NAME

       pflog — packet filter logging interface

SYNOPSIS

       device pflog

DESCRIPTION

       The  pflog  interface  is  a  device  which makes visible all packets logged by the packet filter, pf(4).
       Logged packets can easily be monitored in real time by invoking tcpdump(1) on  the  pflog  interface,  or
       stored to disk using pflogd(8).

       The  pflog0  interface  is created automatically at boot if both pf(4) and pflogd(8) are enabled; further
       instances can be created using ifconfig(8).

       Each packet retrieved on this interface has a header associated with it  of  length  PFLOG_HDRLEN.   This
       header  documents  the  address family, interface name, rule number, reason, action, and direction of the
       packet that was logged.  This structure, defined in ⟨net/if_pflog.h⟩ looks like

             struct pfloghdr {
                     u_int8_t        length;
                     sa_family_t     af;
                     u_int8_t        action;
                     u_int8_t        reason;
                     char            ifname[IFNAMSIZ];
                     char            ruleset[PF_RULESET_NAME_SIZE];
                     u_int32_t       rulenr;
                     u_int32_t       subrulenr;
                     uid_t           uid;
                     pid_t           pid;
                     uid_t           rule_uid;
                     pid_t           rule_pid;
                     u_int8_t        dir;
                     u_int8_t        pad[3];
             };

EXAMPLES

       Create a pflog interface and monitor all packets logged on it:

             # ifconfig pflog1 up
             # tcpdump -n -e -ttt -i pflog1

SEE ALSO

       tcpdump(1), inet(4), inet6(4), netintro(4), pf(4), ifconfig(8), pflogd(8)

HISTORY

       The pflog device first appeared in OpenBSD 3.0.

Debian                                            May 31, 2007                                          PFLOG(4)