Ian Pilcher <i(dot)pilcher(at)comcast(dot)net> writes:
> Perhaps there's a bug in PostgreSQL's handling of IPv4-mapped sockets,
> or perhaps Linux reports it to PostgreSQL as an IPv4 socket ... or
> perhaps Red Hat is disabling PostgreSQL's IPv6 support in their RPMs.
Door number 2 seems to be the correct answer; see my followup just now.
(It's definitely not #3 ... I know, I build those RPMs.)
regards, tom lane