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2 Cable Modems

  1. Mar 30, 2004 #1
    I am wondering if it is possible to hook up 2 computers, with 2 separate cable modems, under the same broadband account.

    I already have broadband, and want to hook a second computer. I figured an easy way to do this, without running CAT 5 all over the place, and not hassling with wireless, is to buy a second modem, and call the cable company. I thought they would assign me a second IP address, I would pay an extra $5 a month, and be done.

    According to them, I would have to pay another full account for the second modem. They say if I want to use a second PC, I should buy a router, and that is when I would pay an extra $5 a month. I think this is ridiculous. If I bought a router, I would definitley not have to pay them extra per month.

    So...any ideas on how to utilize the second modem? I was under the impression that this is exactly how connection sharing would have been done a couple of years ago, before "home networking" became the rage. I would have gotten a second modem from the cable company, and paid the extra $5 for the second IP.

    I have to call back tomorrow when a "supervisor" is able to help me. I have a feeling that I will not get any better answer than what the "tech" gave me over the phone tonight. Anyone else's insight / experience with this matter would be appreciated.
  2. jcsd
  3. Mar 30, 2004 #2


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    If you connect two cable modems to your cable, you are getting twice the potential bandwidth. It is entirely reasonable for the company to charge you twice as much for twice the bandwidth.

    The best way to utilize a cable modem between two computers, if you are satisfied with splitting the cable bandwidth between both computers, is certainly just to use a router.

    If you don't tell the cable company you're using the router, they'll probably never notice, and you'll probably never have to pay the $5. I have heard that some cable companies routinely send packets out to screw up routers so they have to be reset every few days -- annoying, but not devastating.

    - Warren
  4. Mar 30, 2004 #3
    Thanks Warren. I didn't even consider that it would allow me to utilize twice the bandwidth. I just looked at it as a simple way to utilize the coax already available, instead of running CAT5 or going wireless.

    I will try to see what the cable company says tomorrow, and maybe I will then simply go with a wireless router.

    Am I correct in my belief that if this were a couple of years ago, and I wanted to have 2 PC's on the broadband connection, it would have required a second modem? I thought that was their solution before home networking became popular, and I thought it was a nominal charge back then too. I could be mistaken since it really wasn't an issue to me then, and so didn't really pay attention.
  5. Mar 30, 2004 #4


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    Networking has existed for many, many years. While you couldn't go to Best Buy and pick up a plug-n-play router, you could've used a cheapo linux box running NAT as many as eight or ten years ago. You could've run a proxy server even earlier than that.

    - Warren
  6. Apr 1, 2004 #5


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    Win 98 se came out with ICS (Internet Connection sharing) before 2000. I don't recall when exactly, but couldn't have been before '98. I used that to connect 2 computers to a dial up.

    I have been running 4 computers through a router to a cable modem for about 3 yrs now. No significant troubles.

    I have all of my systems in a single room simply to avoid the cabling issues. Since I hate passwords and active security measures I will not go wireless. I would not recommend wireless unless you are running WinXP and are ready to learn about and use every possible security measure. Wireless essentially opens your network to your whole neighborhood. You must take measures to protect it.
  7. Apr 1, 2004 #6
    Yes, I am aware that networking is nothing 'new', but it seems that with the recent explosion of off the shelf hardware, the cable company is pushing internet connection sharing.

    What I was wondering, if a couple of years ago, before you could go to Best Buy and pick up a router for under about fifty bucks, what would have been the cable companies solution for using the broadband connection between two PC's?

    I currently do share the cable modem between two PC's. I have a wireless router, and it works great. However, I want to share it now to a third, and I do not want to use wireless for the secutity concerns mentioned by Integral. I would want this PC to be more secure without the hassle of becoming a security expert.

    The room I will be putting the third PC already has a coax cable run to it for CATV. I have plaster walls and ceilings, and so I definitely do not want to start drilling holes to get across and down with CAT5. That is why I figured it would be best to pick up a second modem, and get on direct with this PC.

    I could have sworn that before the home networking explosion, the cable companies solution to ICS was a second modem and an extra $5-$10 per month. Like I stated earlier, I could be mistaken. I didn't really pay attention at the time. Does anyone else remember?
  8. Apr 1, 2004 #7


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    paul11273, you could try HomePNA technology:


    It basically uses your existing phone line to network computers
  9. Apr 1, 2004 #8

    They dont want you to share it. They would rather you buy multiple accounts. Up until a year ago, Comcast would yell at you if you had a router. Recently they just say its unsupported, and if you have any trouble, they make you take it off as they will say "its the router" instead of fixing hte problem.

    Anyway, as for security risks, THERE ARE NONE. 128-bit encryption takes way, way way too long to break, years even. If youre really scared that someone will latch onto your internet and use it (as unless you have stuff unsecurly shared which is a TERRIBLE idea in itself) all they can do is go to websites. But as long as you have 128 bit encryption they will NOT be able to crack it. If youre very paranoid you can just change the key every month.
  10. Apr 9, 2004 #9
    Aye, definitely do not tell the company if you hook up a 2nd computer on the router. That's the easiest way to do it. At my old house, I had 2 cable modems, and was paying 2 service fees. This was because I was also using my parents cable modem, because they never used it.

    Anyway, what is the security problem with wireless? My Link-Sys wireless router has a MAC address filter, and so only computers that I have approved their MAC address can even get on the network. Also, all my computers have firewalls. Is there any security issue beyond this?
  11. Apr 9, 2004 #10
    Don't worry about wireless risks. By doing two really simple steps while getting things up and running you'll make the network inpenetrable.

    A- set up the MAC address filter: this only allows your computers to connect in the first place. (it also requires someone with quite a bit of technical saavy to get around)

    B- use the 128-bit encryption... its basically unbreakable.. unless someone just gets really lucky

    Finally, if you're really paranoid: enable the routers logs (this way, if they want to clear themselves from the log, they also have to break your routers admin username and password)

    I wouldnt recommend it for the CIA.. but chances are you dont have classified documents that national security depends on.. and chances are your neighbours arent experts who want to go through a ton of trouble to see your files or steal some bandwidth.

    (just of note is that your network is much more exposed simply by being connected to the internet)
  12. Apr 10, 2004 #11
    Powerline Ethernet Bridges

    You can hook up a home network through the existing electrical wires in your home. The limiting condition with Powerline Ethernet Bridges is that they cannot be plugged into the AC outlet through a power-conditioning device. Other than that, you're good to go if you already have AC wires and outlets in the house.
  13. Apr 12, 2004 #12
    Just to let you know: I've heard about a method of obtaining double the bandwidth by having 2 Cable modems, 2 accounts, yet just 1 computer.
    Each NIC/Network Card can have it's own IP address, so if you use WIndows XP to bridge the connections between the two cable modems you might get double the bandwidth. I know there's also a device that does combine 2 accounts/IPs and cable modems to utilizine the full bandwidth.
    My friend had this installed a while ago before high speed companies were capping upload speeds to usually 15 kps. Since he was close to a node he was also recieving near T1 speeds for only 100/month. lol
    Definitley an interesting trick and can be helpful if you're downloading large files all the time like .ISO's from the Redhat servers. heh
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