I am using /dev/udp to send a udp packet. For example, (taken from this answer)
echo -n "This is a test" >/dev/udp/localhost/8000
I opened it up in wireshark to see what kind of packet encapsulation it uses and saw it isn't one I recognise. I haven't been able to identify what header format it's using. The protocol name in wireshark is "data".
I initially thought it was an IPv4 Pseudo header, due to the IP addresses and port numbers.
However, they don't match up exactly and this packet is also wrapped in additional "protocol name" and "end of options" fields. If the packet encapsulation name is "data", it isn't coming up in a google search.
Is there any documentation detailing what this encapsulation format is? Is it possible to change it to a different one (for example, an actual IPv4 pseudo header?)