Nighthawk R6700v2 losing connection to CM700 Modem

[Thompa3642]

Hi there,

We are relatively new Comcast Xfinity custmers and decided to buy our own Modem (CM700) and Router (Nighthawk R6700v2).

Every morning we find that our computers are disconnected from the internet (DNS Server error), although the Comcast Home Security system is connected through our Modem... and I can access the Internet on my phone when the computers show they are disconnected, however.

Each morning, I have manually reset the modem. Today, however, I reset the router instead and the system came back up... which suggests the problem is with the router.

I have been told Comcast send updates around midnight every day... and thought this might be causing the modem/routers issues...

Can anyone advise on how I would investigate the issue with the router?

Thanks in anticipation,

Allan

[Thompa3642 · Accepted solution]

Hi there,

Wanted to update this thread....

Since I downloaded and installed the latest firmware for the R6700 to V1.2.0.12_1.0.1, 4 days ago, my disconnection issues in the mornings has evaporated!

I know it is early days... but the update seems to have worked!

Thank you for doing this!

Made our lives much easier!

Regards,

Allan Thompson

[mbradley3]

I am having the same issues.  The only difference is that we have a motorola surfboard modem.  Would love some help too.

[JamesGL]

Hi All,

If the router has no connection, bypass the router and check if the modem has internet without rebooting it.

[JamesGL]

Hi All,

We’d greatly appreciate hearing your feedback letting us know if you need further assistance.

[Thompa3642]

Hi there,

Thanks for replying - we are away from home at the moment..

Yes, bypassing the router and using just the modem, gives us access to the internet

 Hoping this helps!

regards,

Allan

[JamesGL]

Hi Thompa3642,

May I know what is the firmware version of the router? Make sure it is updated. (https://kb.netgear.com/000038706/R6700v2-Firmware-Version-1-1-0-34)

[Thompa3642]

Hi there,

Yes - updated to the latest firmware.

Allan

[JamesGL]

Hi Thompa3642,

Please check your inbox.

[TheWorstPing]

which surfboard are you using?

[Thompa3642]

Sorry - don't understand - what do you mean by 'surfboard'?

[TheWorstPing]

which modem..

[Thompa3642]

There is a Netgear CM700 modem and Comcast supplied a Netgear modem for their security system.

[eligia]

Sub'd for updates. 

[Thompa3642]

Hi Again,

Sadly after being away for a few months we returned home to our home and found we are still experiencing the same issues... each morning I have to reset the system to reconnect to the internet..

I immediately checked to see whether there were any firmware updates... to make sure I was running the latest.

I have investigated and am bemused by what I found...

Some wireless and wired devices are disconnected from the imrenet... but some remain connected.

My phone remains connected and I can happily browse the internet, read emails etc. but my wife's Chromebook is disconnected.

I rebooted the modem (CM700) and this had no effect on the connected devices.

Had to reboot the R6700v2 and this reconnected us to the Internet.

Checking the log on the R6700v2:

[DoS attack: ACK Scan] from source: 31.13.67.11:443 Sunday, December 10,2017 11:12:53        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:12:38   (Thermostat)  
[DoS attack: ACK Scan] from source: 192.241.185.248:443 Sunday, December 10,2017 11:12:25        
[DoS attack: ACK Scan] from source: 104.154.164.197:443 Sunday, December 10,2017 11:12:05        
[admin login] from source 192.168.1.10 Sunday, December 10,2017 11:11:50        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:11:38        (Thermostat)
[DoS attack: ACK Scan] from source: 52.39.177.168:443 Sunday, December 10,2017 11:11:09        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:10:37        (Thermostat)
[DoS attack: ACK Scan] from source: 192.241.185.248:443 Sunday, December 10,2017 11:10:25        
[DoS attack: ACK Scan] from source: 104.154.164.197:443 Sunday, December 10,2017 11:10:04        
[DoS attack: ACK Scan] from source: 34.228.163.174:443 Sunday, December 10,2017 11:09:43        
[UPnP set event:AddPortMapping] from source 192.168.1.36 Sunday, December 10,2017 11:09:39        
[DHCP IP: (192.168.1.4)] to MAC address 48:D2:24:1F:B8:49 Sunday, December 10,2017 11:09:38        (Windows laptop)
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:09:36        (Thermostat)
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:09:29        
[DoS attack: ACK Scan] from source: 52.39.177.168:443 Sunday, December 10,2017 11:09:08        
[DoS attack: ACK Scan] from source: 74.125.139.188:5228 Sunday, December 10,2017 11:08:46        
[DHCP IP: (192.168.1.21)] to MAC address E0:46:9A:44:42:31 Sunday, December 10,2017 11:08:34        (xfinity Security modem)
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:08:34        (Thermostat)
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:08:21        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:07:34        (Thermostat)
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:07:21        
[DoS attack: ACK Scan] from source: 13.115.29.218:5223 Sunday, December 10,2017 11:07:01        
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:06:40        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:06:33        (Thermostat)
[DoS attack: ACK Scan] from source: 65.52.108.219:443 Sunday, December 10,2017 11:06:18        
[DHCP IP: (192.168.1.19)] to MAC address F4:B7:E2:28:BC:11 Sunday, December 10,2017 11:05:59        (Printer)
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:05:57        
[DHCP IP: (192.168.1.18)] to MAC address 02:0F:B5:07:37:40 Sunday, December 10,2017 11:05:49        
[DHCP IP: (192.168.1.17)] to MAC address D0:76:58:07:A4:66 Sunday, December 10,2017 11:05:45        
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:05:37        
[UPnP set event:AddPortMapping] from source 192.168.1.4 Sunday, December 10,2017 11:05:37        
[DoS attack: ACK Scan] from source: 62.254.26.207:993 Sunday, December 10,2017 11:05:34        
[UPnP set event:AddPortMapping] from source 192.168.1.10 Sunday, December 10,2017 11:05:33        
[DoS attack: ACK Scan] from source: 54.198.88.45:3478 Sunday, December 10,2017 11:05:32        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:05:32        (Thermostat)
[DHCP IP: (192.168.1.11)] to MAC address 00:1F:1F:22:8C:B4 Sunday, December 10,2017 11:05:28        
[DHCP IP: (192.168.1.16)] to MAC address 2C:3A:E8:26:89:86 Sunday, December 10,2017 11:05:15        
[DoS attack: ACK Scan] from source: 65.52.108.212:443 Sunday, December 10,2017 11:05:10        
[DHCP IP: (192.168.1.19)] to MAC address F4:B7:E2:28:BC:11 Sunday, December 10,2017 11:04:58        
[DHCP IP: (192.168.1.7)] to MAC address 6C:33:A9:2E:B8:71 Sunday, December 10,2017 11:04:56        
[DHCP IP: (192.168.1.7)] to MAC address 6C:33:A9:2E:B8:71 Sunday, December 10,2017 11:04:56        
[DHCP IP: (192.168.1.7)] to MAC address 6C:33:A9:2E:B8:71 Sunday, December 10,2017 11:04:56        
[DHCP IP: (192.168.1.7)] to MAC address 6C:33:A9:2E:B8:71 Sunday, December 10,2017 11:04:56        
[DHCP IP: (192.168.1.7)] to MAC address 6C:33:A9:2E:B8:71 Sunday, December 10,2017 11:04:56        
[DoS attack: ACK Scan] from source: 172.217.8.78:443 Sunday, December 10,2017 11:04:50        
[admin login] from source 192.168.1.10 Sunday, December 10,2017 11:04:44        
[UPnP set event:AddPortMapping] from source 192.168.1.9 Sunday, December 10,2017 11:04:39        
[DoS attack: ACK Scan] from source: 65.52.108.226:443 Sunday, December 10,2017 11:04:38        
[UPnP set event:AddPortMapping] from source 192.168.1.8 Sunday, December 10,2017 11:04:37        
[UPnP set event:AddPortMapping] from source 192.168.1.8 Sunday, December 10,2017 11:04:37        
[UPnP set event:AddPortMapping] from source 192.168.1.8 Sunday, December 10,2017 11:04:37        
[UPnP set event:AddPortMapping] from source 192.168.1.8 Sunday, December 10,2017 11:04:37        
[UPnP set event:AddPortMapping] from source 192.168.1.8 Sunday, December 10,2017 11:04:37        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:04:32        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:04:32        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:04:32        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:04:32        
[DHCP IP: (192.168.1.15)] to MAC address 44:61:32:08:40:37 Sunday, December 10,2017 11:04:32        
[DoS attack: ACK Scan] from source: 62.254.26.223:993 Sunday, December 10,2017 11:04:29        
[DHCP IP: (192.168.1.14)] to MAC address D0:E7:82:D6:0E:21 Sunday, December 10,2017 11:04:18        
[DHCP IP: (192.168.1.12)] to MAC address EC:1A:59:EB:9F:D5 Sunday, December 10,2017 11:04:17        
[DHCP IP: (192.168.1.6)] to MAC address 02:0F:B5:02:AF:57 Sunday, December 10,2017 11:04:15        
[DHCP IP: (192.168.1.11)] to MAC address 00:1F:1F:22:8C:B4 Sunday, December 10,2017 11:04:14        
[Time synchronized with NTP server time-a.netgear.com] Sunday, December 10,2017 11:04:13        
[DHCP IP: (192.168.1.9)] to MAC address 02:0F:B5:AA:9F:FC Sunday, December 10,2017 11:04:12        
[DoS attack: ACK Scan] from source: 192.241.185.248:443 Sunday, December 10,2017 11:04:09        
[DHCP IP: (192.168.1.11)] to MAC address 00:1F:1F:22:8C:B4 Sunday, December 10,2017 11:04:09        
[DHCP IP: (192.168.1.4)] to MAC address 48:D2:24:1F:B8:49 Sunday, December 10,2017 11:04:08        
[DHCP IP: (192.168.1.5)] to MAC address 70:4F:57:B8:D2:49 Sunday, December 10,2017 11:04:06        
[Internet connected] IP address: 73.55.27.178 Sunday, December 10,2017 11:04:06        
[DHCP IP: (192.168.1.2)] to MAC address 10:A5:D0:85:37:F3 Sunday, December 10,2017 11:04:06        
[DHCP IP: (192.168.1.20)] to MAC address A4:C4:94:79:4D:2A Sunday, December 10,2017 11:04:06        
[DHCP IP: (192.168.1.5)] to MAC address 70:4F:57:B8:D2:49 Sunday, December 10,2017 11:04:06        
[DHCP IP: (192.168.1.3)] to MAC address 00:23:A7:2B:B8:28 Sunday, December 10,2017 11:04:04       

Can all of the reported DoS attacks be correct?

Here's a grab from the CM700 just now... after I had another disconnection!

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 753000000 Hz Locked Connectivity State Ok Operational Boot State Ok Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables UnCorrectables 1 Locked QAM 256 1 591000000 Hz 3.7 dBmV 38.9 dB 461 2912 2 Locked QAM 256 2 597000000 Hz 3.9 dBmV 38.9 dB 511 2704 3 Locked QAM 256 3 603000000 Hz 4.0 dBmV 38.9 dB 1081 2810 4 Locked QAM 256 4 609000000 Hz 4.0 dBmV 38.9 dB 386 1757 5 Locked QAM 256 5 615000000 Hz 4.0 dBmV 38.6 dB 925 2197 6 Locked QAM 256 6 621000000 Hz 4.0 dBmV 38.6 dB 606 1639 7 Locked QAM 256 7 627000000 Hz 4.0 dBmV 38.9 dB 320 1527 8 Locked QAM 256 8 633000000 Hz 3.7 dBmV 38.9 dB 502 2461 9 Locked QAM 256 9 639000000 Hz 3.7 dBmV 38.9 dB 490 2528 10 Locked QAM 256 10 645000000 Hz 3.7 dBmV 38.9 dB 698 1281 11 Locked QAM 256 11 651000000 Hz 3.5 dBmV 38.9 dB 573 1390 12 Locked QAM 256 12 657000000 Hz 3.4 dBmV 38.9 dB 412 2753 13 Locked QAM 256 13 663000000 Hz 3.5 dBmV 38.6 dB 616 1484 14 Locked QAM 256 14 669000000 Hz 3.5 dBmV 38.6 dB 478 1741 15 Locked QAM 256 15 675000000 Hz 3.4 dBmV 38.9 dB 435 1838 16 Locked QAM 256 16 681000000 Hz 3.2 dBmV 38.6 dB 310 1565 17 Locked QAM 256 17 687000000 Hz 3.0 dBmV 38.9 dB 629 2650 18 Locked QAM 256 18 693000000 Hz 3.0 dBmV 38.9 dB 568 1466 19 Locked QAM 256 19 699000000 Hz 3.0 dBmV 38.6 dB 675 1348 20 Locked QAM 256 20 705000000 Hz 2.9 dBmV 38.6 dB 504 2576 21 Locked QAM 256 21 711000000 Hz 2.7 dBmV 38.6 dB 463 2857 22 Locked QAM 256 22 717000000 Hz 2.2 dBmV 37.6 dB 681 2395 23 Locked QAM 256 23 723000000 Hz 1.7 dBmV 38.6 dB 821 2442 24 Locked QAM 256 24 729000000 Hz 0.9 dBmV 37.9 dB 153 705 25 Locked QAM 256 25 735000000 Hz 0.2 dBmV 37.6 dB 276 671 26 Locked QAM 256 26 741000000 Hz -0.2 dBmV 37.3 dB 303 732 27 Locked QAM 256 27 747000000 Hz -1.0 dBmV 36.9 dB 351 845 28 Locked QAM 256 28 753000000 Hz -1.7 dBmV 36.6 dB 794 4698 29 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0 30 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0 31 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0 32 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 4 5120 Ksym/sec 16600000 Hz 43.0 dBmV 2 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 42.3 dBmV 3 Locked ATDMA 2 5120 Ksym/sec 29400000 Hz 41.5 dBmV 4 Locked ATDMA 1 5120 Ksym/sec 35800000 Hz 41.0 dBmV 5 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV

Hope someone can help us!

Regards,

Allan

[Thompa3642]

Interesting thsi morning.... using my phone on the internet while my wife could not get an internet connection.... she was not happy... but that isn't the point!

When I checked my phone wif connection. I was connected to the 5G signal and she was not. I changed my phone's wifi to connect to the 2.4Ghz signal and immediately was told there was no internet connection. Weird!

Does this help anyone analyse why I still have to reset the R6700v2 every morning?

Very desparate for a solution now... will be nuying another router in the January sales!

[Thompa3642 · Accepted solution]

Hi there,

Wanted to update this thread....

Since I downloaded and installed the latest firmware for the R6700 to V1.2.0.12_1.0.1, 4 days ago, my disconnection issues in the mornings has evaporated!

I know it is early days... but the update seems to have worked!

Thank you for doing this!

Made our lives much easier!

Regards,

Allan Thompson