# Surfboard SB3100D, blinking recieve light, no connection



## V0lt (Sep 14, 2002)

Hi everybody,

Yesterday I hooked up my old P5-120MHz Gateway 2000 to my Surfboard SB3100D cable modem by way of the ethernet card I installed on that computer. It worked great for about 5 minutes, and stopped working completely after I restarted that computer. After hooking the modem back to the USB on my new computer, the modem fails to connect, and the only thing it does is sit there with the receive light flashing. I've tried connecting it to my computer through the PCI ethernet, but that doesn't work either. I called Comcast support, and they did not know what was wrong. 

No ping, no activity at all. 

Please help or this could be my last post here for the entire summer.

edit: I've already tried unplugging it for 5 minutes, no luck there. Reset button doesn't help either.


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## Guest (Jun 11, 2003)

What OS are you using?


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## V0lt (Sep 14, 2002)

I'm using windows 98. 

It does not seem to be a problem with my computer, but the modem instead.


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## Guest (Jun 11, 2003)

Try Start, Run and type in ipconfig.exe then enter.

If I remember correctly a box should pop up. Select release all then renew all and see if your ip address is there. Sorry it's been a long time since I messed around with 98..............:| 

If the first number is 168.xxx.xxx.xxx I do believe that would be the Microsoft number and not your IP number.


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## V0lt (Sep 14, 2002)

I've attached a screen shot of the ip configuration (it's actually winipcfg.exe in win98). The subdomain of the host name is actually my computer's name in networking (I don't have a network set up, but that's what it says it is in network ID properties). The IP address seems to be a non-external one. I do not think that this modem is connecting at all.


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## Guest (Jun 11, 2003)

Call Comcast and tell them that this number is showing up in your configuration window and that it doesn't look familiar.


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## johnwill (Sep 26, 2002)

What I'm seeing is the indications you get when you have a broadband router in the mix. Note that 192.168.xxx.xxx addresses are private LAN addresses. When I directly connect my cable modem to a PC, I get my real Internet IP address, not a private network address. I believe your modem is a standard DOCSIS compliant modem, so that behavior is odd to say the least. 

You don't happen to have ICS configured, do you?


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## Guest (Jun 11, 2003)

I thought the same thing when I checked the IP addy, But he didn't mention a router so I said "what the hey".........


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## johnwill (Sep 26, 2002)

Since I see a DHCP server address, I can only assume that it's indeed configured for DHCP and has obtained an address that way.


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## V0lt (Sep 14, 2002)

Well, I am almost sure that I don't have ICS set up (I never had a reason to start ICS), and I'm positive that I don't have a router. The oddest thing is that when I took the modem up into my room, it worked when plugged into the cable connection there (Instead of flashing the "receive" light, it held steady and the send and online lights came on as well). I have called Comcast support and they had absolutely no idea what was going on. They said they could not communicate with my modem, and that they were seeing a lot of interference on our line. In any case, they are sending out a tech to look at everything today, so this may be resolved soon. 

Thanks for your help so far.


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## johnwill (Sep 26, 2002)

Please post the resolution to the problem, I'm very curious how the private LAN IP address gets there.


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## V0lt (Sep 14, 2002)

Hi all,

The tech that came just fixed the problem. It turns out that the splitter that feeds the coaxial outlet to which my cable modem is connected had gotten water in it, so Comcast has to send another person over to take out and replace that line. 

I'm not sure where the private IP came from, but I'm thinking that the cable modem might have given that to my computer automatically when it couldn't find a connection.


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## Guest (Jun 12, 2003)

Well at least it fixed................. 

And look at all the fun you had here...................:winkgrin:


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## johnwill (Sep 26, 2002)

I have two cables from the street to my house, and a patch panel at the service entrance. I also have two coax runs up to my office where the cable modem lives. If I suspect issues with the feed, I can replace it all the way from the street.  Normally, the second run goes to my TiVo so I can remote control it and see what it's doing.


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## ian2000611 (May 21, 2006)

*Private IP Explination*

Some TCPIP stacks (including microsofts) will asign a 192.168.x.x ipaddress if the network adapter could not connect to a dhcp server, and it sounds like that is what happened in this case.


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