(1) AIX 4.x's version of BPF is undocumented and somewhat unstandard; the
    current BPF support code includes changes that should work around
    that, but, lacking an AIX machine on which to compile it, we don't
    know whether the BPF support for AIX will compile.

    If it doesn't, or if the workarounds fail to make it work correctly,
    you should send to tcpdump-workers@tcpdump.org a detailed bug report
    (if the compile fails, send us the compile error messages; if it
    compiles but fails to work correctly, send us as detailed as
    possible a description of the symptoms, including indications of the
    network link-layer type being wrong or time stamps being wrong).

    If you fix the problems yourself, please send to patches@tcpdump.org
    a patch, so we can incorporate them into the next release.

    If you don't fix the problems yourself, you can, as a workaround,
    make libpcap use DLPI instead of BPF.

    This can be done by specifying the flag:

       --with-pcap=dlpi

    to the "configure" script for libpcap.

(2) Also, it is a good idea to have the latest version of the DLPI
    driver on your system, since certain versions may be buggy and
    cause your AIX system to crash.  DLPI is included in the
    fileset bos.rte.tty.  I found that the DLPI driver that came with
    AIX 4.3.2 was buggy, and had to upgrade to bos.rte.tty 4.3.2.4:

    lslpp -l bos.rte.tty

    bos.rte.tty     4.3.2.4  COMMITTED  Base TTY Support and Commands

    Updates for AIX filesets can be obtained from:
    ftp://service.software.ibm.com/aix/fixes/

    These updates can be installed with the smit program.

(3) After compiling libpcap, you need to make sure that the DLPI driver
    is loaded.  Type:

    strload -q -d dlpi

    If the result is:
    dlpi: yes

    then the DLPI driver is loaded correctly.

    If it is:
    dlpi: no

    Then you need to type:
    strload -f /etc/dlpi.conf
 
    Check again with strload -q -d dlpi that the dlpi driver is loaded.  

    Alternatively, you can uncomment the lines for DLPI in
    /etc/pse.conf and reboot the machine; this way DLPI will always
    be loaded when you boot your system.