3650 LLDP

[YC2]

Running 16.12.05b if that makes a difference.

Config guide 

First time using LLDP. The configuration guide has me believing that you have to do lldp run to enable it globally, then lldp transmit and lldp receive on the desired interfaces.

It appears "lldp run" enables it on all interfaces by default and they start processing lldp. This seems to be opposite of what the guide indicates. If I apply "lldp transmit" and "lldp receive" on desired interfaces, a show run or show run all does not show it. If I apply "no lldp transmit" a show run does show it. 

Is this just a documentation bug, or am I misunderstanding something?

[Edson A. Hernandez]

In Cisco IOS, the lldp run command indeed enables LLDP globally on the device. By default, when LLDP is enabled globally, it is typically active transmit and receive on all supported interfaces unless otherwise configured.

you generally do not need to manually enable transmit and receive on each interface because they are enabled by default that's normal behavior

[Leo Laohoo]

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@YC2 wrote:
If I apply "lldp transmit" and "lldp receive" on desired interfaces, a show run or show run all does not show it. 

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"sh run ALL" will show the hidden commands.

[YC2]

sh run all does NOT (at least in this specific scenario) show "lldp receive" or "lldp transmit". Below is console output from a 3650, with the global lldp run enabled, and the uplinks disabled. Result is the same if you manually apply lldp receive/transmit on a per interface basis

[Leo Laohoo]

Ok, I can see this same behaviour on a 3850 with 16.12.10a & a 9300 on 17.3.4. However, I can see the hidden LLDP commands with a 9300 on 17.9.3.

[YC2]

Doesn't look like 17.x is available for 3650's seeing as end of software support was about a year ago.  Hey boss, show commands are broke on our 3650's, got cash for some 9xxx??? lol

I guess the hidden commands not showing isn't a big deal. It's just the miss-documentation that threw me off course.

[Leo Laohoo]

The last firmware for 3650/3850 is 16.12.X.  

[Edson A. Hernandez]

It is the default behavior, similar to the 'no shutdown' command that you use on interfaces. If you apply 'no shutdown' to an interface, the command does not appear in the 'show run' nor in the 'show run all

[YC2]

Few things to that - 

1. I don't recall off the top of my head - but one of the Cisco platforms did indeed show a no shutdown in the show run. Maybe nexus or asr?

2. As Leo pointed out - the behavior seems different per platform

3. Usually Cisco is very precise in their documentation. My gripe isn't necessarily that it doesn't show, but rather what was documented - Check the release notes - step 5/6 (interface level commands) are shown as mandatory when they really are not. Check step 9, it specifies optional.

Long story short - looks like, to only enable LLDP on the desired interfaces, you have to lldp run in global, no lldp trans/rec for all interfaces, then lldp trans/rec for the desired interfaces.

[Leo Laohoo]

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@YC2 wrote:
3. Usually Cisco is very precise in their documentation. 

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No longer the case for the last 10 years.  

Cisco has allowed documentation to degrade and this trend will continue. 

In my personal opinion, Cisco will be turning customers to other people's website for reference.