Provides dump analysis and packet capturing.

    Format

      tcpdump  ["-B" | d | e | f | l | m | n | "-N" | "-O" | q | s |

               "-S" | t | v | x | "-X"]

               [-b buffers]

               [-c count]

               [-F file]

               [-r file]

               [-s snaplen]

               [-w file] expression