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diff --git a/sbin/dhclient/dhcp-options.5 b/sbin/dhclient/dhcp-options.5 new file mode 100644 index 00000000000..72d978353ef --- /dev/null +++ b/sbin/dhclient/dhcp-options.5 @@ -0,0 +1,592 @@ +.\" $OpenBSD: dhcp-options.5,v 1.1 2004/01/18 01:26:20 deraadt Exp $ +.\" +.\" Copyright (c) 1995, 1996, 1997, 1998 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 January 1, 1995 +.Dt DHCP-OPTIONS 5 +.Os +.Sh NAME +.Nm dhcp-options +.Nd Dynamic Host Configuration Protocol options +.Sh DESCRIPTION +The Dynamic Host Configuration protocol allows the client to receive +.Ic options +from the DHCP server describing the network configuration and various +services that are available on the network. +When configuring +.Xr dhcpd 8 +or +.Xr dhclient 8 , +options must often be declared. +The syntax for declaring options, and the names and formats of the options +that can be declared, are documented here. +.Sh REFERENCE: OPTION STATEMENTS +DHCP +.Ic option +statements always start with the +.Ic option +keyword, followed by an option name, followed by option data. +The option names and data formats are described below. +It is not necessary to exhaustively specify all DHCP options \- +only those options which are needed by clients must be specified. +.Pp +Option data comes in a variety of formats, as defined below: +.Pp +The +.Ar ip-address +data type can be entered either as an explicit IP address +(e.g., 239.254.197.10) or as a domain name (e.g., haagen.isc.org). +A domain name must resolve to a single IP address. +.Pp +The +.Ar int32 +data type specifies a signed 32-bit integer. +The +.Ar uint32 +data type specifies an unsigned 32-bit integer. +The +.Ar int16 +and +.Ar uint16 +data types specify signed and unsigned 16-bit integers. +The +.Ar int8 +and +.Ar uint8 +data types specify signed and unsigned 8-bit integers. +Unsigned 8-bit integers are also sometimes referred to as octets. +.Pp +The +.Ar string +data type specifies an +.Tn NVT +.Pq Network Virtual Terminal +.Tn ASCII +string, which must be enclosed in double quotes \- for example, +to specify a domain-name option, the syntax would be +.Pp +.Dl option domain-name \&"isc.org\&"; +.Pp +The +.Ar flag +data type specifies a boolean value. +Booleans can be either true or false +(or on or off, if that makes more sense to you). +.Pp +The +.Ar data-string +data type specifies either an +.Tn NVT ASCII +string enclosed in double quotes, or a series of octets specified in +hexadecimal, separated by colons. +For example: +.Pp +.Dl option dhcp-client-identifier \&"CLIENT-FOO\&"; +or +.Dl option dhcp-client-identifier 43:4c:49:45:54:2d:46:4f:4f; +.Pp +The documentation for the various options mentioned below is taken +from the IETF draft document on DHCP options, RFC 2132. +Options which are not listed by name may be defined by the name +.Pf option\- Ns Ar nnn , +where +.Ar nnn +is the decimal number of the option code. +These options may be followed either by a string, enclosed in quotes, or by +a series of octets, expressed as two-digit hexadecimal numbers separated +by colons. +For example: +.Pp +.Bd -literal -offset indent +option option-133 "my-option-133-text"; +option option-129 1:54:c9:2b:47; +.Ed +.Pp +Because +.Xr dhcpd 8 +does not know the format of these undefined option codes, +no checking is done to ensure the correctness of the entered data. +.Pp +The standard options are: +.Bl -tag -width Ds +.Ss RFC 1497 Vendor Extensions +.It Ic option subnet-mask Ar ip-address ; +The +.Ic subnet-mask +option specifies the client's subnet mask as per RFC 950. +If no subnet-mask option is provided anywhere in scope, as a last resort +.Xr dhcpd 8 +will use the subnet mask from the subnet declaration for the network on +which an address is being assigned. +However, +.Em any +subnet-mask option declaration that is in scope for the address being +assigned will override the subnet mask specified in the subnet declaration. +.It Ic option time-offset Ar int32 ; +The +.Ic time-offset +option specifies the offset of the client's subnet in seconds from +Coordinated Universal Time (UTC). +.It Xo +.Ic option routers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic routers +option specifies a list of IP addresses for routers on the client's subnet. +Routers should be listed in order of preference. +.It Xo +.Ic option time-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic time-server +option specifies a list of RFC 868 time servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option ien116-name-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic ien116-name-servers +option specifies a list of IEN 116 name servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option domain-name-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic domain-name-servers +option specifies a list of Domain Name System (STD 13, RFC 1035) name servers +available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option log-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic log-servers +option specifies a list of MIT-LCS UDP log servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option cookie-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic cookie-servers +option specifies a list of RFC 865 cookie servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option lpr-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic lpr-servers +option specifies a list of RFC 1179 line printer servers available to the +client. +Servers should be listed in order of preference. +.It Xo +.Ic option impress-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic impress-servers +option specifies a list of Imagen Impress servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option resource-location-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of RFC 887 Resource Location servers available +to the client. +Servers should be listed in order of preference. +.It Ic option host-name Ar string ; +This option specifies the name of the client. +The name may or may not be qualified with the local domain name +(it is preferable to use the +.Ic domain-name +option to specify the domain name). +See RFC 1035 for character set restrictions. +.It Ic option boot-size Ar uint16 ; +This option specifies the length in 512-octet blocks of the default +boot image for the client. +.It Ic option merit-dump Ar string ; +This option specifies the pathname of a file to which the client's +core image should be dumped in the event the client crashes. +The path is formatted as a character string consisting of characters from +the +.Tn NVT ASCII +character set. +.It Ic option domain-name Ar string ; +This option specifies the domain name that the client should use when +resolving hostnames via the Domain Name System. +.It Ic option swap-server Ar ip-address ; +This specifies the IP address of the client's swap server. +.It Ic option root-path Ar string ; +This option specifies the pathname that contains the client's root disk. +The path is formatted as a character string consisting of characters from +the +.Tn NVT ASCII +character set. +.El +.Ss IP Layer Parameters per Host +.Bl -tag -width Ds +.It Ic option ip-forwarding Ar flag ; +This option specifies whether the client should configure its IP layer +for packet forwarding. +A value of 0 means disable IP forwarding, and a value of 1 means enable +IP forwarding. +.It Ic option non-local-source-routing Ar flag ; +This option specifies whether the client should configure its IP +layer to allow forwarding of datagrams with non-local source routes +(see Section 3.3.5 of [4] for a discussion of this topic). +A value of 0 means disallow forwarding of such datagrams, and a value of 1 +means allow forwarding. +.It Xo +.Ic option policy-filter Ar ip-address ip-address +.Oo , Ar ip-address ip-address ... Oc ; +.Xc +This option specifies policy filters for non-local source routing. +The filters consist of a list of IP addresses and masks which specify +destination/mask pairs with which to filter incoming source routes. +.Pp +Any source-routed datagram whose next-hop address does not match one +of the filters should be discarded by the client. +.Pp +See STD 3 (RFC 1122) for further information. +.It Ic option max-dgram-reassembly Ar uint16 ; +This option specifies the maximum size datagram that the client should be +prepared to reassemble. +The minimum legal value is 576. +.It Ic option default-ip-ttl Ar uint8 ; +This option specifies the default time-to-live that the client should +use on outgoing datagrams. +.It Ic option path-mtu-aging-timeout Ar uint32 ; +This option specifies the timeout (in seconds) to use when aging Path +MTU values discovered by the mechanism defined in RFC 1191. +.It Xo +.Ic option path-mtu-plateau-table Ar uint16 +.Oo , Ar uint16 ... Oc ; +.Xc +This option specifies a table of MTU sizes to use when performing +Path MTU Discovery as defined in RFC 1191. +The table is formatted as a list of 16-bit unsigned integers, +ordered from smallest to largest. +The minimum MTU value cannot be smaller than 68. +.El +.Ss IP Layer Parameters per Interface +.Bl -tag -width Ds +.It Ic option interface-mtu Ar uint16 ; +This option specifies the MTU to use on this interface. +The minimum legal value for the MTU is 68. +.It Ic option all-subnets-local Ar flag ; +This option specifies whether or not the client may assume that all subnets +of the IP network to which the client is connected use the same MTU as the +subnet of that network to which the client is directly connected. +A value of 1 indicates that all subnets share the same MTU. +A value of 0 means that the client should assume that some subnets of the +directly connected network may have smaller MTUs. +.It Ic option broadcast-address Ar ip-address ; +This option specifies the broadcast address in use on the client's subnet. +Legal values for broadcast addresses are specified in section 3.2.1.3 of +STD 3 (RFC 1122). +.It Ic option perform-mask-discovery Ar flag ; +This option specifies whether or not the client should perform subnet mask +discovery using ICMP. +A value of 0 indicates that the client should not perform mask discovery. +A value of 1 means that the client should perform mask discovery. +.It Ic option mask-supplier Ar flag ; +This option specifies whether or not the client should respond to subnet mask +requests using ICMP. +A value of 0 indicates that the client should not respond. +A value of 1 means that the client should respond. +.It Ic option router-discovery Ar flag ; +This option specifies whether or not the client should solicit routers using +the Router Discovery mechanism defined in RFC 1256. +A value of 0 indicates that the client should not perform router discovery. +A value of 1 means that the client should perform router discovery. +.It Ic option router-solicitation-address Ar ip-address ; +This option specifies the address to which the client should transmit +router solicitation requests. +.It Xo +.Ic option static-routes Ar ip-address ip-address +.Oo , Ar ip-address ip-address ... Oc ; +.Xc +This option specifies a list of static routes that the client should +install in its routing cache. +If multiple routes to the same destination are specified, they are listed +in descending order of priority. +.Pp +The routes consist of a list of IP address pairs. +The first address is the destination address, +and the second address is the router for the destination. +.Pp +The default route (0.0.0.0) is an illegal destination for a static route. +To specify the default route, use the +.Ic routers +option. +.El +.Ss Link Layer Parameters per Interface +.Bl -tag -width Ds +.It Ic option trailer-encapsulation Ar flag ; +This option specifies whether or not the client should negotiate the +use of trailers (RFC 893 [14]) when using the ARP protocol. +A value of 0 indicates that the client should not attempt to use trailers. +A value of 1 means that the client should attempt to use trailers. +.It Ic option arp-cache-timeout Ar uint32 ; +This option specifies the timeout in seconds for ARP cache entries. +.It Ic option ieee802-3-encapsulation Ar flag ; +This option specifies whether or not the client should use Ethernet +Version 2 (RFC 894) or IEEE 802.3 (RFC 1042) encapsulation if the +interface is an Ethernet. +A value of 0 indicates that the client should use RFC 894 encapsulation. +A value of 1 means that the client should use RFC 1042 encapsulation. +.El +.Ss TCP Parameters +.Bl -tag -width Ds +.It Ic option default-tcp-ttl Ar uint8 ; +This option specifies the default TTL that the client should use when +sending TCP segments. +The minimum value is 1. +.It Ic option tcp-keepalive-interval Ar uint32 ; +This option specifies the interval (in seconds) that the client TCP +should wait before sending a keepalive message on a TCP connection. +The time is specified as a 32-bit unsigned integer. +A value of zero indicates that the client should not generate keepalive +messages on connections unless specifically requested by an application. +.It Ic option tcp-keepalive-garbage Ar flag ; +This option specifies whether or not the client should send TCP keepalive +messages with an octet of garbage for compatibility with older implementations. +A value of 0 indicates that a garbage octet should not be sent. +A value of 1 indicates that a garbage octet should be sent. +.El +.Ss Application and Service Parameters +.Bl -tag -width Ds +.It Ic option nis-domain Ar string ; +This option specifies the name of the client's NIS (Sun Network Information +Services) domain. +The domain is formatted as a character string consisting of characters +from the +.Tn NVT ASCII +character set. +.It Xo +.Ic option nis-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of IP addresses indicating NIS servers +available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option ntp-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of IP addresses indicating NTP (RFC 1035) +servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option netbios-name-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The NetBIOS name server (NBNS) option specifies a list of RFC 1001/1002 +NBNS name servers listed in order of preference. +NetBIOS Name Service is currently more commonly referred to as WINS. +WINS servers can be specified using the +.Ic netbios-name-servers +option. +.It Xo +.Ic option netbios-dd-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The NetBIOS datagram distribution server (NBDD) option specifies a +list of RFC 1001/1002 NBDD servers listed in order of preference. +.It Ic option netbios-node-type Ar uint8 ; +The NetBIOS node type option allows NetBIOS over TCP/IP clients which +are configurable to be configured as described in RFC 1001/1002. +The value is specified as a single octet which identifies the client type. +.Pp +Possible node types are: +.Pp +.Bl -tag -width Ds +.It 1 +B-node: Broadcast - no WINS +.It 2 +P-node: Peer - WINS only +.It 4 +M-node: Mixed - broadcast, then WINS +.It 8 +H-node: Hybrid - WINS, then broadcast +.El +.It Ic option netbios-scope Ar string ; +The NetBIOS scope option specifies the NetBIOS over TCP/IP scope +parameter for the client as specified in RFC 1001/1002. +See RFC 1001, RFC 1002, and RFC 1035 for character-set restrictions. +.It Xo +.Ic option font-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of X Window System Font servers available +to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option x-display-manager Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of systems that are running the X Window +System Display Manager and are available to the client. +Addresses should be listed in order of preference. +.It Ic option dhcp-client-identifier Ar data-string ; +This option can be used to specify a DHCP client identifier in a +host declaration, so that +.Xr dhcpd 8 +can find the host record by matching against the client identifier. +.It Ic option nisplus-domain Ar string ; +This option specifies the name of the client's NIS+ domain. +The domain is formatted as a character string consisting of characters +from the +.Tn NVT ASCII +character set. +.It Xo +.Ic option nisplus-servers Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of IP addresses indicating NIS+ servers +available to the client. +Servers should be listed in order of preference. +.It Ic option tftp-server-name Ar string ; +This option is used to identify a TFTP server and, if supported by the +client, should have the same effect as the +.Ic server-name +declaration. +BOOTP clients are unlikely to support this option. +Some DHCP clients will support it, and others actually require it. +.It Ic option bootfile-name Ar string ; +This option is used to identify a bootstrap file. +If supported by the client, it should have the same effect as the +.Ic filename +declaration. +BOOTP clients are unlikely to support this option. +Some DHCP clients will support it, and others actually require it. +.It Xo +.Ic option mobile-ip-home-agent Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +This option specifies a list of IP addresses indicating mobile IP +home agents available to the client. +Agents should be listed in order of preference, although normally there +will be only one such agent. +.It Xo +.Ic option smtp-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic smtp-server +option specifies a list of SMTP servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option pop-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic pop-server +option specifies a list of POP3 servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option nntp-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic nntp-server +option specifies a list of NNTP servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option www-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic www-server +option specifies a list of WWW servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option finger-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic finger-server +option specifies a list of +.Xr finger 1 +servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option irc-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic irc-server +option specifies a list of IRC servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option streettalk-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The +.Ic streettalk-server +option specifies a list of StreetTalk servers available to the client. +Servers should be listed in order of preference. +.It Xo +.Ic option streettalk-directory-assistance-server Ar ip-address +.Oo , Ar ip-address ... Oc ; +.Xc +The StreetTalk Directory Assistance (STDA) server option specifies a +list of STDA servers available to the client. +Servers should be listed in order of preference. +.El +.Sh SEE ALSO +.Xr dhclient.conf 5 , +.Xr dhcpd.conf 5 , +.Xr dhcpd.leases 5 , +.Xr dhclient 8 , +.Xr dhcpd 8 +.Pp +RFC 2131, RFC 2132. +.Sh AUTHORS +.Xr dhcpd 8 +was written by +.An Ted Lemon Aq mellon@vix.com +under a contract with Vixie Labs. +Funding for this project was provided by the Internet Software Corporation. +Information about the Internet Software Consortium can be found at +.Pa http://www.isc.org/isc . |