[Charlug] Question about cable modem and dhcp

[Jared Watkins]

It sounds like you are trying to use both the usb and the network port from
the cable modem at the same time?  That's a no no... =]  Pick one.. I'd
suggest the network port and put a firewall in front of it to maintain a
steady connection or use your linux box as the firewall/router.

J



On 12/22/08 11:09 AM, "Kevin" <KSISSON at carolina.rr.com> wrote:

> Hi all,
> 
>     Several months ago I signed up for TW RoadRunner broadband cable
> service. The  service is pretty good (moved from dial-up), but I have
> noticed something that seems to be happening a little more frequently
> lately. I apparently loose the connection to the Internet, at apparently
> random intervals. I will notice that a site is not responding, or that a
> new site can't be found. When I check 'route' it hangs, instead of
> giving me back the normal listing with 'default' being the cable modem.
> Since I'm new to using dhcp, I don't know if the problem is on my end or
> RR's end.
> 
> The cable modem is an Ambit model (suppled by TW). I'm using a USB 2.0
> interface. I also have a small local ethernet system- standard Linksys
> card to hub (usually only the computer with the cable modem is running
> so the hub is not active). udev finds the cable modem when I boot up,
> assigns it to eth1, and 'dhcpcd -d -t 30 eth1' is run by the inet
> script. I wrote a bash script that will bring the modem interface up and
> down (for extra security, when I finish running a browser, the script
> brings the interface down, and back up when I start the browser). The
> script just does 'ifconfig eth1 down' or 'ifconfig eth1 up' and restarts
> inet1. Both times 'route' is executed to make sure the commands have
> gone through. When I lose the Internet connection, I run the script from
> a terminal window to reset everything. I'm not getting any error
> messages from the usb interface.
> 
> My problem/question is that I don't know exactly what is happening. I
> can go for days with losing the Internet (I'm on a total of several
> hours a day), or this can happen once or several times a day. I tried
> lengthening the dhcpcd timeout to 45 seconds, but so far that does not
> seem to have had any effect. Has anybody seem a similar problem, or can
> anybody point me in a direction to try to find the cause? The dhcp log
> doesn't tell me much. Thanks,
> 
>         Kevin
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