Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 120)

90 Multi-Service IronWare Switching Configuration Guide
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Configuration considerations
4
The TTL value is automatically computed based on the LLDP configuration settings. The TTL value
will appear similar to the following on the remote device, and in the CLI display output on the
Brocade device (show lldp local-info):
Time to live: 40 seconds
• If the TTL field has a value other than zero, the receiving LLDP agent is notified to completely
replace all information associated with the LLDP agent or port with the information in the
received LLDPDU.
• If the TTL field value is zero, the receiving LLDP agent is notified that all system information
associated with the LLDP agent or port is to be deleted. This TLV may be used, for example, to
signal that the sending port has initiated a port shutdown procedure.
Configuration considerations
• LLDP is supported on Ethernet interfaces only.
• If a port is 802.1X-enabled, the transmission and reception of LLDP packets will only take
place while the port is authorized.
• Cisco Discovery Protocol (CDP) and Foundry Discovery Protocol (FDP) run independently of
LLDP; therefore, these discovery protocols can run simultaneously on the same device.
• LLDP is supported on VPLS/VLL end-points and the behavior is the same as other interfaces.
• LLDP packets have the standard Multicast Destination MAC address and are sent with highest
priority (7).
• By default, the Brocade device limits the number of neighbors per port to four (valid range is 1-
64), and staggers the transmission of LLDP packets on different ports, in order to minimize any
high-usage spikes to the CPU.
• If the advertisements by the neighbor exceed the maximum value of the neighbor per port or if
it exceeds the maximum neighbors configured at the global level then the new advertisements
will be dropped.
• LLDP advertisements are limited to a single 1500 byte packet.
Using LLDP
LLDP is disabled by default on individual ports. To run LLDP, it must be enabled on a global basis
(on the entire device).
Enabling LLDP
To enable LLDP globally, enter the lldp run command at the Global CONFIG level of the CLI.
Brocade(config)# lldp run
Syntax: [no] lldp run
Changing the operating mode of a port
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. Each port can be configured for a different
operating mode on the Brocade device.