LLDP – Time to Live (TTL) timers

[Bill]

I have a question on LLDP timers related to TTL (on Catalyst switches)

I’ve seen some references that the TTL is the multiple of the Transmit Timer times the Hold Time Multiplier.
Looking at my switch (an old 3650), I cannot see or set the Hold Time Multiplier.
I can set the LLDP Timer (5-65534 sec) and a Hold Timer (0-65535 sec).

Most references say the Hold Time Multiplier is usually between 2 and 10.

Is the Hold Timer the same as TTL ?
I am thinking it is, and we do not use a multiplier at all.
Is that correct ?

Using Wireshark, I see the TTL value and it equals the Hold Timer.
I do not see a multiplier value.

Wondering why so many references mention the multiplier.
Does Cisco use it?

Thanks

[MHM Cisco World]

TTL = min (65535 , lldp-timer x lldp-hold-multiple) 

Defualt of lldp timer is 30 and hold is 3 meaning ttl is 90 of lldp

MHM

[Bill]

Thanks for the quick response.
Can I configure the Hold value that you are referring to?

I do not see that value in my switch. But I do have 'LLDP holdtime'
The LLDP holdtime has a range of 0-65535 Seconds, so I am pretty sure it is not the same as the Hold multiplier you are referring to.

This is from my Cisco switch:

lldp ?
holdtime Specify the holdtime (in sec) to be sent in packets
reinit Delay (in sec) for LLDP initialization on any interface
run Enable LLDP
timer Specify the rate at which LLDP packets are sent (in sec)
tlv-select Selection of LLDP TLVs to send

If I drill into them:

lldp holdtime ?
<0-65535> Length of time (in sec) that receiver must keep this packet
The default is 120 seconds

lldp timer ?
<5-65534> Rate at which LLDP packets are sent (in sec)
The default is 30 seconds.

Looking at a different brand switch (Netgear) has these values.

Transmit Interval............................ 30 seconds Range <5 - 32768> seconds
Transmit Hold Multiplier..................... 4 Range <2 - 10>
Reinit Delay................................. 2 seconds Range <1 - 10> seconds
Notification Interval........................ 5 seconds Range <5 - 3600> seconds

The NetGear clearly has the multiplier. I do not see it with Cisco.

Thanks

[MHM Cisco World]

What is your SW platform?

MHM

[Bill]

I have looked at all these switches, and they all have the same options for configuring LLDP.
Same options as I listed previously.

C9300-48P running Version 16.12.02
C9500-32QC running Version 16.12.5
WS-C3850-48P running Version 03.06.06E
WS-C3560-8PC running Version 15.0(2)SE11
Thanks

[MHM Cisco World]

Not all cisco SW use hold-multii

For SW you list the holdtimer is direct enter in sec' where other SW you can config hold-timer by =lldp-timer x hold-multi

For example 

For SW allow 

Hold-multi is 3 and lldp-timer is 30 then holdtimer will be 90

For other SW 

Hold-timer 90 

Cisco for all protocl recommend to be hold timer three time the hello (lldp-timer)' you can see same in ospf' eigrp...etc.

MHM