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New Visitor
SLBart
Posts: 4
Registered: ‎09-15-2013

Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router

I have been using a Netgear N300 router with AT&T DSL. I have had my computer and Sony Blu-ray player plugged into the router (a wireless router with wired capability), and the router hardwired into the DSL modem via Ethernet cable. I just signed up for XFINITY Blast! Plus Internet today, to which end I purchased a Motorola SURFboard SB6121 DOCSIS 3.0 cable modem. The TV (XFINITY cable) and modem are connected to the wall outlet via a coax splitter. I unplugged the DSL modem from the router and plugged in the SURFboard SB6121. When I called Comcast Tech Support to activate the SURFboard modem and give them the MAC ID, the tech was unable to get the modem online, even though he sent the commands several times. All of the top 4 lights on the modem (Power, Receive, Send and Online) stayed on solid and displayed the correct colors. The Link light (bottom one, signals transmitting data) was flashing red (it was supposed to be either amber or blue, for either regular or Gigabit Ethernet connection).

 

Nothing he tried would get the modem online. He finally decided there was a problem with his computer system and had me call Comcast Signature Support at a different number, saying they had different tools at their disposal. I did so, and the girl I spoke to tried to send the commands, then had me unplug the power and Ethernet cables for one minute before reconnecting them. No go. Then she had me disconnect the modem from the router and connect it directly to the computer. To do so, I had to disconnect the computer from the router, since the computer's Ethernet port now had to take the cable to the modem instead of a cable to the router. Voila - everything came up immediately, and a speed test showed I was getting 57.75 Mbps download and 11.79 Mbps upload.

 

That's great, except for one thing. With the modem plugged directly into the computer, the router is now connected to nothing. Which means that my Internet Blu-ray player, with my streaming Netflix, YouTube and many other media items, is no longer connected to the Internet.

 

Has anyone ever heard of this problem before? Any suggestions on how to overcome it?

 

Also, while I'm asking... the tech said that plugging the modem into the router instead of into the computer will automatically cut the speed in half, because even though it is hardwired, it behaves like it is wirleless. Is this true? If so, it's a major drawback to having a wireless router that I've never heard of before.

Bronze Problem Solver
Posts: 1,335
Registered: ‎11-16-2003

Re: Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router

[ Edited ]

Only answering some of all that ....

What is pluged in to the Lan (ethernet) side of the Moto6121 has nothing to do with the modem being activated-provisioned. The modem can be activated with nothing plugged into the Lan side of the modem. Its best to plug the modem directly into the wall outlet while activation takes place. After activation the modem can then be reconnected to a spliter & signal levels checked. After activation the modem can boot or reboot & be operational, also regardless of what is plugged or not plugged into the Lan side of the modem.

Its kinda sad but too often CSR's fail at activating a modem, (lack of training and understanding?)

A new first time activated modem most always needs a firmware update. In some cases the firmware in the new modem needs to be downgraded to the current Comcast firmware version, (uncertain about that part). If a simple activation is done & only remote reset signals are sent to the modem, the modem can take up to an hour or more of timing out and rebooting to reach its max retries, at which point a firmware update then takes place, (is solicited the correct word?). If a Comcast 'Tech' manually 'pushes' a firmware update, activation & that process can be completed in several mins while you are on the phone with them.

Routers when hard wired to the modem and also hard wired to the PC do not "automatically cut the speed in half", however a router's settings and cabilities, along with the ethernet card's settings and capabilities, can limit throughput to the max bandwidth they are capable of handling, or are configured to handle.

.

Connection Expert
EG
Posts: 43,087
Registered: ‎12-24-2003

Re: Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router


dj280 wrote:

Its best to plug the modem directly into the wall outlet while activation takes place. After activation the modem can then be reconnected to a spliter & signal levels checked.


FWIW, that is not necessarily so if the stats are in spec with the splitter's in place. Removing them could cause the downstream power to be too high / out of spec. YMMV.

Bronze Problem Solver
Posts: 1,335
Registered: ‎11-16-2003

Re: Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router



EG wrote:

dj280 wrote:

Its best to plug the modem directly into the wall outlet while activation takes place. After activation the modem can then be reconnected to a spliter & signal levels checked.


FWIW, that is not necessarily so if the stats are in spec with the splitter's in place. Removing them could cause the downstream power to be too high / out of spec. YMMV.


 

 Ahhh indeed EG, thanks for reminding me.   :smileyhappy:

 

.

New Visitor
SLBart
Posts: 4
Registered: ‎09-15-2013

Re: Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router


dj280 wrote:

Its kinda sad but too often CSR's fail at activating a modem, (lack of training and understanding?)

dj280 got it in one.

 

After a Comcast supervisor couldn't figure it out he escalated me to their Signature Support that deals with wireless and routers. Even after he gave the tech all of our account info, and I told the tech that I had already called in the MAC ID and the modem had been activated but just wouldn't work with the router, the tech still couldn't find our information. Turns out that there is an entire equipment page in Comcast's system that's supposed to be filled out when you call in your MAC address to activate your modem that the girl I spoke to for that never filled out, so they had no record of it and the process was never completed properly. The Signature Support tech, Eric, fixed it in short order, had me do a hard reset of the router, and now everything is back connected to the router and working perfectly.

Connection Expert
EG
Posts: 43,087
Registered: ‎12-24-2003

Re: Motorola SURFboard SB6121 cable modem & Netgear N300 WNR2000 router

Watch your next bill. The third party Signature Support service typically charges $.