---
name: "dhcpdump"
section: "1"
platform: "linux"
package: "dhcpdump"
version: "1.7-1.1"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/dhcpdump"
---

# dhcpdump(1)

DHCP packet dumper

## 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)](/dhcpd/8.md), [*tcpdump*(1)](/tcpdump/1.md), RFC2132