This has come up a few times and the motivation is mainly better "first timer"
experience with Zeek. Concretely, if one wants to run a Zeek cluster with
multiple workers and reasonable load balancing on Linux, AF_PACKET is a decent
start. Without AF_PACKET support being built into Zeek, however, a new user's
next experience is that of setting up a development environment in order
to compile an external plugin (think compiler, kernel headers, zkg, ...).
Only to get what could be termed basic functionality.
This is using the ZEEK_INCLUDE_PLUGINS infrastructure. I've used the all
upper case spelling of AF_PACKET in the help output because it seems everyone
else references/writes it like that. I think we should also write it
like that in the docs.