cpghost wrote:
How can I watch /var/log/pflog grow with tcpdump, "tail -f" style?

This won't work:
  $ tail -f /var/log/pflog | tcpdump -n -s 116 -r -
because tail doesn't start at the right location.

Using a blocksize (-b) with tail may also not be right,
because the captured packets are not the same size.

This seems to work:
  $ tcpdump -n -s 116 -i pflog0
but now, both tcpdump and pflogd are competing for the same
interface pflog0.

I'm afraid that in the latter case, every packet will be
  EITHER logged by pflogd
  XOR    displayed by tcpdump.
Is that so?

If yes, /var/log/pflog would be incomplete, because some packets
would have been snatched away from pflog0 by tcpdump, before
pflogd ever got a chance to read them out.

Is there a way to watch /var/log/pflog grow, while
still making sure that pflogd logs EVERY packet that appears
on the pflog0 interface? How?

Running tcpdump against the pflog0 pseudo-interface no more stops
pflogd recording the traffic than running tcpdump on your network
interface blocks traffic from the net.

  tcpdump -vv -i pflog0

really is the way to go if you want to see what your firewall is
logging in real time.



Dr Matthew J Seaman MA, D.Phil.                   7 Priory Courtyard
                                                 Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey     Ramsgate
                                                 Kent, CT11 9PW

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