At 02:56 PM 3/18/02, sam sneed wrote: >I just changed services from DSL to cable modem. I have heard from people, >including verizon, that cable is not as secure as DSL becuase it is over a >shared medium. I connected to my cable modem and fired up my packet sniffer. >I did not see anyone elses traffic on the line so i am assuming the bandwith >is shared( a known fact about cable access) but is somehow filtered at the >cable modem(bridge).
Presumably, you are using an Ethernet packet sniffer? The shared medium is on the cable modem side and is RF, not Ethernet. So, you're not going to see your neighbor doing e-mail or surfing the Web or whatever with your Ethernet sniffer. The traffic traverses the shared coax cable and probably hits a hybrid fiber coax (HFC) node at some point and goes over fiber to the head-end where it gets converted to Ethernet or whatever and shipped off to the destination. Your sniffer won't see this. On the other hand, you may see your neighbors' broadcasts, depending on the architecture of the cable provider's network. If it's a Layer 2 architecture without filtering, you may see broadcasts. There are stories about people using the Windows network neighborhood and seeing neighbor's computers and printers. I think most providers have cleaned this up though. That's a way over-simplified answer, but a couple pieces of the puzzle. Hopefully someone else will answer too. More info here too: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/cable.htm Priscilla >Does anyone know if this assumption is true and the >inside details of the how data is transmitted over the cable network? A link >to a whitepaer would be great. > >thanks ________________________ Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38716&t=38705 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
