On Thursday 11 May 2006 22:18, Grant <[EMAIL PROTECTED]> wrote
about 'Re: [gentoo-user] Gentoo ADSL wireless router (3 questions)':
> > > I'm completely sure it's just a DSL modem.
> > If that's all you have to do, it's definitely a "router".
>
> Weird.
Yeah, especially since the /same/ type of blackbox (no auth, just
cable<->ethernet translation) for cable service is called a "cable modem",
at least in my circles. *boggle* </snip>
DSL and cable modems are different. DSL uses PPPoE. A cable modem does not.
DSL requires you to enter a username/password to authenticate then it assigns an IP via DHCP (I've had DSL a few years in the past, that is the extent of my knowledge of how their system works).
A cable modem is like most any other network device: It listens for DHCP broadcast and picks up an IP for itself, and passes through DHCP broadcasts/acknowledgements to/from the device connected to it (it is more a bridge than a modem). As for authentication: most (re: nearly all) cable modem networks (at least DOCSIS compliant) use the MAC address of the cable modem to authenticate; however, some CTMS's (the server for the cable modems) have no authentication at all: you plug in the modem, it pulls an IP, then you're able to pull an external IP (nearly all IPs assigned through cable modems are DHCP; however, sometimes the network will be setup to assign private IPs w/ NAT enabled, but this is usually only when they run out of available public IPs/running a "special" system). But if the server admins are smart, they lock down the system by requiring MAC address-based authentication.
And yes, I am a cable modem tech support representative.
- Mark Shields
