Browse Prior Art Database

Potential Elimination of NetBIOS Broadcast Storms Caused by Group Name

IP.com Disclosure Number: IPCOM000116068D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 91K

Publishing Venue

IBM

Related People

Anand, VK: AUTHOR [+2]

Abstract

NetBIOS implemented using Transmission Control Protocol/Internet Protocol (TCP/IP) as the transport mechanism presents some additional difficulties not found in standard NetBIOS implementations using the IEEE 802.2 protocol as the transport mechanism. NetBIOS over TCP/IP is fully described in two internet Request For Comments (RFCs) documents numbered 1001 and 1002. This disclosure addresses the problem of sending a NetBIOS datagram to a NetBIOS Group Name. (A NetBIOS group name is a name that can be shared by many workstations. This differs from a NetBIOS unique name which can be owned by only one workstation.)

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Potential Elimination of NetBIOS Broadcast Storms Caused by Group Name

      NetBIOS implemented using Transmission Control
Protocol/Internet Protocol (TCP/IP) as the transport mechanism
presents some additional difficulties not found in standard NetBIOS
implementations using the IEEE 802.2 protocol as the transport
mechanism.  NetBIOS over TCP/IP is fully described in two internet
Request For Comments (RFCs) documents numbered 1001 and 1002.  This
disclosure addresses the problem of sending a NetBIOS datagram to a
NetBIOS Group Name.  (A NetBIOS group name is a name that can be
shared by many workstations.  This differs from a NetBIOS unique name
which can be owned by only one workstation.)

      First, let us review how a datagram is sent to a group name in
standard NetBIOS using 802.2 as the transport protocol.  A NetBIOS
application issues a NetBIOS Control Block (NCB) with command code
set to send datagram to the NetBIOS component.  The application
specifies the destination NetBIOS name as a group name.  The NetBIOS
component builds a send datagram NetBIOS packet and specifies the
destination network address as the NetBIOS Functional Address (IEEE
802.2 supports functional addresses).  The packet is sent by the
802.2 transport component.  The packet will be received by all
NetBIOS workstations which have added the NetBIOS functional address.

    The method used by standard NetBIOS will not work when TCP/IP is
the underlying transport.  The reason is that TCP/IP does not support
functional addresses.  The RFCs 1001/1002 state that when sending a
datagram, the NetBIOS component must first do name discovery on the
destination name.  This results in a name query packet being
broadcast to the network.  When name recognized response packets are
received, the response packet is checked to see if the responding
workstation has the name registered as a group name.  If so, the
datagram is being sent to a group name and must broadcast the
datagram to the network.  There is one tremendous problem with this
method for sending a datagram to a group name.  The problem is that a
network broadcast storm can be created by sending a name query packet
for a group name.  For example, suppose a network has 100 LAN
requesto...