Windows Version
Microsoft Windows [Version 10.0.22631.4249]
WSL Version
2.0.14.0
Are you using WSL 1 or WSL 2?
Kernel Version
5.15.133.1-1
Distro Version
Ubuntu 22.04
Other Software
Wireshark Version 4.2.3
Repro Steps
First create a .wslconfig config file and set networkingMode=mirrored under [wsl2] as per https://learn.microsoft.com/en-us/windows/wsl/networking#mirrored-mode-networking. File should look like
[wsl2]
networkingMode=mirrored
Shutdown and restart wsl2
In wsl2 run program that sends UDP packets to a valid multicast address. I'm using the following python script:
import socket
import struct
import time
MULTICAST_GROUP = '224.1.1.1' # Change to your desired multicast address
PORT = 5004 # Change to your desired port
# Create the socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
# Set the socket option to allow multicast
sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 2)
# Send multicast packets
while True:
message = b'This is a multicast message'
sock.sendto(message, (MULTICAST_GROUP, PORT))
print(f'Sent: {message}')
time.sleep(1) # Send a packet every secondIn separate powershell terminal, run program that reads from the same multicast address. I'm using the following python scripts:
import socket
import struct
MULTICAST_GROUP = '224.1.1.1' # Match the address used in the sender
PORT = 5004 # Match the port used in the sender
# Create the socket
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(('', PORT))
# Tell the operating system to add the socket to the multicast group
group = socket.inet_aton(MULTICAST_GROUP)
mreq = struct.pack('4sL', group, socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
print(f'Ready to receive on {MULTICAST_GROUP}:{PORT}')
# Receive multicast packets
while True:
data, addr = sock.recvfrom(1024) # Buffer size is 1024 bytes
print(f'Received message: {data} from {addr}')Expected Behavior
Receiving script should correctly read packets from multicast address. When both programs are run on powershell, output of receiving script will look like this:
The source ip address will be the ip address from wsl2
Actual Behavior
Receiving script receives no packets. This behavior is particularly strange as Wireshark is able to see these packets
Note that the source ip address is that of eth1, output of ip addr in wsl2:
Diagnostic Logs
No response
Windows Version
Microsoft Windows [Version 10.0.22631.4249]
WSL Version
2.0.14.0
Are you using WSL 1 or WSL 2?
Kernel Version
5.15.133.1-1
Distro Version
Ubuntu 22.04
Other Software
Wireshark Version 4.2.3
Repro Steps
First create a
.wslconfigconfig file and setnetworkingMode=mirroredunder[wsl2]as per https://learn.microsoft.com/en-us/windows/wsl/networking#mirrored-mode-networking. File should look likeShutdown and restart wsl2
In wsl2 run program that sends UDP packets to a valid multicast address. I'm using the following python script:
In separate powershell terminal, run program that reads from the same multicast address. I'm using the following python scripts:
Expected Behavior
Receiving script should correctly read packets from multicast address. When both programs are run on powershell, output of receiving script will look like this:
The source ip address will be the ip address from wsl2
Actual Behavior
Receiving script receives no packets. This behavior is particularly strange as Wireshark is able to see these packets
Note that the source ip address is that of eth1, output of
ip addrin wsl2:Diagnostic Logs
No response