I've shared comcast HSI personally and for some clients of mine...I
suggest installing 2 nic's in one box, and having that box serve the
internet to the rest.  I use ipkungfu to do this (an iptables script)
http://www.linuxkungfu.org/ipkungfu-0.2.1.tgz

Or you can use a broadband router

On Tue, 17 Dec 2002 17:11:08 -0600 (CST)
Dustin Decker <dustind@moon-lite.com> wrote:

> On Tue, 17 Dec 2002, Gene Dascher wrote:
> 
> > What do you mean "only connect the cable modem to the firewall or
> > you will have to work around that"?  What else would you connect the
> > firewall to? The only MAC address authentication that they do is on
> > the Cable modem itself, at least so far that I am aware.  I am using
> > an old 486 as my firewall with an old ISA NIC.  The PCI NIC that
> > they gave me is on another machine.
> 
> This is an issue with both Comcast _and_ RoadRunner.  Nearly all cable
> providers configure their head-end (for you dsl folks, think "dslam")
> to recognize a specific number of MAC addresses connected to the cable
> 
> modem.  If you cable directly from a pc to the cable modem, then they
> see one MAC.  If you cable the modem to a hub or switch, and then plug
> in multiple computers, then they see multiple MAC addresses.
> 
> This in and of itself is no biggy really - until you're ready to
> request an address from the DHCP server.  They generally configure to
> allow only one MAC address at a time to grab an IP.  Although you can
> turn off or disconnect the pc that last leased one, the MAC address is
> still cached on the cable modem.  The easiest way to clear it is to
> powercycle the modem.
> 
> I have found that RoadRunner is quite easy to deal with on this - I
> just gave 'em a call and asked that they open mine up to allow
> multiple MAC addresses... for my home PC, the wife, and that laptop I
> wander back and forth between work and home with.  (Whatever story you
> need to tell them to get however many IPs up and running.)
> 
> Hope this helps - Dustin
> 
> -- 
> *-----------------------------------*
> | Dustin Decker                     |
> | dustind@moon-lite.com      
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