ROS2 & discovery server : fails if running more than 100 nodes

[1r0b1n0]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

all nodes should be visible in "ros2 topic list" and "ros2 node list"
ros2 topic list|wc -l should show 112
ros2 node list|wc -l should shows 110

Current behavior

only the first 100 nodes are working:
ros2 topic list|wc -l shows 102
ros2 node list|wc -l shows 100

Steps to reproduce

Create a launch file named launch.py :

from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, OpaqueFunction
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node


def generate_talker_nodes(context):
    n = int(LaunchConfiguration('n').perform(context))
    nodes = []
    for i in range(1, n+1):
        nodes.append(
            Node(
                package='examples_rclcpp_minimal_publisher',
                executable='publisher_member_function',
                name=f'talker_{i}',
                namespace=f'talker_{i}',
                output='screen',
            )
        )
    return nodes


def generate_launch_description():
    return LaunchDescription([
        DeclareLaunchArgument(
            'n',
            default_value='5',
            description='Number of talker instances to launch'
        ),
        OpaqueFunction(function=generate_talker_nodes),
    ])

In ubuntu 24.04, install ROS2 Kilted then apt install ros-kilted-examples-rclcpp-minimal-publisher

In terminal A]

source /opt/ros/kilted/setup.bash
fastdds discovery

In terminal B]

export ROS_DISCOVERY_SERVER=UDPv4:[127.0.0.1]:11811
export FASTDDS_DEFAULT_PROFILES_FILE=/home/rov/super_client_configuration_file.xml

ros2 daemon stop
ros2 daemon start

In terminal C]

ros2 launch launch.py n:=110

Wait a minute, then again in Terminal B]

ros2 node list|wc -l
ros2 topic list|wc -l

Fast DDS version/commit

fastdds version : 3.2.3-1noble.20260224.230002 (ros2 kilted)
fastdds version : 3.4.2-1noble.20260130.183350 (ros2 rolling)

Platform/Architecture

Other. Please specify in Additional context section.

Transport layer

UDPv4

Additional context

OS: Ubuntu 24.04
Tested in ROS2 kilted (and also in ROS2 rolling)

XML configuration file

-> default config for the talker nodes
-> for ROS2 CLI tool (ros2 node list) : The `super_client_configuration_file.xml`, from this page : https://docs.ros.org/en/kilted/Tutorials/Advanced/Discovery-Server/Discovery-Server.html

Relevant log output

Network traffic capture

No response