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How to tell if my modem, router, or comcast is the problem.

Frequent Visitor

How to tell if my modem, router, or comcast is the problem.

My internet is constantly going out. Several times a day. I've had comcast out, they just tell me its my fault, my wiring (all brand new they installed) my house, who knows. Anyway, I was thinking it was my router, but before I invest in one of the expensive ones (right now just a basic linksys) I'm wondering if theres a way to tell if that is the issue. When it goes out, if I reset the router it does come back. The lights on the modem never go out when the internet is out.

I looked up the modem configuration, no idea what any of this means but maybe its helpful...

 

Frequency 627000000 Hz Signal To Noise Ratio 38.3 dB Power Level -3.4 dBmV
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

 

Upstream ValueChannel ID 10 Frequency 23600000 Hz Power 48.9 dBmV

 

Frequency Plan North American Standard/HRC/IRC Upstream Channel ID 10 Frequency (Hz) 627000000 DHCP Server Enabled

 

 

 

2014-03-14 18:23:44 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 18:23:40 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 15:35:54 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 15:35:52 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 15:35:38 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 15:35:34 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 14:54:48 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 14:54:46 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 14:54:32 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 14:54:04 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 14:15:30 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 14:15:28 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 14:15:14 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 14:15:10 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 07:50:53 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 07:50:51 6-Notice M571.0 Ethernet link down - not ready to pass packets 2014-03-14 07:50:37 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-14 07:50:31 6-Notice M571.0

Ethernet link down - not ready to pass packets

 

Silver Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.

What are the mak and model numbers of your router and modem. The log entries appear to show an intermittent loss of connectivity on the ethernet interface that connects the modem to the router. If either of the devices are old, then it could be a failing ethernet interface. Or more simply, a bad cable between the modem and the router.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I don't work for Comcast...


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Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.

Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

Router is Linksys WRT160N I want to say 3 years old?
Modem is Motorola Surfboard SB5101U Apx 2 years old.

Silver Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.


kristina3150 wrote:

Router is Linksys WRT160N I want to say 3 years old?
Modem is Motorola Surfboard SB5101U Apx 2 years old.


They are not too old, so there is a good chance it is not a problem with either the Internet interface in the router or the ethenet interface on the modem (either or both are still a possibility). First, I would try swapping out the ethernet cable between the devices, to see if the issue goes away. If it doesn't we can try to eliminate the router and modem through a process of elimination.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I don't work for Comcast...


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Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

Okay, I will go get a new ethernet cable and report back in a day or so Smiley Happy

Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.

If you have a local mom & pop computer store, they may have them cheaper then Best Buy. It does not matter if it states Cat-5e or Cat-6. Just make sure you get one long enough. Also Lowe's, Home Depot and Ace Hardware stores sell the cords.
Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

So0o I got a new ethernet coard and the internet seems more stable. However, I went back into the modem logs and am getting a whole new weird error. See below. What gives?

 

2014-03-17 11:21:53 6-Notice M573.0 Modem Is Shutting Down and Rebooting... 2014-03-17 11:21:53 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o 2014-03-17 11:21:21 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out 1970-01-01 00:00:08 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-17 10:39:18 6-Notice M573.0 Modem Is Shutting Down and Rebooting... 2014-03-17 10:39:18 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o 2014-03-17 10:39:17 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing 2014-03-17 10:34:32 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out 2014-03-17 10:25:25 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing

Silver Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.


kristina3150 wrote:

So0o I got a new ethernet coard and the internet seems more stable. However, I went back into the modem logs and am getting a whole new weird error. See below. What gives?

 

2014-03-17 11:21:53 6-Notice M573.0 Modem Is Shutting Down and Rebooting... 2014-03-17 11:21:53 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o 2014-03-17 11:21:21 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out 1970-01-01 00:00:08 6-Notice M571.1 Ethernet link up - ready to pass packets 2014-03-17 10:39:18 6-Notice M573.0 Modem Is Shutting Down and Rebooting... 2014-03-17 10:39:18 3-Critical R004.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o 2014-03-17 10:39:17 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing 2014-03-17 10:34:32 3-Critical R005.0 Started Unicast Maintenance Ranging - No Response received - T3 time-out 2014-03-17 10:25:25 3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing


Post your modem signal levels...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I don't work for Comcast...


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New Poster

Re: How to tell if my modem, router, or comcast is the problem.

Stay to channels 1, 6 or 11. 10 will overlap channel 6 which is not good with a router. Did you buy your modem new or is it one that Comcast  pulled from a returned equipment box?

Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

My router is and always has been set to channel 11 - Is this modem diagnostic saying something different?

 

Modem was purchased new and is owned, not comcast equipment.

Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

Oh Nevermind, I just checked my router and it got switch back to "auto" channel at some point when I was messing with settings. I put it back to 11 & will keep an eye on it.

New Poster

Re: How to tell if my modem, router, or comcast is the problem.

Run a tracert command to a distant server and look at the results. I did and I found the issue was not with my wireless card, my 6 computers, or my modem. I found servers along the route that were down and causing issues. More than likely you have the same problem reaching an address.

 

Tracing route to us.battle.net [12.129.242.40]
over a maximum of 30 hops:

1 2 ms 2 ms 2 ms 10.0.0.1
2 48 ms 30 ms 78 ms 50.180.194.1
3 18 ms 19 ms 16 ms xe-10-3-0-32767-sur01.b5mableton.ga.atlanta.comcast.net [68.86.109.129]
4 12 ms 17 ms 12 ms xe-10-0-0-0-ar01.b0atlanta.ga.atlanta.comcast.net [68.85.108.185]
5 18 ms 20 ms 55 ms he-5-13-0-0-11-cr01.56marietta.ga.ibone.comcast.net [68.86.93.205]
6 * * * Request timed out.
7 13 ms 24 ms 22 ms as7018-pe01.56marietta.ga.ibone.comcast.net [75.149.228.86]
8 79 ms 73 ms 77 ms cr1.attga.ip.att.net [12.122.141.182]
9 110 ms 73 ms 90 ms cr2.dlstx.ip.att.net [12.122.28.174]
10 94 ms 88 ms 68 ms cr2.la2ca.ip.att.net [12.122.28.178]
11 98 ms 65 ms 62 ms gar29.la2ca.ip.att.net [12.122.129.241]
12 65 ms 61 ms 72 ms 12-122-254-238.attens.net [12.122.254.238]
13 64 ms 73 ms 95 ms mdf001c7613r0002.lax1.attens.net [206.16.68.54]
14 * * * Request timed out.
15 * * * Request timed out.
16 * * * Request timed out.
17 * * * Request timed out.
18 * * * Request timed out.
19 * * * Request timed out.
20 * * * Request timed out.
21 * * * Request timed out.
22 * * * Request timed out.
23 * * * Request timed out.
24 * * * Request timed out.
25 * * * Request timed out.
26 * * * Request timed out.
27 * * * Request timed out.
28 * * * Request timed out.
29 * * * Request timed out.
30 * * * Request timed out.

Trace complete.

 

See just bad service not bad hardware.

 

Silver Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.

While the modem you have may still work for a while, it has been on the end of life list since December. You really should consider getting a DOCSIS 3 modem, such as the SB6141 or Zoom 5341J.

 

http://mydeviceinfo.comcast.net/device.php?devid=224

Silver Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.


javapro wrote:

Run a tracert command to a distant server and look at the results. I did and I found the issue was not with my wireless card, my 6 computers, or my modem. I found servers along the route that were down and causing issues. 

 


Tracert time outs are not necessarily an indication of problems. routers, firewalls or servers along the path from your computer to a remote server may be configured to drop or selectively respond to the ICMP packets that tracert uses, That does not mean that more 'standard' Internet traffic (such as http/https, etc) would be dropped or de-prioritized.

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I don't work for Comcast...


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Gold Problem Solver

Re: How to tell if my modem, router, or comcast is the problem.


javapro wrote: ... I found servers along the route that were down and causing issues. ...

What Paranoid and kevj said. Also see http://forums.comcast.com/t5/Basic-Internet-Connectivity-And/Just-a-point-about-packet-loss-complain...

Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

Okay, So I went and bought new DOCIS3 modem. SB6121 was all they had at the store. I'm still having outages. Here are the logs & stats

 

 

Channel ID 1  3  6  7 

Total Unerrored Codewords 1285191669  1285191671  1285191674  1285191675 

Total Correctable Codewords 11  14  14  12 

Total Uncorrectable Codewords 641  635  636  638 

 

Upstream

Channel ID 10  11  12 

Frequency 23600000 Hz  31000000 Hz  36000000 Hz 

Ranging Service ID 8382  8382  8382  Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  2.560 Msym/sec  Power Level 47 dBmV  49 dBmV  49 dBmV 

Upstream Modulation [3] QPSK
[3] 64QAM
  [3] QPSK
[3] 64QAM
  [3] QPSK
[2] 16QAM
  Ranging Status Success  Success  Success

 

Downstream

Channel ID 1  3  6  7 

Frequency 591000000 Hz  603000000 Hz  621000000 Hz  627000000 Hz 

Signal to Noise Ratio 37 dB  37 dB  37 dB  38 dB 

Downstream Modulation QAM256  QAM256  QAM256  QAM256 

Power Level The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading 0 dBmV   0 dBmV   0 dBmV   0 dBmV  

 

Custom Frequency Ordering: Default Upstream Channel ID: 10 Favorite Frequency (Hz) 591000000 DOCSIS MIMO Honor MDD IP Mode Modem's IP Mode IPv6 Only

 

Apr 02 2014 09:16:59 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:00:13 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

 

Apr 01 2014 23:42:44 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:00:13 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

Apr 01 2014 23:03:43 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:00:13 6-Notice N/A Cable Modem Reboot due to IP loss ;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

 

Apr 01 2014 23:01:08 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=b0:77:ac:29:47:ac;CMTS-MAC=00:01:5c:23:a4:44;CM-QOS=1.1;CM-VER=3.0;

Frequent Visitor

Re: How to tell if my modem, router, or comcast is the problem.

$150 later I have a new Ethernet Cable, New Modem and New Router. Problem is gone. Assuming since I changed the router last, it was the issue. So I guess the answer to my initial question is, process of elimination.