3Com 2928 - Baseline Plus Switch PWR, User Manual

Page: 265 / 505

1-14
Item Description
TTL Multiplier
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 ×
LLDPDU transit interval
.
z
If the product of the TTL multiplier and the LLDPDU transmit interval is
greater than 65535, the TTL carried in transmitted LLDPDUs takes
65535 seconds.
z
As the maximum TTL allowed by CDP is 255 seconds, you must ensure
that the product of the TTL multiplier and the LLDPDU transmit interval is
less than 255 seconds for CDP-compatible LLDP to work properly with
Cisco IP phones.
Trap Interval
Set the minimum interval for sending traps.
With the LLDP trapping function enabled on a port, traps are sent out the
port to advertise the topology changes detected over the interval to
neighbors. By tuning this interval, you can prevent excessive traps from
being sent when topology is instable.
Reinit Delay
Set initialization delay for LLDP-enabled ports.
Each time the LLDP operating mode of a port changes, its LLDP protocol
state machine re-initializes. To prevent LLDP from being initialized too
frequently at times of frequent operating mode change, initialization delay is
introduced. With this delay mechanism, a port must wait for the specified
interval before it can initialize LLDP after the LLDP operating mode
changes.
Tx Delay
Set LLDPDU transmit delay.
With LLDP enabled, a port advertises LLDPDUs to its neighbors both
periodically and when the local configuration changes. To avoid excessive
number of LLDPDUs caused by frequent local configuration changes, an
LLDPDU transmit delay is introduced. Thus, after sending an LLDPDU, the
port must wait for the specified interval before it can send another one.
LLDPDU transmit delay must be less than the TTL to ensure that the LLDP
neighbors can receive LLDPDUs to update information about the device
you are configuring before it is aged out.
Tx Interval
Set the LLDPDU transmit interval.
If the product of the TTL multiplier and the LLDPDU transmit interval is
greater than 65535, the TTL carried in transmitted LLDPDUs takes 65535
seconds. In this case, the likelihood exists that the LLDPDU transmit
interval is greater than TTL. You should avoid the situation, because the
LLDP neighbors will fail to receive LLDPDUs to update information about
the device you are configuring before it is aged out.
Return to
LLDP Configuration Task List .
Displaying LLDP Information for a Port
Select
Network
>
LLDP
from the navigation tree to enter the
Port Setup
tab, as shown in Figure 1-4 . In
the port list click a port name to display its LLDP information at the lower half of the page. The LLDP