Any ideas why this rule won't parse?

ipfw add 10 deny ip from \{ not and not \} to any 53 out xmit wan0

ipfw doesn't like and and says: ipfw: missing ")"

I've tried other variants, for example, putting the not in front of the brace expression, putting the two IPs in a table and then saying not table(xyzzy) and nothing will work.

Is there a way to express this with ipfw?

  • Placing and inside braces is not valid syntax. Placing not in front of braces is not valid syntax. However, placing not in front of a table declaration should be valid. Jan 29, 2021 at 10:30
  • Additionally, sets of alternative match patterns (or-blocks) can be constructed by putting the patterns in lists enclosed between parentheses ( ) or braces { }, and using the or operator as follows: ipfw add 100 allow ip from { x or not y or z } to any (Citing from ipfw(5) )
    – pnadeau
    Feb 1, 2021 at 21:02
  • Exactly, you have used and, but the manual only mentions using or. Feb 1, 2021 at 21:07

1 Answer 1


As already mentioned in comments, inside an {...} or-block the individual options can only be grouped with or conditions. An and condition is implicitely assumed for all the present options, and a not condition can be prefixed to any single option. In the old syntax the rule would be written like this:

ipfw add 10 deny ip from not, to any 53 out xmit wan0

Alternatively, with the new syntax, which does not require from ... to, and instead consists only of a list of arbitrary options:

ipfw add 10 deny proto ip not src-ip not src-ip dst-port 53 out xmit wan0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.