I have opened a number of ports, and am familiar enough with pfctl, but even though I have opened various ports, then show up as "filtered" - which means of course that they are not open.

How can I open them, or is it a function of having a suitable app using them? For example

pass in proto tcp from any to any port 53

In a scan this shows up as

53 dns Filtered

How can I open this port?

1 Answer 1


Usually port scanners use UDP and TCP to scan port. Since most implementations of DNS servers use UDP you probably also have to open 53/udp:

pass in proto udp from any to any port 53
  • PORT STATE SERVICE 53/udp open|filtered domain 53/tcp Filtered Oct 17, 2015 at 11:15
  • the command above in pf.conf just opens the UDP port, doesn't change the "filtered" flag for tcp Oct 17, 2015 at 11:18

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .