DHCPDUMP(1)

NAME
dhcpdump - DHCP packet dumper

SYNOPSIS
dhcpdump [command]

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

USAGE
tcpdump -lenx -s 1500 port bootps or port bootpc | dhcpdump

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
 HTYPE: 1
  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    011c02030f060c
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 tcpdump.

BUGS
Not all the options are printed verbose, because of lack of documentation. Not all the options are tested, because of lack of clients/servers with these options.

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

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

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