lsof and listening ports

sudo lsof -iTCP -sTCP:LISTEN
sudo lsof -iTCP -sTCP:LISTEN -P
sudo lsof -iTCP -sTCP:LISTEN -P -n
sudo lsof -iTCP -sTCP:LISTEN -n

All return the same 32 entries (... | wc -l) on my heavily used Lion MBP.

-P -n prevents lsof from doing name resolution, and it doesn't block. Missing either one of these, it can be very slow.

For UDP: sudo lsof -iUDP -P -n | egrep -v '(127|::1)'. Without -n and -P, it takes a long time.

Reminder: This does not include firewall settings.

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