DHCPDUMP(8)                User Contributed Software               DHCPDUMP(8)



NAME
       dhcpdump - DHCP packet dumper

SYNOPSIS
       dhcpdump [-h regular-expression] -i interface

DESCRIPTION
       This command parses the output of tcpdump to display the dhcp-packets
       for easier checking and debugging.

USAGE
       dhcpdump -i /dev/fxp0

       If you want to filter a specific Client Hardware Address (CHADDR), then
       you can specifiy it as a regular expressions:

       dhcpdump -i /dev/fxp0 -h ^00:c0:4f

       This will display only the packets with Client Hardware Addresses which
       start with 00:c0:4f.

OUTPUT
         TIME: 15:45:02.084272
           IP: 0.0.0.0.68 (0:c0:4f:82:ac:7f) > 255.255.255.255.67 (ff:ff:ff:ff:ff:ff)
           OP: 1 (BOOTPREQUEST)
        HTYPE: 1 (Ethernet)
         HLEN: 6
         HOPS: 0
          XID: 28f61b03
         SECS: 0
        FLAGS: 0
       CIADDR: 0.0.0.0
       YIADDR: 0.0.0.0
       SIADDR: 0.0.0.0
       GIADDR: 0.0.0.0
       CHADDR: 00:c0:4f:82:ac:7f:00:00:00:00:00:00:00:00:00:00
        SNAME: .
        FNAME: .
       OPTION:  53 (  1) DHCP message type         3 (DHCPREQUEST)
       OPTION:  54 (  4) Server identifier         130.139.64.101
       OPTION:  50 (  4) Request IP address        130.139.64.143
       OPTION:  55 (  7) Parameter Request List      1 (Subnet mask)
                                                     3 (Routers)
                                                    58 (T1)
                                                    59 (T2)

       At the option field, the first field is the value of the option, the
       second one (between brackets) is the length of the option-datafield,
       the third field is the name of the option, the fourth field is the data
       of the option.

RETURN VALUES
       Always 0.

NOTES
       Privileged access is often needed for accessing the interface.

BUGS
       Not all the parameter options are printed verbose, because of lack of
       documentation. Not all the options are tested, because of lack of
       clients/servers with these options. If you have a dump of one of them,
       please send them to me and I'll incorperate them.

THANKS TO
       Ralph Droms and Ted Lemons "The DHCP Handbook", ISBN 1-57870-137-6.

       Peter Apian-Bennewitz  for his Client Hardware
       Address filtering

AUTHOR
       Edwin Groothuis, edwin@mavetju.org (http://www.mavetju.org)

SEE ALSO
       dhcpd(8), tcpdump(1), RFC2132



perl v5.8.8                      23 June 2008                      DHCPDUMP(8)