How to connect to internet without router?

Howard Coles Jr. dhcolesj at gmail.com
Mon Jul 3 17:44:06 UTC 2006


On Monday 03 July 2006 12:14 pm, Dotan Cohen wrote:
> On Mon, 03 Jul 2006 12:44 -0400, Scott Kitterman <kubuntu at kitterman.com> 
wrote:
> > This isn't exactly an answer to your question, but it may be a solution
> > to your original problem...
> >
> > IIRC,   your setup is something like:
> >
> > pc --> router --> modem* --> internet
>
> yes
>
> > *I don't recall if you have DSL or cable, but I don't think it matters.
>
> cable
>
> > In most setups, the modem will use NAT (network address translation) and
> > DHCP to automatically assign a private IP address to whatever devices are
> > assigned to it.  Your router will also probably use NAT/DHCP for devices
> > connected to it.  So, from an address perspective the setup is:
> >
> > pc --> NAT --> NAT --> internet
> >
> > About the kindest thing you can say about NAT from a design perspective
> > is that it's  useful hack.  Earlier this year I resolved some long
> > standing packet loss problems I had be getting rid of this layered NAT
> > architecture and just having one level of NAT.
> >
> > What I was able to do is put my cable modem in bridge mode and assigned a
> > public IP address to my router.  Unless you have multiple public IP
> > accounts, you won't be able to do it this way.  What you would need to
> > try is setting your router up as a bridge so that the modem is the only
> > DHCP/NAT running.
> >
> > Consult your router documentation or tech support on how to do this.
>
> Even if the router has that ability, it's most likely handicapped. The
> router has two telephone jacks for VOIP, and they're disabled so I
> have another router for telephone (which itself has the ethernet port
> and USB disabled). They really discourage routers here, such that if
> you tell them in tech support that you have a router, most likely
> they'll tell you that they don't support routers and they won't help
> troubleshoot until the router is not part of system. (ie, modem and
> windows computer ONLY). There are a few techs that'll talk around the
> subject, but it's hit-or-miss and they certainly won't help with
> anything directly related to the router.
>
> In any case, is there no way for a Kubuntu machine to connect to the
> internet via a standard external modem, be it cable or [a]DSL? Even
> the ubuntu wiki is not helpful. How is [k]Ubuntu supposed to squash
> bug #1 if it can't connect to the internet?
>
> In a more productive tone, if anybody connects their Kubuntu machine
> directly to the modem, I'd love to hear from them. As soon as I've the
> necessary information I'll gladly update the docs myself.

If you are connecting up via Cable, the authentication should be contained in 
the modem.  All you have to do is set your Kubuntu box up for DHCP and boot 
up, or ifdown, connect cable, and ifup the nic.  

The question is with the delay, how do your internal boxes get their IP 
address / DNS name and Server IP addresses / router config?  Is it all 
static, or dhcp?  

I have two Linksys routers connected to my Cable modem.  One is my VOIP 
provider (two voice ports) and the other is my Wireless.  One of them 
performs the NAT function, and hands out DHCP addresses, the other is just a 
device on the net.  I figured out what DNS IP addresses to send to my 
internal boxes by setting the first router to DHCP and then checking what 
settings it had received.  If your DNS setup is hosed you'll have a hard time 
communicating to some sites.

-- 
See Ya'
Howard Coles Jr.
John 3:16!

http://risenbooks.com Christian bookstore




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