root@ls1028ardb:~# uname -a
Linux ls1028ardb 5.10.72-rt53+gd1435e3ef8af #1 SMP PREEMPT_RT Thu Mar 10 11:07:07 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
root@ls1028ardb:~# cat /etc/os-release 
ID=nxp-real-time-edge
NAME="NXP Real-time Edge Distro"
VERSION="2.2 (hardknott)"
VERSION_ID=2.2
PRETTY_NAME="NXP Real-time Edge Distro 2.2 (hardknott)"


1. Send packets with multicast address: 224.0.0.255
root@ls1028ardb:~# ifconfig
eno2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1520
        inet6 fe80::24e4:2ff:fe2d:40c0  prefixlen 64  scopeid 0x20<link>
        ether 26:e4:02:2d:40:c0  txqueuelen 1000  (Ethernet)
        RX packets 917  bytes 87234 (85.1 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 128  bytes 25625 (25.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 60  bytes 6637 (6.4 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 60  bytes 6637 (6.4 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

swp0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        inet 192.168.0.129  netmask 255.255.255.0  broadcast 192.168.0.255
        inet6 fe80::24e4:2ff:fe2d:40c0  prefixlen 64  scopeid 0x20<link>
        ether 26:e4:02:2d:40:c0  txqueuelen 1000  (Ethernet)
        RX packets 917  bytes 56056 (54.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 77  bytes 13835 (13.5 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

root@ls1028ardb:~# ifconfig swp0 hw ether e6:c5:d2:6b:78:50

root@ls1028ardb:~# tcpdump -i swp0 udp
12:55:28.222276 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.322632 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.422883 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.522820 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.622998 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.723191 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7
12:55:28.823662 IP 192.168.0.10.8000 > 224.0.0.255.8001: UDP, length 7





官方镜像与底板：
root@ls1028ardb:~# uname -a
Linux ls1028ardb 5.10.72-rt53+gd1435e3ef8af #1 SMP PREEMPT_RT Thu Mar 10 11:07:07 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
root@ls1028ardb:~# cat /etc/os-release
ID=nxp-real-time-edge
NAME="NXP Real-time Edge Distro"
VERSION="2.2 (hardknott)"
VERSION_ID=2.2
PRETTY_NAME="NXP Real-time Edge Distro 2.2 (hardknott)"

1. Send packets with multicast address: 224.0.0.255
tcpdump -exxx -i swp0:
05:32:53.108333 50:eb:f6:b2:84:e4 (oui Unknown) > 01:00:5e:00:00:ff (oui Unknown), ethertype IPv4 (0x0800), length 60: 192.168.3.20.12 > 224.0.0.255.0: UDP, length 7
        0x0000:  0100 5e00 00ff 50eb f6b2 84e4 0800 4500
        0x0010:  0023 1a98 0000 0111 fa76 c0a8 0314 e000
        0x0020:  00ff 000c 0000 000f a0bd 666f 726c 696e
        0x0030:  7800 0000 0000 0000 0000 0000
05:32:53.208107 50:eb:f6:b2:84:e4 (oui Unknown) > 01:00:5e:00:00:ff (oui Unknown), ethertype IPv4 (0x0800), length 60: 192.168.3.20.12 > 224.0.0.255.0: UDP, length 7
        0x0000:  0100 5e00 00ff 50eb f6b2 84e4 0800 4500
        0x0010:  0023 1a99 0000 0111 fa75 c0a8 0314 e000
        0x0020:  00ff 000c 0000 000f a0bd 666f 726c 696e
        0x0030:  7800 0000 0000 0000 0000 0000