OPEN DOOR NETWORKS ANNOUNCES DOORSTOP

MACINTOSH-BASED FIREWALL ENHANCES SERVER SECURITY

ASHLAND, OR. -- August 7, 1998 -- Open Door Networks Inc. today announced
availability of a beta version of a major new Mac OS security product.
DoorStop (TM) is a software-based "firewall" product, letting server
administrators specify, on a service-by-service basis, a list of client IP
addresses that should be denied access to a particular service. DoorStop
enhances the security of Macintosh servers by providing an additional level
of protection, above and beyond those already built into the Mac OS and the
servers themselves.

"The Mac OS is already acknowledged as one of the most secure in the
world," said Alan Oppenheimer, president of Open Door Networks. "With
DoorStop we're just adding one more level of easy-to-use, powerful security
to that OS. DoorStop eliminates concerns about misconfiguration of servers
and helps administrators notice potential security holes and break in
attempts."

Unlike conventional, hardware-based firewalls, a copy of DoorStop is
installed on the server machines where its features are desired. By
distributing the firewall functionality down to the particular servers
being protected, DoorStop can provide additional levels of flexibility and
a significantly simplified user interface. Additionally, DoorStop can be
tailored for Macintosh-based servers in general, and for specific Macintosh
servers in particular (such as AppleShare IP, WebSTAR 3.0 and Open Door's
ShareWay IP product line).

DoorStop is especially critical when run with ShareWay IP. ShareWay IP
enables previously AppleTalk-only AFP (AppleTalk Filing Protocol) servers
to communicate over the Internet or an intranet. This increasingly
essential capability greatly expands the reach of AFP servers such as the
Mac's built-in personal file sharing. It also, however, exposes those
servers, for the first time, to access from beyond an organization's
AppleTalk network, requiring the additional security provided by DoorStop.

DoorStop provides machine-specific TCP (transmission control protocol)
connection filtering and logging, including:

- filtering by destination port number (specific service type)
- filtering by client IP address or address range
- filtering by server IP address on multihomed machines
- optional logging of both allowed and denied connection attempts.

DoorStop requires a PowerPC processor, Mac OS 8.1 and Open Transport 1.3 or
later, and is expected to ship by September. A beta version is available
immediately off the DoorStop Web site at http://www.opendoor.com/doorstop/
along with additional information on the product. Pricing of DoorStop has
not yet been determined.

Open Door Networks, Inc., a pioneer in the field of Internet tools for
Macintosh computers, was founded in January, 1995 by Alan Oppenheimer, an
11-year Apple veteran and co-creator of the AppleTalk network system. Open
Door's mission is to provide Macintosh users with Internet solutions that
are as easy-to-use and as powerful as the Macintosh itself. Open Door
Networks is located in Ashland, Oregon.