1.\" $OpenBSD: dhcp.8,v 1.24 2008/06/08 03:03:37 jdixon Exp $ 2.\" $DragonFly: src/share/man/man8/dhcp.8,v 1.3 2008/10/15 12:48:34 matthias Exp $ 3.\" 4.\" 5.\" Copyright (c) 1999 Aaron Campbell 6.\" All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.Dd October 15, 2008 30.Dt DHCP 8 31.Os 32.Sh NAME 33.Nm dhcp 34.Nd configuring DragonFly for DHCP 35.Sh DESCRIPTION 36The Dynamic Host Configuration Protocol (DHCP) allows hosts on a TCP/IP network 37to configure one or more network interfaces based on information collected from 38a DHCP server in response to a DHCP request. 39This mechanism is often used, for example, by cable modem and DSL network 40providers to simplify network configurations for their clients/customers. 41.Pp 42Information typically contained within a DHCP response includes an IP 43address for the interface, subnet mask, broadcast address, router (gateway) 44listing, domain name server listing, and the interface's MTU. 45.Pp 46To set up 47.Dx 48as a DHCP client: 49.Bl -enum -offset indent 50.It 51For each interface that is to be configured via DHCP, add 52.Dq Li DHCP 53to the 54.Va ifconfig_ Ns Aq Ar interface 55variable in 56.Pa /etc/rc.conf . 57See 58.Xr rc.conf 5 59for more information on the format of this file. 60.Pp 61The 62.Pa /etc/network.subr 63script reads each of these variables at boot-time and runs the 64.Xr dhclient 8 65program for each interface that is to be configured via DHCP. 66.It 67[Optional] To tweak settings, edit 68.Pa /etc/dhclient.conf . 69This file is shipped with the system. 70See 71.Xr dhclient.conf 5 72and 73.Xr dhclient 8 74for details. 75.El 76.Pp 77To set up 78.Dx 79as a DHCP server: 80.Bl -enum -offset indent 81.It 82Install 83.Xr dhcpd 8 84(available in 85.Xr pkgsrc 7 ) . 86.It 87Edit 88.Pa /usr/pkg/etc/dhcp/dhcpd.conf . 89See 90.Xr dhcpd.conf 5 91and 92.Xr dhcpd 8 93for details. 94.It 95Edit 96.Pa /etc/rc.conf 97and set 98.Cm dhcpd_flags="" . 99This will cause 100.Dx 101to start the 102.Xr dhcpd 8 103daemon at boot-time and listen for DHCP requests on the local network. 104To start it manually, execute the following command: 105.Pp 106.Dl # /usr/pkg/sbin/dhcpd [netif1 netif2 ...] 107.El 108.Pp 109The DHCP client and server use the Berkeley Packet Filter (BPF). 110Ensure the kernel has been compiled with BPF support 111and at least one 112.Pa /dev/bpf* 113file exists per broadcast network interface that is attached to the system. 114This is almost always the case and should only be considered if all other 115troubleshooting options have failed. 116.Pp 117See 118.Xr dhcpd 8 119for information on other available options. 120Note, however, that most of the flags are useful only for debugging purposes. 121.Sh FILES 122.Bl -tag -width /usr/pkg/etc/dhcpd.conf 123.It Pa /usr/pkg/etc/dhcp/dhcpd.conf 124DHCP server configuration file 125.It Pa /etc/rc.conf 126configuration file where 127DHCP client configuration is set for individual interfaces and 128.Cm dhcpd_flags 129must be set 130.It Pa /etc/dhclient.conf 131DHCP client configuration file 132.El 133.Sh SEE ALSO 134.Xr dhclient.conf 5 , 135.Xr dhcpd.conf 5 Pq Pa pkgsrc/net/isc-dhcpd4 , 136.Xr dhclient 8 , 137.Xr dhcpd 8 Pq Pa pkgsrc/net/isc-dhcpd4 , 138.Xr dhcrelay 8 Pq Pa pkgsrc/net/isc-dhcrelay4 139