business, I would be out of business.

Suggestions welcome.

Try using OpenDNS for reliable access to the internet and protect against attack.  This is a free service ("Home" version of Cisco's OpenDNS).

You can review this option at "www.opendns.net".  The service directs internet connections to through safe links.  A simple change to either the computer's or router's domain server addresses.  It may help with stopping the DoS attacks (unless they are coming through IPv6).

Some anti-virus, etc., programs will shut-off internet service if the computer is under attack.  The external attack may also attempt to corrupt the router settings.  The OpenDNS domain settings (and service) are designed to prevent such incoming attacks.

NetGear's "parental settings" (via OpenDNS) allow the user to block access to selected internet sites (most which tend to cause DoS, and other nasties).

The OpenDNS service will not correct hardware issues that may related to NetGear's router malfunctions.

Have you checked the "Port Scan and DoS Protection" settings on the router?

See: "http://kb.netgear.com/19957/What-does-Disable-Port-Scan-and-DoS-Protection-do?cid=wmt_netgear_organic".

I had some problems and found a reference to "disable" this setting - and afterwards the problems ceased.

You can check your system's response with the setting enabled and disabled to see if that makes a difference.

Using OpenDNS to name the server domains will also help.  See: "www.OpenDNS.net" for details.

Do not disable any firewall or anti virus protection on your computer. 

Thanks for the response,but Disable Port Scan and DoS Protection is not checksed so it is supposed to be on and Respond to Ping on Internet Port is also unchecked, so it doesn't respond to a ping.

Just so you know, the url is opendns.com and opendns is now a part of Cisco.

The comcast line staff have been out and set up monitoring of my line.  I had two significant drops thus far.  They are now monitoring every box from our pole  back to the main switch.

I propose to them that I change my DNS location and see if that helps.  They thought it a good idea.  Don't understand why the Comcast DNS server would DoS Attack my IP.  

Is anyone else on Comcast having the same issue in the Chicago area for 75.75.75.75  or 75.75.76.76?

I think I may have found a solution...at least for me. 

I purchased one of these C7000-100NAS  units and swapped it back for another one. I too had Comcast say that they could find NOTHING wrong. 

I put the router into bridge mode, and called Comcast one last time. They wanted me to put the unit back into router mode; in an effort to be expeditious, I performed a hardware reset to get it back into router mode.  

Note that this reset is not just a disconnect from power and restart, it is a full hardware reset where the reset button is pressed and held for 7 seconds ( I held for 20). 

That did the trick! 

I did not see anyone in this thread mention a hardware reset as described above.  Many think a disconnect from power is a reset.I have reset it three times and it works like a champ.  No delay...performance is fantastic. Been running for a couple of weeks!

This may not resolve everyone else's issue but it sure resolved it for me. 

When this unit works, it screams. 

Good luck to everyone.