Displaying Lldp Information For A Port - HP 1920 Gigabit Ethernet Switch Series User Manual

Item
TTL Multiplier
Trap Interval
Reinit Delay
Tx Delay
Tx Interval

Displaying LLDP information for a port

1. From the navigation tree, select Network > LLDP.
By default, the Port Setup tab is displayed.
2. On the port list, click a port name to display its LLDP information at the lower half of the page.
Description
Set the TTL multiplier.
The TTL TLV carried in an LLDPDU determines how long the device information
carried in the LLDPDU can be saved on a recipient device. You can configure
the TTL of locally sent LLDPDUs to determine how long information about the
local device can be saved on a neighbor device by setting the TTL multiplier.
The TTL is expressed as TTL multiplier × LLDP frame transmission interval.
When you configure the TTL multiplier, follow these guidelines:
•
If the product of the TTL multiplier and the LLDP frame transmission interval
is greater than 65535, the TTL carried in transmitted LLDP frames takes
65535 seconds.
•
Because the maximum TTL allowed by CDP is 255 seconds, you must make
sure the product of the TTL multiplier and the LLDP frame transmission
interval is less than 255 seconds for CDP-compatible LLDP to work correctly
with Cisco IP phones.
Set the minimum interval for sending traps.
With the LLDP trapping function enabled on a port, traps are sent out of the
port to advertise the topology changes detected over the trap interval to
neighbors. By tuning this interval, you can prevent excessive traps from being
sent when topology is instable.
Set initialization delay for LLDP-enabled ports.
Each time the LLDP operating mode of a port changes, its LLDP protocol state
machine reinitializes. A configurable reinitialization delay prevents frequent
initializations caused by frequent changes to the operating mode. If you
configure the reinitialization delay, a port must wait the specified amount of
time to initialize LLDP after the LLDP operating mode changes.
Set LLDP frame transmission delay.
With LLDP enabled, a port advertises LLDP frames to its neighbors both
periodically and when the local configuration changes. To avoid excessive
number of LLDP frames caused by frequent local configuration changes, an
LLDP frame transmission delay is introduced. After sending an LLDP frame, the
port must wait for the specified interval before it can send another one.
LLDP frame transmission delay must be less than the TTL to make sure the LLDP
neighbors can receive LLDP frames to update information about the device you
are configuring before it is aged out.
Set the LLDP frame transmission interval.
If the product of the TTL multiplier and the LLDP frame transmission interval is
greater than 65535, the TTL carried in transmitted LLDP frames takes 65535
seconds. The likelihood exists that the LLDP frame transmission interval is greater
than TTL. You should avoid the situation, because the LLDP neighbors will fail to
receive LLDP frames to update information about the device you are configuring
before it is aged out.
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