Some parts of AT&T's cable networks are unfiltered at layer 2, so you can catch other's broadcasts (even the routers who run OSPF on a broadcast network in case you were interested). It definitly is a shared medium in my town.
-- RFC 1149 Compliant. Get in my head: http://sar.dynu.com ""Priscilla Oppenheimer"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > 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=38719&t=38705 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
