lsof -i -n -P is a regular "reflex" command whenever I'm trying to figure out why a daemon I've just setup isn't responding to requests (immediately answers the

lsof -i -n -P is a regular "reflex" command whenever I'm trying to figure out why a daemon I've just setup isn't responding to requests (immediately answers the questions: is it running? and, if yes, under what privs? and on what interface?). That together with a dump of active iptables rules normally results in an immediate fix for 90% of "why can't I connect to X" problems :)