configuration of ethernet + wifi

[rhaschke]

I have issues configuring DDS discovery for my setup, comprising two real-time machines connected with each other by Ethernet (subnet 192.168.10.x). Additionally, both machines have a wifi NIC (subnet 192.168.0.x) connecting them to a control laptop via wifi:

robot1                robot2                 laptop(s)
192.168.10.101        192.168.10.102         192.168.0.x
192.168.0.101         192.168.0.101     

Participants partially use ROS2 and partially native DDS communication.

Currently, we use the following DDS config on the robot PCs:

<?xml version="1.0" encoding="UTF-8"?>
<profiles xmlns="http://www.eprosima.com/XMLSchemas/fastRTPS_Profiles">
    <transport_descriptors>
        <transport_descriptor>
            <transport_id>udp_transport</transport_id>
            <type>UDPv4</type>
            <interfaceWhiteList>
                <address>127.0.0.1</address>
                <address>192.168.10.101</address>
                <address>192.168.10.102</address>
<!-- adding the wifi IPs as well, results in slow communication on both, Ethernet and wifi
                <address>192.168.0.101</address>
                <address>192.168.0.102</address>
-->
            </interfaceWhiteList>
        </transport_descriptor>

        <transport_descriptor>
            <transport_id>shm_transport</transport_id>
            <type>SHM</type>
            <segment_size>3198400</segment_size>
        </transport_descriptor>
    </transport_descriptors>

    <participant profile_name="booster_dds" is_default_profile="true">
        <rtps>
            <userTransports>
                <transport_id>udp_transport</transport_id>
                <transport_id>shm_transport</transport_id>
            </userTransports>
            <useBuiltinTransports>false</useBuiltinTransports>
        </rtps>
    </participant>

    <publisher profile_name="default publisher profile" is_default_profile="true">
        <qos>
            <data_sharing>
                <kind>AUTOMATIC</kind>
            </data_sharing>
        </qos>
    </publisher>

    <subscriber profile_name="default subscription profile" is_default_profile="true">
        <qos>
            <data_sharing>
                <kind>AUTOMATIC</kind>
            </data_sharing>
        </qos>
    </subscriber>
</profiles>

When adding the wifi NICs as well (currently commented out), discovery works but we observe extremely slow communication.
Also, I have read here that whitelisting multiple interfaces results in duplicate messages being send, which is obviously not desirable.
How should we configure DDS for fast and reliable communication? Any pointer to an example config would be helpful.