Ahh, you mean the magic bytes which identify the network it uses.
The easiest way to see what the magic bytes are is to just connect to the node. The first 4 bytes that they send are the magic bytes. The messages of every altcoin based on Bitcoin are basically the same format, so it should be fairly trivial to get the magic bytes as they are the first four bytes of every message.
Please read, and understand my first post.
A node does not broadcast these bytes; unless another node (running identical netcode) sends these same bytes (and version info) first.
If i connect to an altcoin node on its P2P port, it will sit there and say nothing until a timeout occurs.
just found a random bitcoin node, hit it using telnet/raw (on 8333)... connects, and sits there, til timeout.
does anyone know how to get a given node to voluntarily spit out its pchMessageBytes?
Knight was looking for "pchMessageBytes" as you'd asked about, not "pchMessageStart" and pch messages are all over net.cpp
pchMessageStart[0] = 0xf8;
pchMessageStart[1] = 0xb5;
pchMessageStart[2] = 0x03;
pchMessageStart[3] = 0xdf;
yes; a seasoned programmer would instantly know what i'm referring to. bytes, four of them.