dhcpdump(8)

1DHCPDUMP(8)                User Contributed Software               DHCPDUMP(8)
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NAME

6       dhcpdump - DHCP packet dumper
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SYNOPSIS

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

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

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

57       Always 0.
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NOTES

60       Privileged access is often needed for accessing the interface.
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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.
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THANKS TO

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

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