# Possible to split my cable modem between 2 computers? **URL:** \ **Category:** Factual Questions\ **Created:** [September 13, 2002, 4:24pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307 "2002-09-13T16:24:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![JimCarrey](https://avatars.discourse-cdn.com/v4/letter/j/5fc32e/32.png) [@JimCarrey](https://boards.straightdope.com/u/JimCarrey)\ **Post date:** [September 13, 2002, 4:24pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/1 "2002-09-13T16:24:01Z")
Is it possible for 2 roommates, each with his own computer, to split a cable modem so that one can be used for both computers at the same time? How? (Referring to Roadrunner service in NY, btw) ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 13, 2002, 4:35pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/2 "2002-09-13T16:35:53Z")
You need this product. I have one they work great for roadrunner in San Diego. [http://www.linksys.com/Products/product.asp?grid=23&prid=20](http://www.linksys.com/Products/product.asp?grid=23&prid=20) ---
**Author:** ![scout1222](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@scout1222](https://boards.straightdope.com/u/scout1222)\ **Post date:** [September 13, 2002, 4:44pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/3 "2002-09-13T16:44:30Z")
Wow! **gazpacho’s** right. I’ve got one of those, and it _does_ work great with Road Runner in San Diego! ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [September 13, 2002, 4:53pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/4 "2002-09-13T16:53:35Z")
I have the same unit in use with my DSL connection and it indeed does work well. It provides firewall protection as well as letting the two, or more, PCs share a connection. Of course you need a Network Interface Card (NIC) in each PC as well as a few Ethernet cables. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [September 13, 2002, 4:59pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/5 "2002-09-13T16:59:58Z")
I’m using a D-link router with my Linksys cable modem and doing fine so far. Much less expensive and I think Best Buy still has them on sale. ---
**Author:** ![whatami](https://avatars.discourse-cdn.com/v4/letter/w/85f322/32.png) [@whatami](https://boards.straightdope.com/u/whatami)\ **Post date:** [September 13, 2002, 5:03pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/6 "2002-09-13T17:03:13Z")
You can just get a router. I got the [BEFSR41](http://www.linksys.com/products/product.asp?grid=23&prid=20) and it works great. ---
**Author:** ![whatami](https://avatars.discourse-cdn.com/v4/letter/w/85f322/32.png) [@whatami](https://boards.straightdope.com/u/whatami)\ **Post date:** [September 13, 2002, 5:28pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/7 "2002-09-13T17:28:11Z")
oh sure, I know the answer and start my response, get called away for work(damn them) and you guys steal my thunder… ---
**Author:** ![LolaBaby](https://avatars.discourse-cdn.com/v4/letter/l/d2c977/32.png) [@LolaBaby](https://boards.straightdope.com/u/LolaBaby)\ **Post date:** [September 13, 2002, 5:32pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/8 "2002-09-13T17:32:47Z")
I have a Ethernet box thingy, but yes, it’s possible. Hawaii RoadRunner here. (See above posts for more coherent answers. 😃 ) ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [September 13, 2002, 6:14pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/9 "2002-09-13T18:14:04Z")
Please note, the text on the linksys site could be a bit confusing. If you get an Ethernet box thingy (thank you LolaBaby for the technical term ;)) that is _only_ a switch/hub but not also a router your cable company will know you have more than one computer connected and will charge you accordingly. The router part makes your home network appear to the outside world as a single computer. ---
**Author:** ![LolaBaby](https://avatars.discourse-cdn.com/v4/letter/l/d2c977/32.png) [@LolaBaby](https://boards.straightdope.com/u/LolaBaby)\ **Post date:** [September 13, 2002, 6:31pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/10 "2002-09-13T18:31:19Z")
:eek: Really, **Padeye**? I know we only have that Ethenet box thingy 😃 , but no router, and I’m _fairly_ sure we only pay for one. I have to go check, though. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [September 13, 2002, 6:39pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/11 "2002-09-13T18:39:16Z")
Well, Cox charges for additional IP addresses on home networks. Other ISPs may not but I’d be suprised. ---
**Author:** ![Bromley](https://avatars.discourse-cdn.com/v4/letter/b/4da419/32.png) [@Bromley](https://boards.straightdope.com/u/Bromley)\ **Post date:** [September 13, 2002, 8:00pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/12 "2002-09-13T20:00:17Z")
Yes, and you don’t need the high-tech ethernet box thingies. Just a spare network card in your gateway computer, a cross-over RJ45 and some proxy software. It works for me & my ISP (NTL UK), YMMV: [How to](http://www.networklab.co.uk/cmodem/convert.html) [WinGate lite proxy software](http://www.deerfield.com/products/wingate/home/) ---
**Author:** ![Iteki](https://avatars.discourse-cdn.com/v4/letter/i/eada6e/32.png) [@Iteki](https://boards.straightdope.com/u/Iteki)\ **Post date:** [September 13, 2002, 9:00pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/13 "2002-09-13T21:00:04Z")
Bromley has the right idea there. Two NICs on the main computer, one connected to the cable modem, one connected to the NIC on the secondary computer. The only drawback here is that gateway (main computer) has to be turned on and connected to the net for the other puter to use the net. Third suggestion is that if the pricing on the other hubs and routers is yucky, pay like 50 bucks for a 486 and use it as your router. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 13, 2002, 10:20pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/14 "2002-09-13T22:20:39Z")
I used to have an old computer act as the linksys box or (ethernet thingy as this thread calls them). However, it use more electricity than the linksys box and you still need a hub. The linksys boxes are about $80 so the $50 computer is not a lot cheaper. Another thing you get with the linksys box as has been pointed out here is a firewall. Using a computer you have to worry about security problems more than you do with the linksys box. ---
**Author:** ![DarkScooterPie](https://avatars.discourse-cdn.com/v4/letter/d/b3f665/32.png) [@DarkScooterPie](https://boards.straightdope.com/u/DarkScooterPie)\ **Post date:** [September 13, 2002, 10:56pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/15 "2002-09-13T22:56:42Z")
You want a router instead of a hub/switch even if you are not charged for a second IP address. The router will appear to be the computer to the outside world while your real PCs are hidden behind it. In simple language, the world will see the router’s address and not your PCs’. Thus if anyone tried to hack your address, they are trying to hack your dumb router while your PCs’ addresses are hidden. While NAT (address translation) is not perfect, it will keep out 98% of the hackers out there. Jim ---
**Author:** ![zen101](https://avatars.discourse-cdn.com/v4/letter/z/c68b51/32.png) [@zen101](https://boards.straightdope.com/u/zen101)\ **Post date:** [September 13, 2002, 11:07pm UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/16 "2002-09-13T23:07:19Z")
A Router as mentioned is a great tool, but many ISPs require you pay for an additional IP address. My own solution was simply to install another NIC card in my primary system and activate ICS (Internet Connection Sharing), then run my connection to one of my network hubs (living near Intel afforded me cheap access to their dumpsters, which used to be a great source of excellent secondhand equipment). Still I want to check out that Linksys product as i do not like leaving my system on 24/7. A third server computer can be used in a configuration similar to my existing one if you want to have a mail server. ---
**Author:** ![DarkScooterPie](https://avatars.discourse-cdn.com/v4/letter/d/b3f665/32.png) [@DarkScooterPie](https://boards.straightdope.com/u/DarkScooterPie)\ **Post date:** [September 14, 2002, 12:17am UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/17 "2002-09-14T00:17:10Z")
Zen101: Using a router is what will prevent the ISP knowing that you have multiple PCs hooked-up. If the ISP uses DHCP, your router will be assigned an IP address as if it was your PC. If the ISP uses static address, you can configure the router with the static address. The ISP will think the router is the PC they assigned the address to. Jim ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [September 14, 2002, 12:54am UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/18 "2002-09-14T00:54:40Z")
People, come on now. The Linksys BEFSR41, the nature of Network Address Translation, and so forth have been discussed at-length here by myself and others. The Linksys only uses 1 IP; it uses NAT to divide them amongst up to 254 computers. Cox, Roadrunner, Comcast, et al. can’t do a damn thing about it. It works, and it works damn well. Search this Forum for “Linksys”, and you will find multiple threads that go into much more detail. ---
**Author:** ![zen101](https://avatars.discourse-cdn.com/v4/letter/z/c68b51/32.png) [@zen101](https://boards.straightdope.com/u/zen101)\ **Post date:** [September 14, 2002, 1:02am UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/19 "2002-09-14T01:02:13Z")
My bad, I misued terminology. I’m apt to do that. I always call a network hub a ---
**Author:** ![zen101](https://avatars.discourse-cdn.com/v4/letter/z/c68b51/32.png) [@zen101](https://boards.straightdope.com/u/zen101)\ **Post date:** [September 14, 2002, 1:04am UTC](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307/20 "2002-09-14T01:04:40Z")
dammit, incomplete post. …router because I think of it as routing network traffic. [Next page](https://boards.straightdope.com/t/possible-to-split-my-cable-modem-between-2-computers/128307.md?page=2)