RE: Linux Network Security: POP
On Mon, 19 Mar 2001, Joris Lambrecht wrote:
> I asssumed cable modems were encrypting there communications with some
> simple built-in algorithm
It is my understanding that modern DOCSIS modems use encryption between
the cable modem and the cable head end. The motorola cybersufr brand has
been doing this forever as well. This prevents someone from using some
sort of cable analyser to sniff datagrams after they hit the wire..
I wouldn't count on the encryption being actually super secure, but it is
unlikely that someone is going to be sniffing packets by examining the
signals on the coax.
> as you should be, cable modems generally are equivilent to large
> unswitched lans, which means any bozo with a cable modem can set thier
> machine to primisquous mode and see every packet sent by any cable
> modem user. (at least for that segment)
This is certianly untrue for modern cable stuff. In general, the bandwidth
on the actual coax is far greater than 10mbit ethernet (coming out of the
modem), even if the modem wanted to it couldn't spew all packets onto the
local lan.
Jason
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