Cable modems have built-in diagnostics for getting information on the quality of the cable signal coming to the modem. The procedures for accessing these diagnostics vary depending on the brand and model of cable modem you have. If the information below won't get you to these diagnostics, please contact the manufacturer of your cable modem (be it leased or owned). A few modems may have this information in the manual that they came with. For some cable modems, you can access these diagnostics even if the cable modem hasn't obtained block sync.

•The following list is Manufacturer & Model specific. This info. directs you via a link & provides Username / Password where applicable.

Arris CM550A________________ Need Info.
Arris CM820A________________ Need Info.
Arris TG852G (IMS/NCS)_______ Need Info.
Arris TG862G (IMS/NCS)_______ »10.0.0.1./ _______ Username: admin / Password: password
Arris TM402G (IMS/NCS)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM402P (IMS/NCS)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM502G (IMS/NCS)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM504G (IMS/NCS/SIP)___ »192.168.100.1/ ___ No Username or Password required
Arris TM508A (NCS/SIP)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM602G (IMS/NCS/SIP)___ »192.168.100.1/ ___ No Username or Password required
Arris TM604G (IMS/NCS/SIP)___ »192.168.100.1/ ___ No Username or Password required
Arris TM608G (NCS/SIP)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM702G (IMS/NCS)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM722G (IMS/NCS)_______ »192.168.100.1/ ___ No Username or Password required
Arris TM822G (IMS/NCS)_______ Need Info.
Arris WBM760A_______________ Need Info.

Cisco DPC3000___ »192.168.100.1/ ___ No Username or Password required
Cisco DPC3008___ »192.168.100.1/ ___ No Username or Password required

D-Link DCM-301___ Need Info.
D-Link DCM202___ »192.168.100.1/ ___ Username: dlink / Password: dlink
D-Link DCM202 (Comcast firmware)___»192.168.100.1/ ___ Username: admin / Password: hitron

Motorola SB5100____ »192.168.100.1/ ___ No Username or Password required
Motorola SB5101____ »192.168.100.1/ ___ No Username or Password required
Motorola SB5101U___ »192.168.100.1/ ___ No Username or Password required
Motorola SB5120____ »192.168.100.1/ ___ No Username or Password required
Motorola SB6121____ »192.168.100.1/ ___ No Username or Password required
Motorola SB6141____ »192.168.100.1/ ___ No Username or Password required
Motorola SBG6580___ »192.168.0.1/ _____ Username: admin / Password: motorola
Motorola SBG901____ »192.168.0.1/ _____ Username: admin / Password: motorola

Netgear CG3000DCR__ »10.1.10.1/ __ Username: cusadmin / Password: password
Netgear CG814CCR-V2_ »192.168.100.1/ ____ No Username or Password required
Netgear CMD31T______ »192.168.100.1/ ____ Username: admin / Password: password

Scientific-Atlanta DPC2100R2__________ Need Info.
Scientific-Atlanta DPC2203 (IMS/NCS)___ Need Info.
Scientific-Atlanta DPC2203C (IMS/NCS)__ Need Info.
Scientific-Atlanta DPC2203C2 (IMS/NCS)_ Need Info.

SMCNetworks SMC8014WG-CCR_____ Need Info.
SMCNetworks SMCD3G-CCR________ »10.1.10.1/ ___ Username: cusadmin / Password: highspeed
SMCNetworks SMCD3GNV (IMS/NCS)_ »10.0.0.1./ ___ Username: admin / Password: password

Technicolor TC8305C (IMS)___ Need Info.

Thomson DCM425___________ Need Info.
Thomson DHG535 (IMS/NCS)__ Need Info.
Thomson DHG536 (IMS/NCS)__ »192.168.100.1/ ___ No Username or Password required

Ubee DDM3503____________ »192.168.0.1/ _____ Username: user / Password: user or »192.168.100.1/ ___ Username: admin / Password:cableroot
Ubee DDM3513____________ »192.168.0.1/ _____ Username: user / Password: user or »192.168.100.1/ ___ Username: admin / Password:cableroot
Ubee DVM3203B (IMS/NCS)__ »192.168.100.1/ ___ Username: admin / Password:cableroot
Ubee U10C018_____________ »192.168.100.1/ ___ Username: admin / Password:cableroot
Ubee U10C035_____________ »192.168.100.1/ ___ Username: user / Password: user

Zoom Telephonics 5241_______ »192.168.100.1/ ___ Username: admin / Password: cable
Zoom Telephonics 5341(G/H)__ »192.168.100.1/ ___ No Username or Password required / Additional Login: »192.168.100.1/rf_index.asp
Zoom Telephonics 5341J______ »192.168.100.1/ ___ Username: admin / Password: password Additional Login: »192.168.100.1/RgEventLog.asp
Zoom Telephonics 5350_______ »192.168.0.1/ _____ Username: admin / Password: admin
Zoom Telephonics 5352_______ Need Info.

ZyXEL BRG-35503___ Need Info.

•Thanks to all the posters in this thread who helped with updating this FAQ: »I need your help updating a FAQ !!


• If none of the above methods work, or if your cable modem does not have block sync, you may need to 'force' a connection directly to the modem. This is done by:

1) Set the IP of your ethernet connection to 192.168.100.254

2) Set the Subnet Mask of your ethernet connection to 255.255.255.0

3) Leave the Default Gateway and DNS Servers blank.

4) Reboot your PC.

5) Repeat step "1" as necessary.

• IMPORTANT! Be sure to set your ethernet connection back to DHCP (Obtain IP and DNS automatically) and reboot when you are done checking the diagnostics or you won't be able to access the internet!

• Once you have accessed the diagnostics interface in your browser, you need to know which of these statistics are important and what to watch for if you are having difficulties. See the FAQ: What should my signal levels be? for an interpretation of this information.

*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Comcast or any of its affiliates.

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by Kylemaul edited by Johkal
last modified: 2013-05-20 17:09:13