Understanding 802.1X And Lldp And Lldp-Med On Ex Series Switches - Juniper JUNOS OS 10.3 - SOFTWARE Manual

Complete Software Guide for Junos

Understanding 802.1X and LLDP and LLDP-MED on EX Series Switches

2540
®
OS for EX Series Ethernet Switches, Release 10.3
Juniper Networks EX Series Ethernet Switches use Link Layer Discovery Protocol (LLDP)
and Link Layer Discovery Protocol–Media Endpoint Discovery (LLDP-MED) to learn and
distribute device information on network links. The information allows the switch to
quickly identify a variety of devices, resulting in a LAN that interoperates smoothly and
efficiently.
LLDP-capable devices transmit information in type, length, and value (TLV) messages
to neighbor devices. Device information can include specifics, such as chassis and port
identification and system name and system capabilities. The TLVs leverage this
information from parameters that have already been configured in the Juniper Networks
Junos operating system (Junos OS).
LLDP-MED goes one step further, exchanging IP-telephony messages between the switch
and the IP telephone. These TLV messages provide detailed information on PoE policy.
The PoE Management TLVs let the switch ports advertise the power level and power
priority needed.
The switch also uses these protocols to ensure that voice traffic gets tagged and prioritized
with the correct values at the source itself. For example, 802.1p CoS and 802.1Q tag
information can be sent to the IP telephone.
EX Series switches support the following basic TLVs:
Chassis Identifier —The MAC address associated with the local system.
—The port identification for the specified port in the local system.
Port identifier
—The user-configured port description. The port description can be a
Port Description
maximum of 256 characters.
—The user-configured name of the local system. The system name can
System Name
be a maximum of 256 characters.
System Description —The system description containing information about the software
and current image running on the system. This information is not configurable, but
taken from the software.
—The primary function performed by the system. The capabilities
System Capabilities
that system supports; for example, bridge or router. This information is not configurable,
but based on the model of the product.
—The IP management address of the local system.
Management Address
EX Series switches support the following 802.3 TLVs:
—A TLV that advertises MDI power support, PSE power pair, and power
Power via MDI
class information.
MAC/PHY Configuration Status
interface, such as autonegotiation status and support and MAU type. The information
is not configurable, but based on the physical interface structure.
—A TLV that advertises information about the physical
Copyright © 2010, Juniper Networks, Inc.