R2511-HP MSR Router Series Layer 2 - LAN Switching Configuration Guide(V5)
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By setting the TTL multiplier, you can configure the TTL of locally sent LLDPDUs, which determines how
long information about the local device can be saved on a neighboring device. The TTL is calculated with
the following formula:
TTL = Min (65535, (TTL multiplier × LLDPDU transmit interval))
As shown in the expression, the TTL can be up to 65535 seconds. TTLs greater than 65535 will be
rounded down to 65535 seconds.
Configuration restrictions and guidelines
• To make sure that LLDP neighbors can receive LLDPDUs to update information about the current
device before it ages out, configure both the LLDPDU transmit delay to be less than the TTL.
• It is a good practice to set the LLDPDU transmit interval to be no less than four times the LLDPDU
transmit delay.
• If the LLDPDU transmit delay is greater than the LLDPDU transmit interval, the device uses the
LLDPDU transmit delay as the transmit interval.
Configuration procedure
To change LLDP parameters:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Set the TTL multiplier.
lldp hold-multiplier value
Optional.
The default setting is 4.
3. Set the LLDPDU transmit
interval.
lldp timer tx-interval interval
Optional.
The default setting is 30
seconds.
4. Set the LLDPDU transmit delay.
lldp timer tx-delay delay
Optional.
The default setting is 2 seconds.
5. Set the number of LLDPDUs
sent each time fast LLDPDU
transmission is triggered.
lldp fast-count count
Optional.
The default setting is 3.
Setting an encapsulation format for LLDPDUs
LLDPDUs can be encapsulated in the following formats:
• Ethernet II encapsulation—An LLDP port sends LLDPDUs in Ethernet II frames and processes only
incoming, Ethernet II encapsulated LLDPDUs.
• SNAP encapsulation—An LLDP port sends LLDPDUs in SNAP frames and processes only incoming,
SNAP encapsulated LLDPDUs.
By default, LLDPDUs are encapsulated in Ethernet II frames. If neighbor devices encapsulate LLDPDUs in
SNAP frames, configure the encapsulation format for LLDPDUs as SNAP to guarantee normal
communication with neighbors.
LLDP-CDP (Cisco Discovery Protocol) packets use only SNAP encapsulation.
To set the encapsulation format for LLDPDUs to SNAP: