# # $Id: dhcpdump.pod,v 1.3 2003/11/20 11:52:59 mavetju Exp $ # =head1 NAME B - DHCP packet dumper =head1 SYNOPSIS B [B<-h> I] =head1 DESCRIPTION This command parses the output of tcpdump to display the dhcp-packets for easier checking and debugging. =head1 USAGE S If you want to filter a specific Client Hardware Address (CHADDR), then you can specifiy it as a regular expressions: S This will display only the packets with Client Hardware Addresses which start with 00:c0:4f. =head1 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. =head1 RETURN VALUES Always 0. =head1 NOTES Privileged access is often needed for tcpdump. =head1 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. =head1 THANKS TO Ralph Droms and Ted Lemons "The DHCP Handbook", ISBN 1-57870-137-6. Peter Apian-Bennewitz for his Client Hardware Address filtering =head1 AUTHOR Edwin Groothuis, edwin@mavetju.org (http://www.mavetju.org) =head1 SEE ALSO dhcpd(8), tcpdump(1), RFC2132