Ethernet LLDP Example

Table of Contents

• Introduction
• Supported Combinations
  • Prerequisites
  • Build the example
  • HW Setup
  • Create a network between EVM and host PC
  • Run the example
  • LLDP verification
    • Verification #1 LLDPDU Tx interval and LLDPDU content (per one dest-mac-address)
    • Verification #2 Fast TX in case of new neighbor exist (per one dest-mac-address)
    • Verification #3 Delete neighbor info in case of Receiving LLDP shutdown (per one dest-mac-address)
    • Verification #4 Detected Neighbor info change (per one dest-mac-address)
    • Verification #5 Multiple Destination MAC addresses
• See Also

Introduction

This ethernet LLDP example illustrates the usage of LLDP IEEE 802.1AB stack with CPSW peripheral.

In this example, the DUT MAC port is connected to a neighbor PC which also have opensource lldp agent. Yang based configuration is also supported. Currently File System is not supported, will be added in future releases.

See also :Ethernet LLDP Stack - API and Integration Guide

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0_freertos
Toolchain	ti-arm-clang
Board	am64x-evm
Example folder	examples/networking/tsn/lldp_cpsw_app

Prerequisites

• EVM Board
• Cat6 ethernet cable
• PC with Linux Ubuntu OS with wireshark, docker installed
• The LLDP opensource https://github.com/lldpd/lldpd can be installed follow the guideline. But a quick start can be using docker:

  docker run --rm --net=host --uts=host \
             -v /etc/os-release:/etc/os-release \
             --cap-add=NET_RAW --cap-add=NET_ADMIN \
             --name lldpd \
             ghcr.io/lldpd/lldpd:latest

Build the example

Refer Ethernet TSN gPTP Examples to build the lldp example.

HW Setup

Refer Ethernet TSN gPTP Examples for HW Setup.

Create a network between EVM and host PC

EVM and PC has to connected directly as shown below using CAT6 or CAT5 cable

Local network between PC and EVM

PORT1 instead of PORT0 on EVM can be used as well.

Run the example

Attention

If you need to reload and run again, a CPU power-cycle is MUST

Refer :Ethernet LLDP Stack - API and Integration Guide for how to configure LLDP parameters.

LLDP verification

Verification #1 LLDPDU Tx interval and LLDPDU content (per one dest-mac-address)

With default setting

{"message-tx-interval" , "30"},

Capture LLDPDU via wireshark and confirm the TX interval is around 30s

LLDP TX Interval

Capture LLDPDU via wireshark and confirm the LLDPDU content is match with configuration params in lldp_init.c

LLDPDU Content

Verification #2 Fast TX in case of new neighbor exist (per one dest-mac-address)

On Linux PC, start opensource LLDP application by:

docker run --rm --net=host --uts=host \
           -v /etc/os-release:/etc/os-release \
           --cap-add=NET_RAW --cap-add=NET_ADMIN \
           --name lldpd \
           ghcr.io/lldpd/lldpd:latest

With default setting

{"message-fast-tx" , "1"},
{"tx-fast-init" , "2"},

Capture LLDPDU via wireshark and confirm after receive Linux PC LLDPDU, the DUT process fast tx flow by one TX LLDPDU immediately, and follow up by two (tx-fast-init) more LLDPDUs, with one second interval (message-fast-tx).

LLDPDU Fast TX Flow

After receive next LLDPDU from Linux PC, no more fast tx flow happened on DUT side.

Verification #3 Delete neighbor info in case of Receiving LLDP shutdown (per one dest-mac-address)

Continue 2nd verification, then turn OFF LLDPDU by Ctrl + C in Linux PC docker command. Verify DUT can detect and delete correct neighbor info include Port and Chassis ID.

DUT log

INF:lldp:collect_ttl_info: Recv SHUTDOWN LLDPDU TTL=[0]
INF:lldp:tilld0: Process shutdown for existed neighbor:
INF:lldp:chassis id: bc-5f-f4-73-e5-5a
INF:lldp:port id:    1c-fd-08-72-59-61

User can rerun 2nd verification and confirm Fast TX flow happen again.

Verification #4 Detected Neighbor info change (per one dest-mac-address)

On Linux PC side, change port description of corresponding port which is connect to DUT. In this example, enp3s0 is used.

docker exec lldpd lldpcli configure port enp3s0 lldp portdescription xxxxxxx

DUT log

INF:lldp:is_remote_system_data_change: Detected port desc changed
INF:lldp:tilld0: Got updated for neighbor [TTL=120]:
INF:lldp:chassis id: bc-5f-f4-73-e5-5a
INF:lldp:port id:    1c-fd-08-72-59-61
INF:lldp:update_remote_system_data: changed port_desc [enp3s0-> xxxxxxx]

Verification #5 Multiple Destination MAC addresses

Configure 3 message-tx-interval values differently each other, like below:

{
.dest_mac = "01-80-c2-00-00-0e",
    {"message-tx-interval" , "30"},
}
 
{
.dest_mac = "01-80-c2-00-00-03",
    {"message-tx-interval" , "20"},
}
 
{
.dest_mac = "01-80-c2-00-00-00",
    {"message-tx-interval" , "25"},
}

Capture wireshark and verify the tx interval flow for:

• Nearest bridge 01-80-C2-00-00-0E (LLDP Multicast) is 30s
• Nearest non-TPMR bridge 01-80-C2-00-00-03 is 20s
• Nearest Customer Bridge (Spanning-tree-(for-bridges)_00) 01-80-C2-00-00-00 is 25s

LLDP Multiple Destination MAC Addresses

Repeat verification #1 -> #4 (The LLDP opensource is using Nearest bridge 01-80-C2-00-00-0E as destination MAC address) and confirm only Nearest bridge Dest MAC address in DUT takes effect.

See Also

Ethernet And Networking | Ethernet LLDP Stack - API and Integration Guide