Help: Cable Internet Connection Problems (with modem logs)

[R_Willis]

Lately, the last 4-5 days or so my connection has been VERY flakey. It'll work for a couple hours, then not work. Or it might work for 5min, then not work for a few hours. Usually get "limited or no connectivity" popups. The fact that it will work perfectly fine for awhile, then not, has me thinking the problem is PROVIDER related.

I'm using a Motorola Surfboard 5120 modem, NO router, and TWC (formerly Adelphia) cable internet service. WinXP (w/ all updates), Norton Anti-Virus/Security 2006, etc. No other computer problems currently.

I've tried unplugging the cable modem and rebooting it a few times. I've tried a few new network cables. Nothing changes.

Any ideas? I'm kind of stumped. When doing an IPconfig in DOS should my IP and gateway be different numbers?

Here is a copy of my most recent modem logs.

Downstream/Value
Frequency / 561000000 Hz
Signal to Noise Ratio / 37 dB
QAM / 256
Network Access Control Object / ON
Power Level / 6 dBmV

Upstream / Value
Channel ID / 7
Frequency / 32000000 Hz
Ranging Service ID / 3785
Symbol Rate / 2.560 Msym/s
Power Level / 51 dBmV


061029042917 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061029042916 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028234155 3-Critical R02.0 No Ranging Response received - T3 time-out

061028233830 3-Critical R02.0 No Ranging Response received - T3 time-out

061028231634 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028231633 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028231555 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028231554 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230854 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230854 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230550 7-Information SNMP: Working in SNMP V1/2c Only NmAccess mode

061028230548 7-Information INITIALIZATION COMPLETE - MODEM IS OPERATIONAL

061028230548 7-Information 7 I500.0 Registration Completed

061028230548 7-Information Standby mode disabled

061028230548 7-Information SEC: Co-Signer CVC from configuration file was verified

061028230546 7-Information REGISTRATION COMPLETE - Waiting for Operational status

061028230545 7-Information B401.0 Authorized

061028230545 7-Information REG: Capability type <12> isn't supported by CMTS

061028230545 7-Information 7 D509.0 Retrieved TFTP Config SUCCESS

061028230545 7-Information Registration file - downloaded

061028230544 7-Information Trying to download Configuration file ...

061028230544 7-Information 7 D507.0 Retrieved Time....... SUCCESS

061028230544 7-Information Time of day - retrieved

700101000013 7-Information 7 D511.0 Retrieved DHCP .......... SUCCESS

700101000013 7-Information DHCP - parameters acquired

700101000009 7-Information 7 T500.0 Acquired Upstream .......... SUCCESS

700101000009 7-Information Trying to register through CMTS...

700101000009 7-Information SYNCHRONIZED - 561000000 Hz , ucd 7

700101000008 7-Information Starting Ranging On Channel 7

700101000004 7-Information Downstream Locked - Collecting Upstream Information

700101000004 7-Information 7 T501.0 Acquired Downstream (561000000 Hz)........ SUCCESS

700101000002 7-Information Scanning frequency 561000000Hz

700101000001 7-Information Trying to synchronize ...

700101000001 7-Information Vendor Cold Start

061028230333 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230332 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230319 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230318 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230318 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230316 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230315 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230314 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028230313 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225914 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225913 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225721 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225720 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225523 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225523 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225039 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028225038 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028224814 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028224813 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028222928 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028222927 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028221258 3-Critical R02.0 No Ranging Response received - T3 time-out

061028221209 3-Critical R02.0 No Ranging Response received - T3 time-out

061028210800 3-Critical R02.0 No Ranging Response received - T3 time-out

061028203317 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202946 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202929 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202913 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202911 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202736 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202549 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202547 3-Critical R02.0 No Ranging Response received - T3 time-out

061028202545 3-Critical R02.0 No Ranging Response received - T3 time-out

061028201317 3-Critical R02.0 No Ranging Response received - T3 time-out

061028201315 3-Critical R02.0 No Ranging Response received - T3 time-out

061028200727 3-Critical R02.0 No Ranging Response received - T3 time-out

061028200107 3-Critical R02.0 No Ranging Response received - T3 time-out

061028183805 3-Critical R02.0 No Ranging Response received - T3 time-out

061028180943 3-Critical R02.0 No Ranging Response received - T3 time-out

061028180213 3-Critical R02.0 No Ranging Response received - T3 time-out

061028175056 3-Critical R02.0 No Ranging Response received - T3 time-out

061028171538 3-Critical R02.0 No Ranging Response received - T3 time-out

061028164358 3-Critical R02.0 No Ranging Response received - T3 time-out

061028164232 3-Critical R02.0 No Ranging Response received - T3 time-out

061028161640 3-Critical R02.0 No Ranging Response received - T3 time-out

061028084125 3-Critical R02.0 No Ranging Response received - T3 time-out

061028055741 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028055740 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028050047 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028050046 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028045851 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028045850 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028044129 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028044128 4-Error IGMP: ERROR - Group address 0.0.0.1 is not a legal multicast

061028044125 7-Information SNMP: Working in SNMP V1/2c Only NmAccess mode

061028044123 7-Information INITIALIZATION COMPLETE - MODEM IS OPERATIONAL

061028044123 7-Information 7 I500.0 Registration Completed

061028044123 7-Information Standby mode disabled

061028044123 7-Information SEC: Co-Signer CVC from
configuration file was verified

061028044121 7-Information REGISTRATION COMPLETE - Waiting for Operational status

061028044120 7-Information B401.0 Authorized

061028044120 7-Information REG: Capability type <12> isn't supported by CMTS

061028044120 7-Information 7 D509.0 Retrieved TFTP Config SUCCESS

061028044120 7-Information Registration file - downloaded

061028044119 7-Information Trying to download Configuration file ...

061028044119 7-Information 7 D507.0 Retrieved Time....... SUCCESS


Thanks for any help, as always!!

[JamesO]

Your downstream signal information is fine, however, your upstream transmit power is too high. Most most modems top out at 52 dBm, yours is operating and 51 dBm.

This means that if there is any variation in the cable plant return system, your modem only has about 1 dB of transmit power headroom, clearly not enough.

You should date and timestamp this information for future comparison.

I prefer to configure the cable modem directly after a 2 way splitter coming into the house. Cable modem on 1 leg, TV's split off the the other leg.

The problem is most cable TV amps do not amplify in both directions. just in the downstream direction.

If you have changed nothing on your house, then I would assume the problem is the cable companies. Also note that signal level is not always the issue. Lately most providers have been oversubscribing parts of their network causing latency and delays for end users.

JamesO