(Of course, if you only appended to /etc/hosts then the old address is still in there and getting used first..)

"files dns" in nsswitch.conf, and no prior /etc/hosts entry. i.e., this overrode DNS to the 192.168.* interface. netstat shows that (by now, at least) this has completely taken.

If this is happening even with slapd cleanly shut down then it should also prevent slapd from restarting, since slapd first attempts to join an existing environment before trying to create a new one. And that really implies that the rest of the environment is shot.

Agreed, but that's a pretty awful condition to have in a long-running slapd process. Without db_stat (easily) working, is there any hope at finding clues as to how this might have happened, or is it just time to rm/slapadd and hope it doesn't happen again?