Subject: Re: home networking security

From: Erik Guttman <[email-masked]>
Date: Wed, 3 May 2000 17:22:06 +0200 (MET DST)

At 10:57 PM 04/09/2000 -0400, Daniel Senie wrote:
>Before we continue down this path of figuring out security for accessing
>these various devices in the house, can we figure out where the
>addresses assigned to your water heater came from?

Daniel,

Thanks for your many comments on this thread. 

At 10:57 PM 04/09/2000 -0400, Daniel Senie wrote:
>Before we continue down this path of figuring out security for accessing
>these various devices in the house,

Just to be clear, protecting devices from being accessed is beyond the
scope of the working group.  Protecting the infrastructure by which 
devices are configured (or autoconfigure) is within scope.

> can we figure out where the addresses assigned to your water heater 
> came from?

Zeroconf protocols are independent.  That is, a host could have
a configured global address but still use ZC mechanisms for service
discovery, name resolution and multicast address allocation.

Further, even if addresses were assigned as link-local, it doesn't
mean that hosts remote to the link don't have access to it.  (The
link may be shared access media).

Finally, the zeroconf water heater may be given a routable address
by a hostile DHCP server as part of making accessible to an attack.

Erik