Comcast internet and router troubles

Discussion in 'Mac Basics and Help' started by jaygriffith, Jul 4, 2008.

  1. jaygriffith macrumors newbie

    Joined:
    Jul 4, 2008
    #1
    I've spent hours today and the days prior trying to get both my Macs up on the internet at the same time. I can get either one to work independently through the router, but not together. My Vonage isn't working either, but that's another matter.

    So, a new Comcast approved Motorolla modem and Linkseys router (thanks to Mark) later, I'm still not getting both computers to work on the internet at the same time. (They used to, before our router went bad). We thought it was the modem so replaced it first.

    Here's the configuration: Comcast Cable into utility room > Cable Modem in said room > to wall outlet upstairs in kitchen > to router > to phone modem and upstairs and downstairs computers.

    Comcast hasn't been real helpful. They did come and determine that the router was the problem though.

    From my investigation I see that I cannot have an IP address beginning with 169. and that Comcast assigns an IP address each time I start up one of the computers. The router though is supposed to create a fake number so that the modem (or Comcast) only sees one computer. Something like that. Below are articles on it. So I took the IP and router address off the one computer I had the internet working on and manually put it on the other--keeping the router number the same but changing the IP to .13 at the end. The IP was .1, the router was .12. Then I shut off the computers, the router, the modem, and turned them all back on in opposite order (modem, etc.) Still same problem.

    I'm obviously missing something here. It all used to work fine so I don't know what has happened.

    How do I configure the router? One link said to configure the router to act as a "NAT" device so that it will appear that all traffic is coming from the router.

    Another person said this: "Who is your internet service provider? I know certain ones (including Comcast) require that the router clone the MAC address of your computer's ethernet port in order for the router to get an IP address. Most routers have a setting that will let you do this."

    Here's more about that direction (scroll down a bit): http://www.daniweb.com/forums/thread32833-2.html

    So I found this info on how to do this cloning, but I can't get the IP # suggested for Linksys in the browser window to load. Says "page can't be found."

    I'm not even sure that is the problem, because I can get either computer to work through the router, just not at the same time.

    Any advice?
     
  2. jodelli macrumors 65816

    jodelli

    Joined:
    Jan 6, 2008
    Location:
    Windsor, ON, Canada
    #2
    Why the second modem?
     
  3. nomar383 macrumors 65816

    nomar383

    Joined:
    Jan 29, 2008
    Location:
    Rexburg, ID
    #3
    I work for NETGEAR customer support. The first thing I would tell you is to reset the Linksys router to factory. The router should automatically assign valid IP addresses via DHCP. To configure wireless plug one of your macs directly into the router. Then, type 192.168.1.1 in your web browser. The default username and password should be something like admin/admin or admin/password. From there go to wireless settings and configure the wireless.

    Comcast assigns you what is called a WAN IP which you have no control over. That is assigned to the modem, not the router. The router then creates (on its own) Private IP addresses for each computer. If you reset the router to factory condition it should fix anything you have mistakenly done :)

    Try that

    EDIT: BTW I talk to Comcast Technicians several times a day and they are 100% morons. <I>Especially</I> with any macs around. Usually Comcast gives out our NETGEAR routers to their customers, which is why I deal with them.
     
  4. jodelli macrumors 65816

    jodelli

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    Jan 6, 2008
    Location:
    Windsor, ON, Canada
    #4
    Ditto. Plug the Macs directly into the router.
     
  5. jaygriffith thread starter macrumors newbie

    Joined:
    Jul 4, 2008
    #5
    Comcast and router

    Thanks to both of you for taking the time to reply.

    The current router is not wireless. I'm not sure if that matters since I connect everything via ethernet cable.

    But my prior router was also a wireless. I just didn't use that feature. But both computers were able to connect fine.

    If the non wireless router will work, then how do I go about resetting at factor settings?

    Thank you again.

    Happy 4th.
     
  6. nomar383 macrumors 65816

    nomar383

    Joined:
    Jan 29, 2008
    Location:
    Rexburg, ID
    #6
    Check out the linksys website, but I am pretty sure there should be a pinhole on the back that you use a paperclip to depress until the lights on the front begin to blink or turn off.
     
  7. agentphish macrumors 65816

    agentphish

    Joined:
    Sep 7, 2004
    #7
    Take that "phone modem" out of the loop and see what happens too.

    If Vonage isn't working, don't deal with that now. Get your computers working and then go from there.

    Resetting the router is definitely a great idea, and don't ever listen to a comcast tech when it comes to a Mac, and especially if it comes to a router, UNLESS they provided it because then they are required to support it...

    I've had Comcast techs tell me so many times that my router settings must be wrong...when really it was just them being morons and not knowing what's going on on their end. 95% of the time, they are useless.

    I've been using hubs/switches and routers since I was 12...That would be 15 years, I like to think I know what I'm doing at this point.
     
  8. myjay610 macrumors regular

    Joined:
    Jan 6, 2008
    #8
    Yeah, I agree with above as well. I'd just reset the router, and unplug the cable modem, wire everything correctly, then power the modem back on. Make sure your cat5 goes from the modem to the WAN port of the router too.

    Here's a page from vonage on the setup it sounds like you want...
    http://www.vonage.com/help.php?article=88&category=3&nav=3
     
  9. operator207 macrumors 6502

    Joined:
    Jul 24, 2007
    #9
    Actually, its assigned to the first mac address if the modem is a bridge, which most, if not all, are. They also have an IP address but is not for customer consumption. (my surf board had an IP of 192.168.1.100 or something like that, I could look at the gain on the line with that IP and its web interface) Comcast will assign the first mac address it see's after the modem/bridge which is either the router or the computer. Its the WAN IP your referring to. Then the router assigns DHCP after that to each device behind it that supports DHCP. I know this, because they only allowed 5 MAC addresses behind the modem unless you paid them $5 per MAC address a month more. If you had used up the 5 allocated to you, you could call them up, and remove old entries as they did understand people got new PCs or new routers from time to time.

    However, everything else you stated is correct, in regards to the support for Comcast, their lack of Mac support or any support that is not windows, the routers default config should work, etc.
     
  10. nomar383 macrumors 65816

    nomar383

    Joined:
    Jan 29, 2008
    Location:
    Rexburg, ID
    #10
    If his connection is Modem to router (the router not being controoled by the cable company) how would they know the MAC addresses the router controls? They MAY be able to detect the router's MAC address, but with NAT that should be the only address they could even attempt to detect. They can see the number of packets in/out, but not the specific computers they come from behind a router. Correct me if I am not understanding the problem
     
  11. operator207 macrumors 6502

    Joined:
    Jul 24, 2007
    #11
    No. The cc can only see what is directly behind the modem. Be it a computer or router or multiple computers on a switch or hub. That is was I was referring to. After so many mac addresses seen they block any new ones. Usually that number is 5. That is why mac spoofing on soho routers is a standard feature. Spoof/clone the mac address of your old computer, and the cc is none the wiser. Until they port scan your ip. ;)
     
  12. nomar383 macrumors 65816

    nomar383

    Joined:
    Jan 29, 2008
    Location:
    Rexburg, ID
    #12
    Gotcha, so if you have had multiple computers or routers over the course of a year hooked up to a modem, they could have seen 5 MAC adresses in that time. But, if you have only hooked up one router to the modem, the router could have hundreds of potential MAC address hooked up to it wirelessly and the modem would be none the wiser, correct?
     
  13. jaygriffith thread starter macrumors newbie

    Joined:
    Jul 4, 2008
    #13
    Thanks again

    A friend of mine got me up and running. He set it up and got it up and going.

    Thanks for taking the time to explain so well and help me out.

    jay
     
  14. operator207 macrumors 6502

    Joined:
    Jul 24, 2007
    #14
    Correct, assuming 5 is their limit, which was Comcast's back in the late 90's early 2000's when I had them. Also, if you spoofed/cloned your mac address over and over again, like I did with the 4-5 routers I blew through (bad wiring, literally blew one up once) they only thought you had one machine the entire time. Then whatever was behind that router, 1000 machines, or your computer and your network printer, was never really seen by Comcast, they could see your traffic, but as far as they were concerned, it was the MAC address they could see generating that traffic.
     

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