Hooking up a laptop to a cable modem

Post #48,024 by bluke 8/4/02 9:29:17 AM 8/4/02 9:32:31 AM Reply	Hooking up a laptop to a cable modem I was recently visiting my parents and wanted to hook my laptop up to their cable modem (which is usually hooked up to their desktop machine). It looks like straight DHCP, but my laptop (Win 2000) couldn't connect to the DHCP server (while as soon as I plugged the desktop back in it worked fine). They have Road Runner from their local cable company. I looked on their web site for configuration info but there was none there. Anyone have experience with Road Runner? Any suggestions? I will be staying at my parents for awhile in the near future and would really like to be able to hook up my laptop there and do some work. Any help is appreciated. Edited by bluke Aug. 4, 2002, 09:32:31 AM EDT Expand All History
Post #48,028 by pwhysall 8/4/02 10:38:03 AM Reply	Re: Hooking up a laptop to a cable modem Plug the laptop in. Open a command prompt. Issue this sequence of commands: ipconfig /release ipconfig /renew ipconfig /flushdns Does this help? Peter [link\|http://www.debian.org\|Shill For Hire] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Blog]
Post #48,095 by bluke 8/5/02 2:57:37 AM Reply	Re: Hooking up a laptop to a cable modem I tried those and it didn't work. Anyone have any ideas how I can find out if Road Runner uses the MAC address of the network card? BTW, how do I find out what the MAC address of the network card is?
Post #48,106 by pwhysall 8/5/02 7:22:55 AM Reply	MAC addresses There are two ways. Physically inspect the card. the MAC address is usually printed on the card. Run "ipconfig /all" and observe the output: Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : 3Com 3C920 Integrated Fast Ethernet Controller (3C905C-TX Compatible) Physical Address. . . . . . . . . : 00-06-5B-26-F8-6C Dhcp Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 10.200.1.50 Subnet Mask . . . . . . . . . . . : 255.255.0.0 Default Gateway . . . . . . . . . : 10.200.1.1 This is a snippet of the configuration of my desktop PC at work. the MAC address is the "Physical Address". Note that some network cards allow you to change this. Peter [link\|http://www.debian.org\|Shill For Hire] [link\|http://www.kuro5hin.org\|There is no K5 Cabal] [link\|http://guildenstern.dyndns.org\|Blog]
Post #48,031 by Andrew Grygus 8/4/02 10:57:46 AM Reply	Cable tricks Cable companies around here key the service to the MAC address of the network card in the computer they set up. To connect any other computer, it is necessary to determin the MAC address of the original computer's card and force the other computer to that address. We usually do this with Linksys router (now down to $70 or so), since it has MAC address spoofing built in. [link\|http://www.aaxnet.com\|AAx]
Post #48,062 by a6l6e6x 8/4/02 6:14:40 PM Reply	Yep, with Linksys router, on Road Runner cable modem (and only single IP from RR) I run often run 2 Windows (one 98, one ME) and two Linux boxes simultaneously. Alex "Television: chewing gum for the eyes." -- Frank Lloyd Wright
Post #48,069 by folkert 8/4/02 7:24:55 PM 8/4/02 7:26:03 PM Reply	Power Cycling the Cable Modem... Has worked on more than one occasion for me and others I "support". The MAC address issue eluded to by others is usually about the MAC addr on the Cabal(hehe;) modem itself. that and the stuff Peter Whysall mentioned should fix it up fer ya. edit: Damned mind playing tricks on me. `greg - Grand-Master Artist in IT, curley95@attbi.com -- REMEMBER ED CURRY!!!` Edited by gfolkertold Aug. 4, 2002, 07:26:03 PM EDT Expand All History
Post #48,072 by Andrew Grygus 8/4/02 8:32:55 PM Reply	No, it is the network card - and . . . . . the installer generally records that MAC address on the paperwork given to the customer, at least in these parts. Hook any device with a different MAC address to the cable modem, and it will not connect. If this were not an issue, the routers would not have had MAC spoofing added (originally they didn't have it). [link\|http://www.aaxnet.com\|AAx]
Post #48,077 by folkert 8/4/02 10:08:02 PM Reply	From a know-nothing... Well, I guess I know nothing then... Then explain how I have hooked up about 30 different NICs to my CABAL modem... Have had the ability to do the same at many others around here in Michigan... And anytime the Modem has been replaced... then the Modem's MAC has to be "activated"... Never been a problem around here. I guess I just am lucky `greg - Grand-Master Artist in IT, curley95@attbi.com -- REMEMBER ED CURRY!!!`
Post #48,087 by Andrew Grygus 8/4/02 11:21:31 PM Reply	Easy Not all cable companies key to the MAC address. If your's doesn't then there isn't even a reason for you to know about MAC spoofing except as an item of arcane but useless knowledge. Around here they do, so nobody's going to connect anything through the cable modem except the original NIC unless it spoofs that NIC's MAC. I've seen people try. [link\|http://www.aaxnet.com\|AAx]
Post #48,110 by ben_tilly 8/5/02 8:09:32 AM Reply	power-cycling the modem is worth trying though If you don't know whether or not it will work, it is worth a shot. For the record here (roadrunner, NYC) it does. Cheers, Ben "Perl is like vice grips. You can do anything with it, and it's the wrong tool for every job." --Unknown
Post #48,111 by ben_tilly 8/5/02 8:12:21 AM Reply	Bad tech support. BAD! BAD! You assume that it is the network card, and you assume that a simpler solution will not work. And then jump to a much more complicated solution. At least try the easy solution. If it doesn't work, it doesn't work. But in much of the country it will, and is easy enough to test. Cheers, Ben "Perl is like vice grips. You can do anything with it, and it's the wrong tool for every job." --Unknown
Post #48,129 by Andrew Grygus 8/5/02 10:14:39 AM Reply	No, what I assume is . . . . if he's someone who posts here, he's already power cycled everything. Even some of my customers have enough sense to do that (though admittedly, not many). [link\|http://www.aaxnet.com\|AAx]
Post #48,231 by folkert 8/5/02 5:50:00 PM Reply	Well... I'll give you that.... It should be reasoned that if they do post here... BUT... on more than one occasion... I have seen even VERY good troubleshooters troubleshoot RIGHT past the simple fixes and assume the more complex ones... and I admit... even I have done that.... ----hush-hush---- shhhh.... don't let that out... So, it always does help to at least "mention" the easy fixes... as we all know those "Dam, I coulda had a V8" moments happen. `greg - Grand-Master Artist in IT, curley95@attbi.com -- REMEMBER ED CURRY!!!`
Post #48,249 by ben_tilly 8/5/02 7:17:21 PM Reply	Another bad assumption First of all Bryce posts here. Secondly we all have different skillsets. What is common sense for one is unlikely to be for everyone else. For instance I don't work with hardware much. Sure, I know to try power-cycling everything. How? Because I know someone who had a lot of problem getting everything set up with her cable modem, and when I was going to get one I asked the guy who got it working, "BTW what was the problem you mentioned with Kim's modem?" "Oh, turns out that you have to power-cycle the modem every time you want to change what it is connected to." So I know it. Now. But didn't 6 months ago. And I don't assume that people know what I just learned... Cheers, Ben "Perl is like vice grips. You can do anything with it, and it's the wrong tool for every job." --Unknown
Post #48,303 by static 8/6/02 1:47:55 AM Reply	I told a tech off for suggesting that. What happened is that when he suggested power-cycling it, I said "that shouldn't be necessary" and he agreed. This was a DSL modem that took 90 seconds to boot, did the PPPoE itself, had a basic firewall capability and a 4-port hub built-in. It didn't fix the problem, anyway. Power-cycling computing hardware "just to see if it fixes it" is a Windows mentality. Curiously, when I flashed my 802.11b Access Point, the readme file said to power-cycle it, but by the time I read that, it had finished flashing and was running the new firmware! Wade. "Ah. One of the difficult questions."
Post #48,334 by ben_tilly 8/6/02 7:19:50 AM Reply	This isn't a case of Windows mentality The issue with many cable modems is that there is no way built into the modem to cause it to do basic reinitializations (like "figure out what name the hardware that is attached to me expects to hear itself addressed by") is to start from scratch. So if you switch what you have plugged into the modem, then you need to power-cycle or they will forever talk past each other. Once it is up, then barring a hardware change you can leave it that way for months. Cheers, Ben "Perl is like vice grips. You can do anything with it, and it's the wrong tool for every job." --Unknown
Post #48,355 by admin 8/6/02 10:20:38 AM Reply	Not only that... ... but my cable modem doesn't even have a power switch. So if something changes to the point where it needs reinitialization (like when Comcast changed to their own network from @home), I have to unplug it, then plug it back in. :-) Regards, -scott anderson "Welcome to Rivendell, Mr. Anderson..."
Post #48,410 by a6l6e6x 8/6/02 2:42:27 PM Reply	Also, a power glitch can put the cable modem into limbo. Had that happen once. A short power disruption left the Motorola cable modem in a weird state that made it look like there was no cable signal. The Road Runner tech support guy suggested power off/power on before sending out a repair guy. Good thing! Duke Energy (the local power company) is notorious for power blips so my cable modem is now on a small UPS. Alex "Television: chewing gum for the eyes." -- Frank Lloyd Wright
Post #48,419 by Andrew Grygus 8/6/02 3:01:00 PM Reply	Happens to hubs too. I've had to power cycle 10BaseT and 10/100 hubs that jammed because of a power fluctuation. Everything looks fine, but some (or all) of the ports don't work. [link\|http://www.aaxnet.com\|AAx]
Post #48,309 by bluke 8/6/02 3:19:50 AM Reply	Just received an answer from RR tech support Whoever said to power-off the modem was right. Here is their answer: "Power cycle your modem. Power cycling will reset the modem to start from the beginning. Power cycling the modem is to unplug the power cord (if you look at the back of the modem you will see a black power cord) from the wall outlet or power bar. Wait 2 full minutes prior to plugging it back in. Wait another full minute before proceeding. Close all programs on your computer and reboot it. "
Post #48,612 by folkert 8/7/02 8:33:10 PM Reply	Nope... Not going there except to.... Maybe poke at [link\|http://www.aaxnet.com/images/ajg47d.jpg\|This guy] from [link\|http://www.aaxnet.com\|this place]. Ain't to often you best that guy... GRIN `greg - Grand-Master Artist in IT, curley95@attbi.com -- REMEMBER ED CURRY!!!`

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