Just a quick note about the package nullidentd. This is an Ident Daemon that purports to be as light as possible. In the man page you see mention that (and I quote — under OPTIONS):

nullidentd takes only one optional argument, the username to answer with. If this is omitted, nullidentd will reply with the username "foobar". If the username is RANDOM, a random string is generated.

And under USAGE:

nullidentd is typically invoked from inetd. The following is a typical inetd.conf example:
auth stream tcp nowait nobody /usr/sbin/nullidentd nullidentd

What you don’t see is the actual, proper use of adding a specified string or the magic RANDOM string.

The way? Add -u. Fairly straightforward, but undocumented. Even running nullidentd --help lists the usage as “nullidentd [uid].”

auth stream tcp nowait nobody /usr/sbin/nullidentd -u RANDOM

But once you figure it out it runs quite fine, no harm no foul. Still, it ought to announce proper syntax.

(For a quick and easy test, this works like a charm.)