Seems you had a process still using the camera, or tried an unsupported mode, or you’ve crashed nvargus camera deamon, or …
In my case it works using a Jetson with a monitor attached and a GUI session opened (this might make a diference for argus) for streaming with:
gst-launch-1.0 -ev nvarguscamerasrc ! nvv4l2h264enc insert-vui=1 ! h264parse ! rtph264pay config-interval=1 pt=96 ! udpsink host=224.1.1.1 auto-multicast=true port=5000
Then, from another host on same LAN, I’ve edited my test.sdp so that I give multicast address 224.1.1.1:
m=video 5000 RTP/AVP 96
c=IN IP4 224.1.1.1
a=rtpmap:96 H264/90000
then using vlc test.sdp works.
If it doesn’t work, you may ask your network admin for a multicast address and firewall rules if any.