1.\" $OpenBSD: dhcrelay6.8,v 1.2 2017/03/17 16:45:27 jmc Exp $ 2.\" 3.\" Copyright (c) 1997 The Internet Software Consortium. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of The Internet Software Consortium nor the names 16.\" of its contributors may be used to endorse or promote products derived 17.\" from this software without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND 20.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 21.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 22.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 23.\" DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR 24.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 27.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 28.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" This software has been written for the Internet Software Consortium 34.\" by Ted Lemon <mellon@fugue.com> in cooperation with Vixie 35.\" Enterprises. To learn more about the Internet Software Consortium, 36.\" see ``http://www.isc.org/isc''. To learn more about Vixie 37.\" Enterprises, see ``http://www.vix.com''. 38.\" 39.Dd $Mdocdate: March 17 2017 $ 40.Dt DHCRELAY6 8 41.Os 42.Sh NAME 43.Nm dhcrelay6 44.Nd Dynamic Host Configuration Protocol relay agent 45.Sh SYNOPSIS 46.Nm 47.Op Fl dlov 48.Op Fl E Ar enterprise-number 49.Op Fl I Ar interface-id 50.Op Fl R Ar remote-id 51.Fl i Ar interface 52.Ar destination ... 53.Sh DESCRIPTION 54The 55.Nm 56utility provides a means for relaying DHCPv6 requests from a subnet to 57which no DHCP server is directly connected to one or more DHCPv6 servers 58on other subnets. 59.Pp 60.Nm 61listens for DHCPv6 requests on a given interface. 62When a query is received, 63.Nm 64forwards it to the list of DHCP destinations specified on the command 65line. 66When a reply is received, it is sent on the network from whence the 67original request came. 68.Pp 69The 70.Ar destination 71might be an address followed by a `%' and an interface name, 72or just an interface name (e.g. "2001:db8::1%em0" or "em1"). 73When no address is specified 74.Nm 75will use multicast on the specified interface. 76.Pp 77The options are as follows: 78.Bl -tag -width Ds 79.It Fl d 80Do not daemonize. 81If this option is specified, 82.Nm 83will run in the foreground and log to 84.Em stderr . 85.It Fl E Ar enterprise-number 86Choose the 87.Ar enterprise-number 88that will be used by the Remote-ID option (this only has effect when using 89.Fl R ) . 90.It Fl I Ar interface-id 91The 92.Ar interface-id 93relay agent information option value that 94.Nm 95should use on relayed packets. 96If this option is not specified it will use the interface name by 97default. 98.Pp 99Avoid using this option when using Lightweight DHCPv6 Relay Mode 100(layer 2 relay), otherwise 101.Nm 102will always send replies back to the client interface, which will break 103networks with multiple DHCPv6 layer 2 relay agents. 104.It Fl i Ar interface 105The name of the network interface 106which will receive client DHCPv6 requests. 107For layer 3 mode at least one IPv6 local, site or global address has to 108be configured on this interface. 109.It Fl l 110Use the Lightweight DHCPv6 Relay Agent mode (layer 2 relaying). 111.It Fl o 112Add the Interface-ID option. 113This option is activated by default when using layer 2 relaying. 114.It Fl R Ar remote-id 115Enable and add the specified Relay Agent 116.Ar remote-id 117to identify this relay segment. 118.It Fl v 119Debug mode. 120This option will make 121.Nm 122run in the foreground, log to 123.Em stderr 124and show verbose messages. 125.El 126.Sh EXAMPLES 127Relay multicast packets in the current network to a unicast address 128(the relay must have a global address in em0): 129.Pp 130.Dl # dhcrelay6 -i em0 2001:db8::1000%em0 131.Pp 132Listen to one subnet and multicast DHCPv6 packets to another 133(requires at least link-local addresses): 134.Pp 135.Dl # dhcrelay6 -i em0 em1 136.Pp 137Relay DHCPv6 packets with Interface-ID (option 18) using the input 138interface as its content: 139.Pp 140.Dl # dhcrelay6 -o -i em0 2001:db8::1000%em0 141.Pp 142Same thing as before but with a custom Interface-ID: 143.Pp 144.Dl # dhcrelay6 -o -I \(dqOpenBSD Router 1\(dq -i em0 2001:db8::1000%em0 145.Pp 146Use Lightweight DHCPv6 Relay Agent (layer 2 relay) in a bridged or 147switched network (no IPv6 address required). 148Only makes sense when em0 and em1 are configured in a 149.Xr bridge 4 , 150since 151.Nm 152needs to drop the original DHCPv6 packets and send modified ones with 153Interface-ID option. 154.Pp 155.Dl # dhcrelay6 -l -i em0 em1 156.Pp 157Identify a segment using Lightweight DHCPv6 Relay Agent (layer 2 relay) 158with a Remote-ID (option 37) instead of an Interface-ID: 159.Pp 160.Dl # dhcrelay6 -l -R \&"OpenBSD Router A\&" -i em0 em1 161.Sh SEE ALSO 162.Xr bridge 4 , 163.Xr dhcrelay 8 164.Sh STANDARDS 165.Rs 166.%A R. Droms 167.%A J. Bound 168.%A B. Volz 169.%A T. Lemon 170.%A C. Perkins 171.%A M. Carney 172.%D July 2003 173.%R RFC 3315 174.%T Dynamic Host Configuration Protocol for IPv6 (DHCPv6) 175.Re 176.Pp 177.Rs 178.%A B. Volz 179.%D August 2006 180.%R RFC 4649 181.%T Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Relay Agent Remote-ID Option 182.Re 183.Pp 184.Rs 185.%A D. Miles 186.%A S. Ooghe 187.%A W. Dec 188.%A S. Krishnan 189.%A A. Kavanagh 190.%D May 2011 191.%R RFC 6221 192.%T Lightweight DHCPv6 Relay Agent 193.Re 194.Sh AUTHORS 195.An -nosplit 196.Xr dhcrelay 8 197was written by 198.An Ted Lemon Aq Mt mellon@fugue.com 199and reworked by 200.An Henning Brauer Aq Mt henning@openbsd.org . 201.Pp 202IPv6 support was implemented by 203.An Rafael Zalamena Aq Mt rzalamena@openbsd.org . 204