Chapter 67: LLDP and LLDP-MED
1050
Overview
Link Layer Discovery Protocol (LLDP) and Link Layer Discovery Protocol
for Media Endpoint Devices (LLDP-MED) allow Ethernet network devices,
such as switches and routers, to receive and transmit device-related
information to directly connected devices on the network that are also
using the protocols, and to store the information that is learned about other
devices. The data sent and received by LLDP and LLDP-MED are useful
for many reasons. The switch can discover other devices directly
connected to it. Neighboring devices can use LLDP to advertise some
parts of their Layer 2 configuration to each other, enabling some kinds of
misconfiguration to be more easily detected and corrected.
LLDP is a “one-hop” protocol; LLDP information can only be sent to and
received by devices that are directly connected to each other, or
connected via a hub or repeater. Devices that are directly connected to
each other are called neighbors. Advertised information is not forwarded
on to other devices on the network. LLDP is a one-way protocol. That is,
the information transmitted in LLDP advertisements flows in one direction
only, from one device to its neighbors, and the communication ends there.
Transmitted advertisements do not solicit responses, and received
advertisements do not solicit acknowledgements. LLDP cannot solicit any
information from other devices. LLDP operates over physical ports only.
For example, it can be configured on switch ports that belong to static port
trunks or LACP trunks, but not on the trunks themselves. In addition, LLDP
can be configured on switch ports that belong to VLANs, but not on the
VLANs themselves.
Each port can be configured to transmit local information, receive neighbor
information, or both. LLDP transmits information as packets called LLDP
Data Units (LLDPDUs). An LLDPDU consists of a set of Type-Length-
Value elements (TLV), each of which contains a particular type of
information about the device or port transmitting it.
A single LLDPDU contains multiple TLVs. TLVs are short information
elements that communicate complex data, such as variable length strings,
in a standardized format. Each TLV advertises a single type of
information, such as its device ID, type, or management addresses.
The TLVs are grouped as follows
“Mandatory LLDP TLVs” on page 1051
“Optional LLDP TLVs” on page 1051
“Optional LLDP-MED TLVs” on page 1053
Содержание AT-9000/12PoE
Страница 4: ......
Страница 28: ...Contents 28...
Страница 36: ...Tables 36...
Страница 42: ...42...
Страница 76: ...Chapter 2 Starting a Management Session 76...
Страница 100: ...Chapter 4 Basic Command Line Management Commands 100...
Страница 112: ...112...
Страница 130: ...Chapter 7 Basic Switch Management 130...
Страница 170: ...Chapter 8 Basic Switch Management Commands 170...
Страница 284: ...Chapter 12 Power Over Ethernet Commands 284...
Страница 298: ...Chapter 13 IPv4 and IPv6 Management Addresses 298...
Страница 322: ...Chapter 14 IPv4 and IPv6 Management Address Commands 322...
Страница 342: ...Chapter 16 SNTP Client Commands 342...
Страница 371: ...AT 9000 Switch Command Line User s Guide 371 awplus write Save the configuration...
Страница 388: ...Chapter 19 Enhanced Stacking 388...
Страница 406: ...Chapter 20 Enhanced Stacking Commands 406...
Страница 414: ...Chapter 21 Port Mirror 414...
Страница 422: ...Chapter 22 Port Mirror Commands 422...
Страница 432: ...Chapter 23 Internet Group Management Protocol IGMP Snooping 432...
Страница 452: ...Chapter 25 Multicast Commands 452...
Страница 454: ...454...
Страница 462: ...Chapter 26 File System 462...
Страница 488: ...Chapter 29 Boot Configuration File Commands 488...
Страница 500: ...Chapter 30 File Transfer 500...
Страница 508: ...Chapter 31 File Transfer Commands 508...
Страница 510: ...510...
Страница 528: ...Chapter 33 Event Log Commands 528...
Страница 536: ...Chapter 34 Syslog Client 536...
Страница 544: ...544...
Страница 554: ...Chapter 36 Static Port Trunks 554...
Страница 562: ...Chapter 37 Static Port Trunk Commands 562...
Страница 574: ...Chapter 38 Link Aggregation Control Protocol LACP 574...
Страница 588: ...Chapter 39 LACP Commands 588...
Страница 590: ...590...
Страница 610: ...Chapter 40 STP RSTP and MSTP Protocols 610...
Страница 690: ...Chapter 45 Multiple Spanning Tree Protocol MSTP 690...
Страница 716: ...716...
Страница 740: ...Chapter 47 Port based and Tagged VLANs 740...
Страница 760: ...Chapter 48 Port based and Tagged VLAN Commands 760...
Страница 778: ...Chapter 49 GARP VLAN Registration Protocol 778...
Страница 800: ...Chapter 50 GARP VLAN Registration Protocol Commands 800...
Страница 816: ...Chapter 51 MAC Address based VLANs 816...
Страница 830: ...Chapter 52 MAC Address based VLAN Commands 830...
Страница 850: ...Chapter 55 Voice VLAN Commands 850...
Страница 860: ...Chapter 56 VLAN Stacking 860 Section III File System...
Страница 866: ...Chapter 57 VLAN Stacking Commands 866 Section III File System...
Страница 868: ...868...
Страница 878: ...Chapter 58 MAC Address based Port Security 878...
Страница 892: ...Chapter 59 MAC Address based Port Security Commands 892...
Страница 918: ...Chapter 60 802 1x Port based Network Access Control 918...
Страница 960: ...Chapter 61 802 1x Port based Network Access Control Commands 960...
Страница 962: ...962...
Страница 974: ...Chapter 62 SNMPv1 and SNMPv2c 974...
Страница 1024: ...1024...
Страница 1036: ...Chapter 65 sFlow Agent 1036...
Страница 1140: ...Chapter 68 LLDP and LLDP MED Commands 1140...
Страница 1146: ...Chapter 69 Address Resolution Protocol ARP 1146...
Страница 1154: ...Chapter 70 Address Resolution Protocol ARP Commands 1154...
Страница 1170: ...Chapter 71 RMON 1170 awplus show rmon alarm Use the SHOW RMON ALARM command to verify the new alarm...
Страница 1228: ...Chapter 73 Advanced Access Control Lists ACLs 1228...
Страница 1288: ...1288...
Страница 1300: ...Chapter 76 Local Manager Accounts 1300...
Страница 1310: ...Chapter 77 Local Manager Account Commands 1310...
Страница 1316: ...Chapter 78 Telnet Server 1316...
Страница 1324: ...Chapter 80 Telnet Client 1324...
Страница 1328: ...Chapter 81 Telnet Client Commands 1328...
Страница 1340: ...Chapter 82 Secure Shell SSH Server 1340...
Страница 1350: ...Chapter 83 SSH Server Commands 1350...
Страница 1362: ...Chapter 85 Non secure HTTP Web Browser Server Commands 1362...
Страница 1406: ...Chapter 88 RADIUS and TACACS Clients 1406...
Страница 1446: ...Chapter System Monitoring Commands 1446...
Страница 1476: ...Appendix B Management Software Default Settings 1476...