Enterasys Networks 9034313-07 Configuring Link Layer Discovery Protocol and LLDP-MED, Overview

Configuring Link Layer Discovery Protocol and LLDP-MED

Examples

This example shows how to clear all the Cisco DP parameters back to the default settings.

C3(rw)->clear ciscodp

This example shows how to clear the Cisco DP status on port ge.1.5.

C3(rw)->clear ciscodp port status ge.1.5

Configuring Link Layer Discovery Protocol and LLDP-MED

Overview

The Link Layer Discovery Protocol (LLPD) provides an industry standard, vendor‐neutral way to allow network devices to advertise their identities and capabilities on a local area network, and to discover that information about their neighbors.

LLDP‐MED is an enhancement to LLDP that provides the following benefits:

•Auto‐discovery of LAN policies, such as VLAN id, 802.1p priority, and DiffServ codepoint settings, leading to “plug‐and‐play” networking

•Device location and topology discovery, allowing creation of location databases and, in the case of VoIP, provision of E911 services

•Extended and automated power management of Power over Ethernet endpoints

•Inventory management, allowing network administrators to track their network devices and to determine their characteristics, such as manufacturer, software and hardware versions, and serial or asset numbers

The information sent by an LLDP‐enabled device is extracted and tabulated by its peers. The communication can be done when information changes or on a periodic basis. The information tabulated is aged to ensure that it is kept up to date. Ports can be configured to send this information, receive this information, or both send and receive.

Either LLDP or LLDP‐MED, but not both, can be used on an interface between two devices. A switch port uses LLDP‐MED when it detects that an LLDP‐MED‐capable device is connected to it.

LLDP information is contained within a Link Layer Discovery Protocol Data Unit (LLDPDU) sent in a single 802.3 Ethernet frame. The information fields in LLDPDU are a sequence of short, variable‐length, information elements known as TLVs — type, length, and value fields where:

•Type identifies what kind of information is being sent

•Length indicates the length of the information string in octets

•Value is the actual information that needs to be sent

The LLDP standard specifies that certain TLVs are mandatory in transmitted LLDPDUs, while others are optional. You can configure on a port‐specific basis which optional LLDP and LLDP‐ MED TLVs should be sent in LLDPDUs.

Purpose

To review and configure LLPD and LLPD‐MED.

SecureStack C3 Configuration Guide 6-13