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BigIron RX Series Configuration Guide
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53-1002253-01
General operating principles
9
•
Can discover devices with misconfigured or unreachable IP addresses
General operating principles
LLDP use the services of the Data Link sublayers, Logical Link Control and Media Access Control, to
transmit and receive information to and from other
LLDP Agents
(protocol entities that implement
LLDP).
LLDP is a one-way protocol. An LLDP agent can transmit and receive information to and from
another LLDP agent located on an adjacent device, but it cannot solicit information from another
LLDP agent, nor can it acknowledge information received from another LLDP agent.
Operating modes
When LLDP is enabled on a global basis, by default, each port on the Brocade device will be
capable of transmitting and receiving LLDP packets. You can disable a port’s ability to transmit
and receive LLDP packets, or change the operating mode to one of the following:
•
Transmit LLDP information only
•
Receive LLDP information only
Transmit mode
An LLDP agent sends LLDP packets to adjacent LLDP-enabled devices. The LLDP packets contain
information about the transmitting device and port.
An LLDP agent initiates the transmission of LLDP packets whenever the transmit countdown timing
counter expires, or whenever LLDP information has changed. When a transmit cycle is initiated,
the LLDP manager extracts the MIB objects and formats this information into TLVs. The TLVs are
inserted into an LLDPDU, addressing parameters are prepended to the LLDPDU, and the
information is sent out LLDP-enabled ports to adjacent LLDP-enabled devices.
Receive mode
An LLDP agent receives LLDP packets from adjacent LLDP-enabled devices. The LLDP packets
contain information about the transmitting device and port.
When an LLDP agent receives LLDP packets, it checks to ensure that the LLDPDUs contain the
correct sequence of mandatory TLVs, then validates optional TLVs. If the LLDP agent detects any
errors in the LLDPDUs and TLVs, it drops them in software. TLVs that are not recognized but do not
contain basic formatting errors, are assumed to be valid and are assigned a temporary
identification index and stored for future possible alter retrieval by network management. All
validated TLVs are stored in the neighbor database.
LLDP packets
LLDP agents transmit information about a sending device or port in packets called LLDP Data Units
(LLDPDUs). All the LLDP information to be communicated by a device is contained within a single
1500 byte packet. A device receiving LLDP packets is not permitted to combine information from
multiple packets.
Summary of Contents for BigIron RX Series
Page 228: ...152 BigIron RX Series Configuration Guide 53 1002253 01 Enabling WAN PHY mode support 6 ...
Page 312: ...236 BigIron RX Series Configuration Guide 53 1002253 01 Displaying IP information 7 ...
Page 356: ...280 BigIron RX Series Configuration Guide 53 1002253 01 Resetting LLDP statistics 9 ...
Page 402: ...326 BigIron RX Series Configuration Guide 53 1002253 01 Transparent firewall mode 11 ...
Page 432: ...356 BigIron RX Series Configuration Guide 53 1002253 01 SuperSpan 12 ...
Page 500: ...424 BigIron RX Series Configuration Guide 53 1002253 01 MRP CLI example 14 ...
Page 591: ...BigIron RX Series Configuration Guide 515 53 1002253 01 Displaying traffic reduction 19 ...
Page 592: ...516 BigIron RX Series Configuration Guide 53 1002253 01 Displaying traffic reduction 19 ...
Page 598: ...522 BigIron RX Series Configuration Guide 53 1002253 01 Viewing Layer 2 ACLs 20 ...
Page 656: ...580 BigIron RX Series Configuration Guide 53 1002253 01 Trunk formation 22 ...
Page 754: ...678 BigIron RX Series Configuration Guide 53 1002253 01 Displaying RIP filters 24 ...
Page 814: ...738 BigIron RX Series Configuration Guide 53 1002253 01 Displaying OSPF information 25 ...
Page 980: ...904 BigIron RX Series Configuration Guide 53 1002253 01 Clearing IS IS information 28 ...
Page 1000: ...924 BigIron RX Series Configuration Guide 53 1002253 01 Using secure copy 30 ...
Page 1088: ...1012 BigIron RX Series Configuration Guide 53 1002253 01 IP source guard 35 ...
Page 1108: ...1032 BigIron RX Series Configuration Guide 53 1002253 01 Reading CDP packets 37 ...
Page 1126: ...1050 BigIron RX Series Configuration Guide 53 1002253 01 Clearing sFlow statistics 39 ...
Page 1324: ...1248 BigIron RX Series Configuration Guide 53 1002253 01 Displaying OSPFv3 information 48 ...
Page 1363: ...BigIron RX Series Configuration Guide 1287 53 1002253 01 Continuous System Monitor 51 ...
Page 1364: ...1288 BigIron RX Series Configuration Guide 53 1002253 01 Continuous System Monitor 51 ...
Page 1404: ...1328 BigIron RX Series Configuration Guide 53 1002253 01 Commands That Require a Reload D ...
Page 1458: ...1382 BigIron RX Series Configuration Guide 53 1002253 01 VSRP E ...