1DHCPDUMP(8)                User Contributed Software               DHCPDUMP(8)
2
3
4

NAME

6       dhcpdump - DHCP packet dumper
7

SYNOPSIS

9       dhcpdump [-h regular-expression] -i interface
10

DESCRIPTION

12       This command parses the output of tcpdump to display the dhcp-packets
13       for easier checking and debugging.
14

USAGE

16       dhcpdump -i /dev/fxp0
17
18       If you want to filter a specific Client Hardware Address (CHADDR), then
19       you can specifiy it as a regular expressions:
20
21       dhcpdump -i /dev/fxp0 -h ^00:c0:4f
22
23       This will display only the packets with Client Hardware Addresses which
24       start with 00:c0:4f.
25

OUTPUT

27         TIME: 15:45:02.084272
28           IP: 0.0.0.0.68 (0:c0:4f:82:ac:7f) > 255.255.255.255.67 (ff:ff:ff:ff:ff:ff)
29           OP: 1 (BOOTPREQUEST)
30        HTYPE: 1 (Ethernet)
31         HLEN: 6
32         HOPS: 0
33          XID: 28f61b03
34         SECS: 0
35        FLAGS: 0
36       CIADDR: 0.0.0.0
37       YIADDR: 0.0.0.0
38       SIADDR: 0.0.0.0
39       GIADDR: 0.0.0.0
40       CHADDR: 00:c0:4f:82:ac:7f:00:00:00:00:00:00:00:00:00:00
41        SNAME: .
42        FNAME: .
43       OPTION:  53 (  1) DHCP message type         3 (DHCPREQUEST)
44       OPTION:  54 (  4) Server identifier         130.139.64.101
45       OPTION:  50 (  4) Request IP address        130.139.64.143
46       OPTION:  55 (  7) Parameter Request List      1 (Subnet mask)
47                                                     3 (Routers)
48                                                    58 (T1)
49                                                    59 (T2)
50
51       At the option field, the first field is the value of the option, the
52       second one (between brackets) is the length of the option-datafield,
53       the third field is the name of the option, the fourth field is the data
54       of the option.
55

RETURN VALUES

57       Always 0.
58

NOTES

60       Privileged access is often needed for accessing the interface.
61

BUGS

63       Not all the parameter options are printed verbose, because of lack of
64       documentation. Not all the options are tested, because of lack of
65       clients/servers with these options. If you have a dump of one of them,
66       please send them to me and I'll incorperate them.
67

THANKS TO

69       Ralph Droms and Ted Lemons "The DHCP Handbook", ISBN 1-57870-137-6.
70
71       Peter Apian-Bennewitz <apian@ise.fhg.de> for his Client Hardware
72       Address filtering
73

AUTHOR

75       Edwin Groothuis, edwin@mavetju.org (http://www.mavetju.org)
76

SEE ALSO

78       dhcpd(8), tcpdump(1), RFC2132
79
80
81
82perl v5.36.0                     23 June 2008                      DHCPDUMP(8)
Impressum