1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
.\" $OpenBSD: dhcrelay6.8,v 1.4 2023/03/02 17:09:54 jmc Exp $
.\"
.\" Copyright (c) 1997 The Internet Software Consortium.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of The Internet Software Consortium nor the names
.\" of its contributors may be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
.\" DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" This software has been written for the Internet Software Consortium
.\" by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
.\" Enterprises. To learn more about the Internet Software Consortium,
.\" see ``http://www.isc.org/isc''. To learn more about Vixie
.\" Enterprises, see ``http://www.vix.com''.
.\"
.Dd $Mdocdate: March 2 2023 $
.Dt DHCRELAY6 8
.Os
.Sh NAME
.Nm dhcrelay6
.Nd Dynamic Host Configuration Protocol for IPv6 (DHCPv6) relay agent
.Sh SYNOPSIS
.Nm
.Op Fl dlov
.Op Fl E Ar enterprise-number
.Op Fl I Ar interface-id
.Op Fl R Ar remote-id
.Fl i Ar interface
.Ar destination ...
.Sh DESCRIPTION
The
.Nm
utility provides a means for relaying DHCPv6 requests from a subnet to
which no DHCP server is directly connected to one or more DHCPv6 servers
on other subnets.
.Pp
.Nm
listens for DHCPv6 requests on a given interface.
When a query is received,
.Nm
forwards it to the list of DHCP destinations specified on the command
line.
When a reply is received, it is sent on the network from whence the
original request came.
.Pp
The
.Ar destination
might be an address followed by a `%' and an interface name,
or just an interface name (e.g. "2001:db8::1%em0" or "em1").
When no address is specified,
.Nm
will use multicast on the specified interface.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl d
Do not daemonize.
If this option is specified,
.Nm
will run in the foreground and log to
.Em stderr .
.It Fl E Ar enterprise-number
Choose the
.Ar enterprise-number
that will be used by the Remote-ID option (this only has effect when using
.Fl R ) .
.It Fl I Ar interface-id
The
.Ar interface-id
relay agent information option value that
.Nm
should use on relayed packets.
If this option is not specified, it will use the interface name by
default.
.Pp
Avoid using this option when using Lightweight DHCPv6 Relay Mode
(layer 2 relay), otherwise
.Nm
will always send replies back to the client interface, which will break
networks with multiple DHCPv6 layer 2 relay agents.
.It Fl i Ar interface
The name of the network interface
which will receive client DHCPv6 requests.
For layer 3 mode at least one IPv6 local, site or global address has to
be configured on this interface.
.It Fl l
Use the Lightweight DHCPv6 Relay Agent mode (layer 2 relaying).
.It Fl o
Add the Interface-ID option.
This option is activated by default when using layer 2 relaying.
.It Fl R Ar remote-id
Enable and add the specified Relay Agent
.Ar remote-id
to identify this relay segment.
.It Fl v
Debug mode.
This option will make
.Nm
run in the foreground, log to
.Em stderr
and show verbose messages.
.El
.Sh EXAMPLES
Relay multicast packets in the current network to a unicast address
(the relay must have a global address in em0):
.Pp
.Dl # dhcrelay6 -i em0 2001:db8::1000%em0
.Pp
Listen to one subnet and multicast DHCPv6 packets to another
(requires at least link-local addresses):
.Pp
.Dl # dhcrelay6 -i em0 em1
.Pp
Relay DHCPv6 packets with Interface-ID (option 18) using the input
interface as its content:
.Pp
.Dl # dhcrelay6 -o -i em0 2001:db8::1000%em0
.Pp
Same thing as before but with a custom Interface-ID:
.Pp
.Dl # dhcrelay6 -o -I \(dqOpenBSD Router 1\(dq -i em0 2001:db8::1000%em0
.Pp
Use Lightweight DHCPv6 Relay Agent (layer 2 relay) in a bridged or
switched network (no IPv6 address required).
Only makes sense when em0 and em1 are configured in a
.Xr bridge 4 ,
since
.Nm
needs to drop the original DHCPv6 packets and send modified ones with
Interface-ID option.
.Pp
.Dl # dhcrelay6 -l -i em0 em1
.Pp
Identify a segment using Lightweight DHCPv6 Relay Agent (layer 2 relay)
with a Remote-ID (option 37) instead of an Interface-ID:
.Pp
.Dl # dhcrelay6 -l -R \&"OpenBSD Router A\&" -i em0 em1
.Sh SEE ALSO
.Xr bridge 4 ,
.Xr dhcrelay 8
.Sh STANDARDS
.Rs
.%A R. Droms
.%A J. Bound
.%A B. Volz
.%A T. Lemon
.%A C. Perkins
.%A M. Carney
.%D July 2003
.%R RFC 3315
.%T Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
.Re
.Pp
.Rs
.%A B. Volz
.%D August 2006
.%R RFC 4649
.%T Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Relay Agent Remote-ID Option
.Re
.Pp
.Rs
.%A D. Miles
.%A S. Ooghe
.%A W. Dec
.%A S. Krishnan
.%A A. Kavanagh
.%D May 2011
.%R RFC 6221
.%T Lightweight DHCPv6 Relay Agent
.Re
.Sh AUTHORS
.An -nosplit
.Xr dhcrelay 8
was written by
.An Ted Lemon Aq Mt mellon@fugue.com
and reworked by
.An Henning Brauer Aq Mt henning@openbsd.org .
.Pp
IPv6 support was implemented by
.An Rafael Zalamena Aq Mt rzalamena@openbsd.org .
|
