shmif_dumpbus —
examine shmif bus contents
  
    | shmif_dumpbus | [ -h] [-ppcapfile] busfile | 
The shmif_dumpbus utility examines the bus of an
  shmif(4) Ethernet interface. The
  most useful feature is converting the bus to the
  pcap(3) file format for later
  examination. shmif_dumpbus itself is limited to
  displaying only very basic information about each frame.
shmif_dumpbus accepts the following
  flags:
  - -h
- Print bus header only and skip contents.
- -ppcapfile
- Convert bus contents to the
      pcap(3) format and write the
      result to pcapfile. The file
      -signifies stdout.
Feed the busfile contents to pcap:
$ shmif_dumpbus -p - busfile | tcpdump -r -
 
shmif_dumpbus does not lock the busfile and is best used
  for post-mortem analysis of the bus traffic.
The timestamp for each frame contains the sender's timestamp and
    may not be monotonically increasing with respect to the frame order in the
    dump.