udpsend bug ?
Hi,
I am experiencing a strange issue with [udpsend] in the current version of Max 9 on macOS.
The same patch works normally in Max 8: OSC messages are received by an ESP32-S3 when sent to its unicast IP address.
In Max 9, however:
- Broadcast works:
[udpsend 192.168.1.255 <port>]
- Unicast does not work:
[udpsend 192.168.1.20 <port>]
The receiver is an ESP32-S3, so there is no firewall on the receiving side. The ESP32 receives the broadcast packets correctly, but receives nothing when Max 9 is set to the specific IP address.
I also ran the following on the Mac while triggering the unicast message from Max 9:
sudo tcpdump -n -i en0 'udp and dst host 192.168.1.20 and dst port <port>'
tcpdump starts listening, but no matching packet is shown. This suggests that the unicast UDP packet is not leaving Max 9 at all.
Max 8, using the same patch, Mac, network, ESP32 IP address, and port, sends unicast correctly.
Has anyone else encountered a Max 9 / macOS issue where [udpsend] can broadcast but does not send unicast UDP packets? Is there a known permission, regression, or workaround?
System:
- macOS: 26.5.2
- Max: 9.1.5
- Network: Wi-Fi
- ESP32-S3 IP: 192.168.1.20
- UDP/OSC port: 8000
you probably checked that already: could you verify that the port is not uses by any other application and/or there is no IP address conflict in your network?
Did you try other ports?
Hi Jan,
Thank you for your answer.
Yes, I have already tested with ports 8000, 9000 and 7000. These ports are free, no IP address conflict.
Same thing, no change....
If udpsend is behaving oddly, I’d first check the destination IP and port on both ends and make sure nothing else is already using that port. A quick packet capture can also help confirm whether the UDP packets are actually leaving Max or getting lost somewhere along the way.