3com Corporation

Andrew Peter White

David E Bill

David Kirby

Christopher Robert Linzell

Simon Peter Valentine

Andrew M Davy

Stephen N Crocombe

Robert Allsworth

Peter Wai Lam

Christopher J Buse

A network management apparatus and method for determining the topology of a networkis described. The present invention uses data relating to discovered devices on the networktypically network management address table data, to build a network tree. Due to the presence of unsupported or unmanaged connecting network devices, some branches of the resulting tree may not be resolved. In order to address this, for each unresolved branch of the network tree, the present invention attempts to determine the type of each of the discovered network devices on the branch, and if the type of every discovered network device on the branch is determined to be an endstation type, the present invention determines that an undiscovered connecting device is present on the branch.

Method and apparatus for determining unmanaged network devices in the topology of a network

A device is discovered on a network by means of a discovery protocol operated by a proxy and a protocol address for the device is obtained if required by the proxy, which requests a protocol address in accordance with a dynamic host communication protocol, then in the absence of response to that request attempts automatic private addressing and finally if necessary allows manual entry of a protocol address for the device.

Allocation of IP address by proxy to device in a local area network

A network device which is for use in an Ethernet packet-based communication system has at least one port which is capable of auto-negotiation to select between half duplex and full duplex working on a link to which the port is connected. The device includes means for monitoring the existence of late collisions between packets on said link, means for monitoring the existence of packet fragments on the link, and monitoring means for detecting and correcting for a duplex mismatch on the link partner. This monitoring means is operative to determine whether there are any late collisions and in the absence of a detection of fragments to configure the port from a half duplex mode to a full duplex mode. The monitoring means is also operative to detect the presence of fragments when the port is in full duplex mode and thereby to provide an indication that a rule relating to network size is infringed.

Network device including automatic detection of duplex mismatch

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St. Albans, United Kingdom

Andrew Peter White