[Arm-netbook] ZeroPhone

[Luke Kenneth Casson Leighton]

On Mon, Apr 17, 2017 at 4:23 PM, Adam Van Ymeren <adam.vany at gmail.com> wrote:
> Interesting.  Any chance you can link to some documentation about the network neighbourhood protocol?  Or outline what about it made it so resilient?  Thanks!

 the first thing is: it was documented as rfc1001 / rfc1002.which is
an extension of NETBEUI (a layer 2 protocol) on top of TCP/IP.  if
memory serves correctly this was done by IBM.

 SMB was dropped *on top* of NBT, as a registered service.  there are
actually several registered services, some equivalent to TCP and some
to UDP.

 one of the things that was missing from rfc1001 / 1002 was "please
give me a full list of participants in a particular group".  so
microsoft ended up adding an RPC function (on top of LANMAN, which was
on top of NamedPipes, which are on top of SMB which are on top of NBT
which are on top of TCP) whereby any participant in the network
neighbourhood can obtain a full list of participants in a group name
registration.  typically this would involve contacting the Primary
Domain Controller to ask for a list of members of a "workgroup".

 so that's some of the background.

 specific features which make the network neighbourhood robust:

 * the use of a central WINS server, similar to a DNS server.  this
allowed for cross-subnet / cross-network spanning *without* requiring
UDP broadcasting to be enabled across subnets (which many networks DID
enable... causing mayhem in the process.  the correct use of a WINS
server removed the need to screw with your network)

 * the "name conflict" concept.  if two parties try to register the
same name, they are REQUIRED to publish a "Name Conflict detected"
message, with associated user notification popups.

 * scopes.  this is equivalent to dns "zones" (and actually *uses* the
DNS "zone" field) and allows for isolation of networks of names even
on the same subnets.  unfortunately microsoft fucked up and FAILED to
respect scope.... rendering the feature totally useless.

lastly it's worth noting that the network neighbourhood is so
comprehensive and complex that *every* single organisation that has
ever attempted to implement it has taken at least THREE YEARS to get
their implementation correct and bug-free.

l.