Browse Prior Art Database

Broadcast Duplicate Address Testing

IP.com Disclosure Number: IPCOM000121455D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 43K

Publishing Venue

IBM

Related People

Arroyo, KM: AUTHOR [+2]

Abstract

Token Ring adapters can insert into a network which includes source- routing bridges with an address that is a duplicate of some other adapter on the network, as long as the two adapters are on different rings. This can result in errors connecting and disconnecting links.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Broadcast Duplicate Address Testing

      Token Ring adapters can insert into a network which
includes source- routing bridges with an address that is a duplicate
of some other adapter on the network, as long as the two adapters are
on different rings.  This can result in errors connecting and
disconnecting links.

      The problem can be detected by using a feature of some network
management software, such as IBM's LAN Network Manager, but that
requires a management workstation, and only detects the problem after
the fact.  The problem can often exist undetected for long periods of
time until actual Logical Link problems occur, at which point the
underlying cause of a duplicate address may be very difficult to
diagnose.

      The NDIS-based 802.2 device driver for OS/2* implements a
solution to this problem on an individual workstation level.
Immediately after inserting into the ring, and before allowing any
user activity, the OS/2 802.2 interface device driver will perform a
broadcast duplicate address test to detect duplicate addresses
anywhere on the network. If a duplicate address is found, the device
driver will close the adapter and log an error message explaining the
problem.

      This broadcast duplicate address test will be optional through
configuration, allowing users who were intentionally using duplicate
addresses to continue to do so.

      The broadcast duplicate address test will use single-route
broadcast XID command frames sent...