Modem Reboots Frequently

There are many typical reasons this could be happening:

1) IPv6 bug, (scratched because you've turned that off),

2) Bad Gateway, (scatched because you've had it replaced twice),

3) Overheating due to poor air circulation,

4) Power issues (brownouts, RF on the power line)

5) Line quality issues

6) RFI inducing noise on the line

Switching to the 5268ac may help with 5 & 6.  It likely will not help with 3 & 4.

Have you checked the stats table on the Broadband page to see what your line quality is like and what kind of error counts you're getting?  You can take a screenshot of that informational table and paste it here for our analysis.

Is the Gateway plugged directly into the wall (i.e. not through a powerstrip or UPS)?  If not, can you try that (because a bad powerstrip or UPS may be introducing noise)?

Thanks.  I don't think it's overheating.  The room is air conditioned.  It is pluged into a UPS, but shouldn't the battery actually smooth out any power hiccoughs?  ATT says there's no noise on the line.  

The Broadband Stats page info is below. I've also save logs from around the time of outages and can post those too.

IGMP Stats

Multicast

IGMP Querier Version 3
IGMP Robustness 2
IGMP Query Interval 125
IGMP Query Response Interval 100
IGMP Unsolicited Report Interval 10
IGMP Fast Leave Enable on
IGMP Last Member Interval 10
IGMP Last Member Count 2
IGMP Maximum Group Memberships 64
IGMP Default Forward Allow on
IGMP Snooping Entry Time 150
IGMP Snooping Unreg Mode block
IGMP QoS ToS 0xc0
IGMP QoS P Bit 6
IGMP QoS Marker
IGMP Proxy State snoop|fwd
IGMP Snooping Statistics

Port Group Source Timeout
5 239.195.192.3 192.168.1.67 37.31
1 224.0.1.60 192.168.1.76 35.91
Summary

Fwd Grp Num Grp Num Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 1 4 0 0 240 10 963 0
Transmitted 1 4 120 0 0 0 0 0

Interface Group Address Uptime Last Reporter Address Last Reporter Time
Group br2 239.195.192.3 00:04:06:46 192.168.1.129 2016-08-06 10:05:34

Group br2 224.0.0.251 00:04:06:39 192.168.1.198 2016-08-06 10:05:41

Group br2 224.0.1.60 00:04:06:40 192.168.1.76 2016-08-06 10:05:40

Group br2 239.255.255.250 00:04:06:46 192.168.1.76 2016-08-06 10:05:34
Multicast Group Hosts

Host IP Address Uptime Multicast Address
Host 192.168.1.129 00:04:06:41 239.195.192.3
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 240 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.67 00:04:06:45 239.195.192.3
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 242 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.198 00:01:16:09 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 28 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.252 00:01:45:55 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 2 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.158 00:03:23:30 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 15 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.200 00:03:41:17 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 115 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.253 00:03:44:48 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 50 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.195 00:03:59:23 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 32 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.204 00:03:59:25 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 32 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.185 00:04:06:39 224.0.0.251
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 0 0 65 0
Transmitted 0 0 0 0 0 0
Host IP Address Uptime Multicast Address
Host 192.168.1.76 00:04:06:40 224.0.1.60
Query V1 Responses V2 Responses V2 Leaves V3 Responses Other
Received 0 0 240 0 0 0
Transmitted 0 0 0 0 0 0

I just noticed that under Broadband status it lists IPV6 as "available" even though it's turned off and "unavailable" under Home Network. Don't know what to make of that.  Also, there are 29598 FEC Errors, whatever that means.

Broadband Status

Broadband Connection Source DSL

Broadband Connection Up
Broadband IPv4 Address 99.110.189.242
Gateway IPv4 Address 99.110.188.1
MAC Address ***
Primary DNS 68.94.156.11
Secondary DNS 68.94.157.11
Primary DNS Name DNS query timed out
Secondary DNS Name
MTU 1500
DSL Status

Line State Up
Downstream Sync Rate (kbps) 32339
Upstream Sync Rate (kbps) 5041
Downstream Max Attainable Rate (kbps) 66480
Upstream Max Attainable Rate (kbps) 5041
Modulation VDSL2
Data Path Interleaved
Downstream Upstream
SN Margin (dB) 23.0 0
Line Attenuation (dB) 26.9 0
Output Power(dBm) 14.2 -4.4
Errored Seconds 0 0
Loss of Signal 0 0
Loss of Frame 0 0
FEC Errors 29598 0
CRC Errors 0 0
IPv6

Status Available
Global Unicast IPv6 Address 2602:306:36eb:df20::/60
Border Relay IPv4 Address 12.83.49.81
IPv4 Statistics

Transmit Packets 2966101
Transmit Errors 0
Transmit Discards 6
IPv6 Statistics

Transmit Packets 0
Transmit Errors 0
Transmit Discards 0

[Edited for privacy-please do not post personal or unique information such as but not limited to full names, employee ID numbers, email addresses, phone numbers, account numbers, etc.]

Focusing on this information:

Downstream Sync Rate (kbps) 32339
Upstream Sync Rate (kbps) 5041
Downstream Max Attainable Rate (kbps) 66480
Upstream Max Attainable Rate (kbps) 5041
,,,
SN Margin (dB) 23.0 0
Line Attenuation (dB) 26.9 0
Errored Seconds 0 0
Loss of Signal 0 0
Loss of Frame 0 0
FEC Errors 29598 0
CRC Errors 0 0

66 Mbps raw line downstream is great when you only need a 32 Mbps profile, so that would indicate a strong singal.  23.0 SN Margin is good.  Line Attenuation is high considering these other metrics, that's a bit odd.  Your max upstream is equal to your upstream sync rate.  This means either (a) you're on an old card in the VRAD that doesn't report the actual upstream sync rate back to your Gateway, or (b) your upstream sync rate is just barely good enough.

Did your stats say how long a period of time is covered by these statistics?  29.6K FEC (Forward Error Correction, or recoverable errors) just barely makes the specs if your collection time is 5 hours.  If less than 5 hours, it fails the standard and you have a line issue.  If much more than 5 hours (i.e. a day) is quire acceptable, the acceptable standard being 100 FEC / minute.

I'm wondering if your line was ever checked for reflection issues, or a bridge tap.  Have you dealt with ATTU-verseCare?

Thank you.  I don't see anything that says how long the collection time was for the FEC Errors.  How do I find out?

I'm not familiar with ATTU-verseCare.  Is it different than regular ATT support?

@grabacontroller Thanks.  Can you tell me where you see the nat entries?