Netgear C6900 issues

I have a netgear c6900 modem, router ... every 2 -3 hours my internet connection drops. ...

Perhaps not the root of the problem, but you should be aware that the C6900 is no longer an approved device. See https://www.xfinity.com/support/devices.

Using devices on speed tiers for which they are not approved, and using devices that are no longer approved, tends to produce unexpected results, often speeds well below the manufacturer's rating. It would be best to pick one of the modems on the "Devices" page that is approved for the your Internet speed tier or, to allow for Comcast's periodic speed increases, perhaps a step or two higher.

If you want to troubleshoot the C6900, please see Internet Troubleshooting Tips. If you still need help, please post your Internet plan speed and the following information from your gateway (from http://192.168.100.1):

• downstream: power levels, SNR (or MER), error counts, and uptime
  
• upstream: power levels
• event log, if available (Be sure to remove or blot out any MAC addresses. Forum security processing considers them "personal information" and may prevent the event log from posting if these are present.)

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The concern is not "Xfinity Home Security / Devices And Equipment" help related............ Topic moved here to the proper help section for assistance. 

... I have a up to 400mbps plan ... Here's my logs ...

The signal stats posted were good at the time they were taken. The log entries are not helpful as they appear to be for router events, rather than modem events.

Are you connecting via Wifi or Ethernet? If Wifi, it's best to switch to an Ethernet cable connection if possible for testing. That would allow you to determine whether the problem is the Wifi signal or the link between your modem or gateway and Comcast's network. Network connection problems that affect both Ethernet and Wifi devices are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power. 

As I see it the most likely possibilities are 1) an intermittent network connection, 2) an intermittent noise source, 3) a problem upstream toward Comcast.

If you can't find the problem or you'd rather have Comcast take care of it and an employee does not respond to your message here, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.

If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit ($70-$100) unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.