idnits 2.17.1 draft-ietf-dhc-relay-id-suboption-07.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** The document seems to lack a License Notice according IETF Trust Provisions of 28 Dec 2009, Section 6.b.i or Provisions of 12 Sep 2009 Section 6.b -- however, there's a paragraph with a matching beginning. Boilerplate error? (You're using the IETF Trust Provisions' Section 6.b License Notice from 12 Feb 2009 rather than one of the newer Notices. See https://trustee.ietf.org/license-info/.) Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (July 7, 2009) is 5379 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'TBA' is mentioned on line 225, but not defined ** Obsolete normative reference: RFC 3315 (Obsoleted by RFC 8415) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) Summary: 3 errors (**), 0 flaws (~~), 2 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 DHC M. Stapp 3 Internet-Draft Cisco Systems, Inc. 4 Intended status: Standards Track July 7, 2009 5 Expires: January 8, 2010 7 The DHCPv4 Relay Agent Identifier Suboption 8 draft-ietf-dhc-relay-id-suboption-07.txt 10 Status of this Memo 12 This Internet-Draft is submitted to IETF in full conformance with the 13 provisions of BCP 78 and BCP 79. 15 Internet-Drafts are working documents of the Internet Engineering 16 Task Force (IETF), its areas, and its working groups. Note that 17 other groups may also distribute working documents as Internet- 18 Drafts. 20 Internet-Drafts are draft documents valid for a maximum of six months 21 and may be updated, replaced, or obsoleted by other documents at any 22 time. It is inappropriate to use Internet-Drafts as reference 23 material or to cite them other than as "work in progress." 25 The list of current Internet-Drafts can be accessed at 26 http://www.ietf.org/ietf/1id-abstracts.txt. 28 The list of Internet-Draft Shadow Directories can be accessed at 29 http://www.ietf.org/shadow.html. 31 This Internet-Draft will expire on January 8, 2010. 33 Copyright Notice 35 Copyright (c) 2009 IETF Trust and the persons identified as the 36 document authors. All rights reserved. 38 This document is subject to BCP 78 and the IETF Trust's Legal 39 Provisions Relating to IETF Documents in effect on the date of 40 publication of this document (http://trustee.ietf.org/license-info). 41 Please review these documents carefully, as they describe your rights 42 and restrictions with respect to this document. 44 Abstract 46 This memo defines a new Relay Agent Identifier suboption for the 47 Dynamic Host Configuration Protocol's (DHCP) Relay Agent Information 48 option. The suboption carries a value that uniquely identifies the 49 relay agent device. The value may be administratively-configured or 50 may be generated by the relay agent. The suboption allows a DHCP 51 relay agent to include the identifier in the DHCP messages it sends. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 56 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 3. Example Use-Cases . . . . . . . . . . . . . . . . . . . . . . . 3 58 3.1. Industrial Ethernet . . . . . . . . . . . . . . . . . . . . 3 59 3.2. Bulk Leasequery . . . . . . . . . . . . . . . . . . . . . . 4 60 4. Suboption Format . . . . . . . . . . . . . . . . . . . . . . . 4 61 5. Relay Identifier Types . . . . . . . . . . . . . . . . . . . . 5 62 6. Generating a Relay Identifier . . . . . . . . . . . . . . . . . 5 63 7. Identifier Stability . . . . . . . . . . . . . . . . . . . . . 5 64 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 65 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 66 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 67 10.1. Normative References . . . . . . . . . . . . . . . . . . . 6 68 10.2. Informative References . . . . . . . . . . . . . . . . . . 7 69 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 71 1. Introduction 73 The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) [RFC2131] 74 provides IP addresses and configuration information for IPv4 clients. 75 It includes a relay agent capability, in which network elements 76 receive broadcast messages from clients and forward them to DHCP 77 servers as unicast messages. In many network environments, relay 78 agents add information to the DHCP messages before forwarding them, 79 using the Relay Agent Information option [RFC3046]. Servers that 80 recognize the relay information option echo it back in their replies. 82 This specification introduces a Relay Agent Identifier suboption for 83 the Relay Information option. The Relay-Id suboption carries a 84 sequence of octets that is intended to identify the relay agent 85 uniquely within the administrative domain. The identifier may be 86 administratively configured: in some networks it may be adequate to 87 assign ASCII strings such as "switch1" and "switch2". Alternatively, 88 the identifier may be generated by the relay agent itself, and we 89 specify use of DUIDs [RFC3315] for this purpose. 91 2. Terminology 93 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 94 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 95 document are to be interpreted as described in [RFC2119]. 97 DHCPv4 terminology is defined in [RFC2131], and the DHCPv4 Relay 98 Agent Information Option in [RFC3046]. DUID terminology is in 99 [RFC3315]. 101 3. Example Use-Cases 103 3.1. Industrial Ethernet 105 DHCP typically identifies clients based on information in their DHCP 106 messages - such as the Client-Identifier option, or the value of the 107 chaddr field. In some networks, however, the location of a client - 108 its point of attachment to the network - is a more useful identifier. 109 In factory-floor networks (commonly called 'Industrial' networks), 110 for example, the role a device plays is often fixed and based on its 111 location. Using manual address configuration is possible (and is 112 common) but it would be beneficial if DHCP configuration could be 113 applied to these networks. 115 One way to provide connection-based identifiers for industrial 116 networks is to have the network elements acting as DHCP relay agents 117 supply information that a DHCP server could use as a client 118 identifier. A straightforward way to form identifier information is 119 to combine something that is unique within the scope of the network 120 element, such as a port/slot value, with something that uniquely 121 identifies that network element, such as a Relay Agent Identifier. 123 3.2. Bulk Leasequery 125 There has been quite a bit of recent interest in extending the DHCP 126 Leasequery protocol [RFC4388] to accommodate some additional 127 situations. There is a recent draft ([draft-kinnear]) proposing a 128 variety of enhancements to the existing Leasequery protocol. The 129 draft describes a use-case where a relay agent queries DHCP servers 130 using the Relay Identifier to retrieve all the leases allocated 131 through the relay device. 133 4. Suboption Format 135 Format of the Relay Agent Identifier suboption: 137 0 1 2 3 138 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 140 |SUBOPT_RELAY_ID| length | type | | 141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 142 . . 143 . identifier (variable) . 144 . . 145 +---------------------------------------------------------------+ 147 Where: 149 SUBOPT_RELAY_ID [TBA] 151 length the number of octets in the suboption 152 (excluding the suboption ID and length fields); 153 the minimum length is two. 155 type a single octet describing the type of 156 identifier that is present. 158 identifier the identifying data. 160 5. Relay Identifier Types 162 For clarity, the suboption specified here includes a type octet that 163 describes the data used in the identifier field. The type value zero 164 is reserved and MUST NOT be used. Two type values are defined here: 165 RELAY_IDENTIFIER_DUID and RELAY_IDENTIFIER_ASCII. 166 RELAY_IDENTIFIER_DUID is used when the identifier field contains a 167 DUID [RFC3315]. Administrators may want to assign human-friendly 168 ASCII identifiers: RELAY_IDENTIFIER_ASCII is used when the identifier 169 field contains an ASCII string. 171 6. Generating a Relay Identifier 173 As described in Section 1, in some situations it may be useful for 174 network devices to generate identifiers themselves. Relay agents who 175 send the Relay Agent Identifier suboption using identifiers that are 176 not administratively-configured MUST be generated following the 177 procedures in the DUID section of [RFC3315]. Relay agents who use 178 generated identifiers SHOULD make the generated value visible to 179 their administrators via their user interface, through a log entry, 180 or through some other mechanism. 182 7. Identifier Stability 184 If the relay identifier is to be meaningful it has to be stable. A 185 relay agent SHOULD use a single identifier type and value 186 consistently. The identifier used by a relay device SHOULD be 187 committed to stable storage, unless the relay device can regenerate 188 the value upon reboot. 190 Implementors should note that the identifier needs to be present in 191 all DHCP message types where its value is being used by the DHCP 192 server. The relay agent may not be able to add the Relay Agent 193 Information option to all messages - such as RENEW messages sent as 194 IP unicasts. In some deployments that might mean that the server has 195 to be willing to continue to associate the relay identifier it has 196 last seen with a lease that is being RENEWed. Other deployments may 197 prefer to use the Server Identifier Override suboption [RFC5107] to 198 permit the relay device to insert the Information option into all 199 relayed messages. 201 Handling situations where a relay agent device is replaced is another 202 aspect of "stability". One of the use-cases for the relay identifier 203 is to permit a server to associate clients' lease bindings with the 204 relay device connected to the clients. If the relay device is 205 replaced, because it has failed or been upgraded, it may be desirable 206 for the new device to continue to provide the same relay identifier 207 as the old device. Implementors should be aware of this possibility, 208 and consider making it possible for administrators to configure the 209 identifier. 211 8. Security Considerations 213 Security issues with the Relay Agent Information option and its use 214 by servers in address assignment are discussed in [RFC3046] and 215 [RFC4030]. Relay agents who send the Relay Agent Identifier 216 suboption SHOULD use the Relay Agent Authentication suboption 217 [RFC4030] to provide integrity protection. 219 9. IANA Considerations 221 We request that IANA assign a new suboption code from the registry of 222 DHCP Agent Sub-Option Codes maintained in 223 http://www.iana.org/assignments/bootp-dhcp-parameters. 225 Relay Agent Identifier Suboption [TBA] 227 We request that IANA establish a new registry of DHCP Relay Agent 228 Identifier Sub-Option Types, to be maintained in 229 http://www.iana.org/assignments/bootp-dhcp-parameters. The 230 Identifier Type is a single octet. The initial values assigned in 231 this document are: 233 Reserved 0 234 RELAY_IDENTIFIER_DUID 1 235 RELAY_IDENTIFIER_ASCII 2 237 Additional Identifier Type values will be allocated and assigned 238 through IETF Review, as defined in [RFC5226]. 240 10. References 242 10.1. Normative References 244 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 245 Requirement Levels", BCP 14, RFC 2119, March 1997. 247 [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", 248 RFC 2131, March 1997. 250 [RFC3046] Patrick, M., "DHCP Relay Agent Information Option", 251 RFC 3046, January 2001. 253 [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., 254 and M. Carney, "Dynamic Host Configuration Protocol for 255 IPv6 (DHCPv6)", RFC 3315, July 2003. 257 [RFC4030] Stapp, M. and T. Lemon, "The Authentication Suboption for 258 the Dynamic Host Configuration Protocol (DHCP) Relay Agent 259 Option", RFC 4030, March 2005. 261 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 262 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 263 May 2008. 265 10.2. Informative References 267 [RFC4388] Woundy, R. and K. Kinnear, "Dynamic Host Configuration 268 Protocol (DHCP) Leasequery", RFC 4388, February 2006. 270 [RFC5107] Johnson, R., Kumarasamy, J., Kinnear, K., and M. Stapp, 271 "DHCP Server Identifier Override Suboption", RFC 5107, 272 February 2008. 274 [draft-kinnear] 275 Kinnear, K., Volz, B., Russell, N., and M. Stapp, "Bulk 276 DHCPv4 Lease Query 277 (draft-kinnear-dhc-dhcpv4-bulk-leasequery-*)", July 2008. 279 Author's Address 281 Mark Stapp 282 Cisco Systems, Inc. 283 1414 Massachusetts Ave. 284 Boxborough, MA 01719 285 USA 287 Phone: +1 978 936 0000 288 Email: mjs@cisco.com