Link Layer Discovery Protocol (LLDP) - Extreme Networks

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Organizationally-Specific TLVs Extreme Networks implementation of organizationallyspecific TLVs represent a commitment to fully enabling the network for converged applications and provide level of functionality beyond that of most equipment vendors. Organizationally-specific TLV extensions simplify the integration of multi-vendor access networks by assisting in the detection and configuration of IEEE 802.1 and IEEE 802.3 information. Additionally, standards organizations as well as vendors such as Extreme Networks will help to drive new functionality in LLDP extensions. New standards, such as LLDP-Media Endpoint Discovery (MED), will provide extensibility to fully standardized solutions to other reasonably predictable needs in this area, as well as allowing for vendor-specific extensions. 802.1 Extensions IEEE 802.1 extensions deal primarily with describing VLAN attributes. They will also be supported in the first release of LLDP support on Extreme Networks switches. Supported 802.1 extensions are the TLVs shown in Table 2. TLV Port VLAN ID Port & Protocol VLAN ID VLAN Name Protocol Identity 802.3 Extensions The IEEE 802.3 TLV extensions describe various attributes associates with the operation of an 802.3 LAN interface. The defined TLVs supported in the first implementation of LLDP are shown in Table 3. TLV MAC/PHY Configuration and Status Power-via-MDI Link Aggregation Maximum Frame Size DESCRIPTION Identifies the VLAN identifier associated with an untagged VLAN. Only one Port VLAN ID can exist in an LLDP PDU. Allows the port to advertise if it supports port/protocol based VLANs, and there associated VLAN ID. Allows a device to advertise the textual name of any VLAN with which it is configured. Provides the protocols that are accessible through the LLDP port. Table 2: LLDP 802.1 Extensions DESCRIPTION Determines more about the auto negotiation settings of the port, as well as the type of physical interface used. Advertises the power-via-MDI implementations supported by the port. Power Information allows for improved power management for endpoints utilizing IEEE 802.3af Power over Ethernet (PoE). Allows the port to send information about its configured link aggregation (whether the link is capable of being aggregated, whether it is currently in an aggregation and if in an ag-gregation, the port of the aggregation). Reports the maximum supported frame size for the port. Table 3: LLDP 802.3 Extensions LLDP-MED Extreme Networks Technical Brief LLDP-MED is a new set of standards enhancing the basic LLDP protocol, which applies to increased discovery of endpoint devices. In the future, Extreme Networks will implement many of the new LLDP-MED standards under development by the Telecommunications Industry Association (TIA). Management Components EPICenter Management LLDP provides detailed Layer 2 network information for connected access devices, exposing the entire LAN to the EPICenter management system. Layer 2 discovery drills down to the port that access devices are connected to and gives a complete understanding of connectivity and device properties. This granularity of detail is necessary to configure and maintain end-to-end networks from a network management system—“End-to-end,” meaning that network administrators should not have to manually audit a network to discover third-party vendor devices. Instead, LLDP allows for centralized management and automated discovery of all wired and wireless devices. This is achieved through flexible management views, with options that can be selected per device, user, action, time or location. Using LLDP in Extreme Networks devices, EPICenter manager is able to build a complete topology of the network and make automation a reality. Because LLDP messages are stored in the MIB of an Extreme Networks switch, EPICenter is able to obtain complete access to the information through SNMP advertisements. Having this control and information availability through EPICenter allows centralized access to accurate and timely network data, enabling simplified device management and troubleshooting. For example, it becomes possible for EPICenter management to discover configuration inconsistencies or malfunctions that can result in impaired communication at higher layers. Most importantly, EPICenter can obtain this information from all network devices, not just Extreme Networks devices. Command Line Interface (CLI) CLI is an optional method of configuration for LLDP. CLI can send configuration information per port to Extreme Networks switches via SNMP. CLI can also be used to maintain a list of LLDP enabled ports and the port mode (i.e. transmit only, receive only or transmit and receive). © 2006 Extreme Networks, Inc. All rights reserved. Link Layer Discovery Protocol—Page 4
Applications Diagnostics/Troubleshooting LLDP is a natural diagnostic tool because of its inherent ability to discover and maintain accurate and up-to-date network topologies. The TLV information exposes network mapping, inventory data and network troubleshooting information that may otherwise be unavailable. Network administrators can use this information to identify outdated hardware and software, speed and duplex mismatches and improperly configured devices. For example, using TTL values, LLDP can be used to locate ports that are no longer sending LLDP advertisements to determine endpoint devices that have gone out of service. Voice VoIP continues to demand availability standards and advanced functionality from data networks that will help put it on par with TDM systems. LLDP takes another step forward in achieving this goal by facilitating multi-vendor IP Telephony networks and enabling these networks to achieve dial-tone reliability. VoIP networks have been relatively slow to adopt voice-class features and have lacked complete integration with existing network management systems. IP telephones typically lack support of management protocols such as SNMP, prohibiting NMS systems from a complete network view. LLDP now brings discovery of VoIP topology information to Extreme Networks Management System. LLDP allows an IP phone to be dynamically and fully recognized by an Extreme Networks device. The Extreme Networks device is then able to adapt to the network according to the needs of the IP telephone and MIB information becomes accessible to EPICenter. Extreme Networks acts as an industry innovator by incorporating early-standards LLDP-MED functions and by making significant headway in building Plug-and-Play IP Telephony networks. Extreme Networks LLDP Implementation vs. Other Discovery Protocols Many network equipment vendors have developed discovery protocols to operate in homogeneous networks comprised of their own equipment. Cisco Systems has Cisco Discovery www.extremenetworks.com email: com info@extremenetworks. Corporate and North America Extreme Networks, Inc. 3585 Monroe Street Santa Clara, CA 95051 USA Phone +1 408 579 2800 Extreme Networks Technical Brief Protocol (CDP); Enterasys Networks, Cabletron Discovery Protocol (CDP); and Nortel Networks, Nortel Discovery Protocol (NDP). However, many network architects building out enterprise and carrier VoIP networks would like a standard means of discovery allowing them to mix best-of-breed equipment from multiple vendors. Most network designs are moving to a best-of-breed strategy where individual components in the network are chosen for their unique ability to handle an application. A standardsbased discovery protocol readies a network for convergence applications without major dependencies concerning the manufacturer of network equipment. See Figure 4 for a comparison between discovery protocols. Industry Standards Based Multi-Vendor Network Support Chassis & Port ID Port Description System Name System Description System Capabilities Management Address VLAN ID Voice VLANs Network Policy Auto Negotiation Requirements Power Information (PoE Capable) Frame Size Requirements Location Advertisements (E911 capable) Europe, Middle East, Africa and South America Phone +31 30 800 5100 Asia Pacific Phone +852 2517 1123 Y N N N Y N N N Y Y Y Y Y Y Y Y Y Y Y Y Y Y N N Y Y N N Y Y Y Y Y Y N N Y N N N Y N N N Y N N N Y Y N N Y N N N Y Y N N © 2006 Extreme Networks, Inc. All rights reserved. Extreme Networks, the Extreme Networks Logo, BlackDiamond and EPICenter, are either registered trademarks or trademarks of Extreme Networks, Inc. in the United States and/or other countries. Specifications are subject to change without notice. Japan Phone +81 3 5842 4011 1061_01 11/06 Link Layer Discovery Protocol Technology Brief LLDP-MED Cisco CDP Nortel NDP Figure 4: Competitive Discovery Methods Enterasys CDP
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Link Layer Discovery Protocol (LLDP) - Extreme Networks

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