US 6,611,525 B1 · Apparatus for and method of learning MAC addresses in a LAN emulation network

Abstract

An apparatus for and a method of learning MAC addresses in a Local Area Network (LAN) Emulation (LANE) network implemented over an Asynchronous Transfer Mode (ATM) network. The LEC or LES is adapted to detect when the ATM address associated with a MAC address is no longer valid. Once an invalid ATM address is detected the existing entry can be updated or deleted. A LEC_ID table holding LEC_ID to ATM address bindings is created. Each frame received by the LEC is sniffed in order to find mismatches between the ATM address and the LEC_ID. Optionally, an LE_ARP request message can be forwarded to the LES for learning the new binding. If the MAC address is not found in the LE_ARP table, an entry can be created and added to the table. In another embodiment, the LES is adapted to detect when the MAC to ATM address binding stored in the internal LE_ARP cache is no longer valid. The LE_ARP table is populated by examining LE_ARP request and response sent and received by the LEC. Upon detection of a mismatch in LEC_ID, the LES can delete or update the entry. The LES generates and sends a LE_NARP or targetless LE_ARP request message which finctions to notify the LEC in the ELAN of a changed MAC to ATM address binding.

Claims23

Dependent claims

A method of learning Media Access Control (MAC) addresses of stations connected to a LAN Emulation (LE) network, for use in a LAN Emulation Client (LEC) having an LE_ARP table and configured for use in an Asynchronous Traner Mode (ATM network implementing LE, said LE including a Broadcast and Unknown Server (BUS) entity, said method comprising the steps of;

creating a LEC_ID table in said LEC and storing LEC_ID to ATM address bindings therein extracted from control messages transmitted between LE entities;
sniffing messages originated by said stations forwarded by said BUS entity within said LE and received by said LEC;
determining a first LEC_ID from said LEC_ID table corresponding to a MAC source address of a station extracted from said received message;
comparing said first LEC_ID with a second LEC_ID extracted from said received message;
and
if said LEC_ID and said second LEC_ID do not match, performing an action in response thereto.

3 more elements

A method of learning Media Access Control (MAC) addresses of stations connected to a LAN Emulation (LE) network, for use in a LAN Emulation Server (LES) having an LE_ARP table and configured for use in an Asynchronous Transfer Mode (ATM) network implementing (LE), said LE including a Broadcast and Unknown Server (BUS) entity, said method comprising the steps of:

establishing a connection between said LES and said BUS entity, said connection for listening to traffic communicated thereover;
creating a LEC_ID table in said LES and storing LEC_ID to ATM address bindings therein extracted from control messages transmitted between LE entities;
establishing an LE_ARP table in said LES for storing station MAC address to ATM, address bindings;
sniffing messages originated by said stations forwarded by said BUS entity within said LE and received by said LES over said connection;
determining a first LEC_ID retrieved from said LEC_ID table corresponding to a MAC source address of a station extracted from said received message;
comparing said first LEC_ID with a second LEC_ID extracted from said received message;
and
if said first LEC_ID and said second LEC_ID do not match:
deleting the MAC address entry from said LE_ARP table;
notifying all LECs that the current MAC/ATM address binding is no longer valid.

7 more elements

Dependencies are inferred from the claim text.

Apparatus for and method of learning MAC addresses in a LAN emulation network

Life of this patent

Apparatus for and method of learning MAC addresses in a LAN emulation network

Life of this patent

Abstract

Claims23