DHCPDUMP
NAMESYNOPSIS
DESCRIPTION
USAGE
OUTPUT
RETURN VALUES
NOTES
BUGS
THANKS TO
AUTHOR
SEE ALSO
NAME
dhcpdump − DHCP packet dumper
SYNOPSIS
dhcpdump [−h regular-expression]
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
If you want to filter a specific Client Hardware Address ( CHADDR ), then you can specifiy it as a regular expressions:
tcpdump −lenx −s 1500 port bootps or port bootpc | dhcpdump −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 tcpdump.
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 <apian@ise.fhg.de> for his Client Hardware Address filtering
AUTHOR
Edwin Groothuis, edwin@mavetju.org (http://www.mavetju.org)
SEE ALSO
dhcpd(8), tcpdump(1), RFC2132
More Linux Commands
manpages/XtGetSubresources.3.html
XtGetSubresources(3) - obtain subresources - Linux man page
The XtGetSubresources function constructs a name/class list from the application name/class, the name/classes of all its ancestors, and the widget itself. Then,
manpages/systemd.resource-control.5.html
systemd.resource-control(5) Resource control unit settings
Unit configuration files for services, slices, scopes, sockets, mount points, and swap devices share a subset of configuration options for resource control of s
manpages/asn1_encode_simple_der.3.html
asn1_encode_simple_der(3) API function - Linux manual page
Creates the DER encoding for various simple ASN.1 types like strings etc. It stores the tag and length in tl , which should have space for at least ASN1_MAX_TL_
manpages/systemd-initctl.service.8.html
systemd-initctl.service(8) dev initctl compatibility........
systemd-initctl is a system service that implements compatibility with the /dev/initctl FIFO file system object, as implemented by the SysV init system. systemd
manpages/snmp_fix_pdu.3.html
snmp_fix_pdu(3) - netsnmp_pdu_api functions - Linux man page
These functions deal with SNMP request structures. snmp_pdu_create snmp_clone_pdu snmp_fix_pdu snmp_free_pdu SEE ALSO varbind_api(3) session_api(3) snmp_fix_pdu
manpages/dmesg.1.html
dmesg(1) - print or control the kernel ring buffer (ManPage)
dmesg is used to examine or control the kernel ring buffer. The default action is to read all messages from the kernel ring buffer. OPTIONS The --clear, --read-
manpages/winebuild.1.html
winebuild(1) - Wine dll builder (Commands - Linux man page)
winebuild generates the assembly files that are necessary to build a Wine dll, which is basically a Win32 dll encapsulated inside a Unix library. winebuild has
manpages/sane-coolscan2.5.html
sane-coolscan2(5) - SANE backend for Nikon Coolscan film sca
The sane-coolscan2 library implements a SANE (Scanner Access Now Easy) backend that provides access to Nikon Coolscan film scanners. Some functions of this back
manpages/Tk_CanvasEventuallyRedraw.3.html
Tk_CanvasEventuallyRedraw(3) - utility procedures for canvas
These procedures are called by canvas type managers to perform various utility functions. Tk_CanvasTkwin returns the Tk_Window associated with a particular canv
manpages/gnutls_pkcs12_bag_deinit.3.html
gnutls_pkcs12_bag_deinit(3) - API function - Linux man page
This function will deinitialize a PKCS12 Bag structure. REPORTING BUGS Report bugs to <bug-gnutls@gnu.org>. GnuTLS home page: http://www.gnu.org/software/gnutls
manpages/iconv.1.html
iconv(1) - Convert encoding of given files from one encoding
The iconv program reads in text in one encoding and outputs the text in another encoding. If no input files are given, or if it is given as a dash (-), iconv re
manpages/Tcl_FSGetTranslatedPath.3.html
Tcl_FSGetTranslatedPath(3) - procedures to interact with any
There are several reasons for calling the Tcl_FS API functions (e.g. Tcl_FSAccess and Tcl_FSStat) rather than calling system level functions like access and sta
