🚀 go-pugleaf

In article <39AF0CDD.424A@pacbell.net>, oertell@pacbell.net wrote:

> > I heard a commercial the other day for DSL that compared cable service to
> > dsl, and claimed that dsl service was more secure than that of cable
> > service.  I disagree with that claim and I think any knowledgable user would
> > disagree.  No internet connection is that secure, just ask any company who
> > has had their firewall hacked.
> > 
>    I have to disagree with this.  As I understand cable modems, my local
> node is nothing more than a local ethernet LAN.  The box my cable
> connects to and routes my packets to the Internet is directly analogous
> to a bridge or router. If my packet is intended for another computer on
> my local node, the bridge doesn't route my packet out to the Internet. 
> (I realize this isn't the way most people use their computer, but the
> analogy holds).

You understand wrong.

The Motorola "Wave" modem that ATT@Home uses here in Seattle* encrypts
all data between it and the head-end box. I assume that DOCSIS modems
do likewise. Further, the modem sends and receives on different
frequencies - only the head-end box "listens" to the frequency sent
by the cable modem.

Even if one was able to "hack" a cable modem of this type into
promiscuous mode, you *still* wouldn't be able to "sniff" packets,
as they would all be encrypted. There is _no_ provision for direct
modem-to-modem communication in such a system. You basically have
no more access to your next-door neighbor's machine than you do
to someone's on the other side of the world. All communication
is through the head-end box, regardless of destination.

For the vast majority of cable modem systems, your "network 
neighborhood" is NOT a LAN in any meaningful way, other than
physically sharing a wire. Broadcast packets, etc. do NOT go
to other cable modems in the area. An analogy to a VPN between
you and the head-end box is a lot closer than the LAN model.

The "DSL is more secure" claim is just more F.U.D. against cable,
IMHO. Looks like it's fooling some people, just as the "sharing"
issue has.

P.S. Referring to a network neighborhood (all boxes which share
a cable and a single head-end box) as a "local node" is exceedingly
confusing terminology.

* I see that this is also posted to some Dallas - Fort Worth groups -
I have no idea what the cable system is like down there...

-- 
Jim Glidewell
My opinions only