[Charlug] Question about cable modem and dhcp

[Kevin]

Jared Watkins wrote:
> 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
>
>
>
>   

Nope, sorry, I guess I wasn't clear. I meant to say that I have a 
network cable in the computer, but that it is being used for the 
network, not the cable modem. The only connection between the modem and 
the computer is through the usb cable. The RJ- connector on the modem is 
not being used. I'm using an iptables script as my firewall. Plus, the 
connection isbeing lost while I'm on the internet; shouldn't that be 
maintaining the connection?



> 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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