--- 1/draft-ietf-dhc-bcmc-options-02.txt 2006-02-04 23:01:38.000000000 +0100 +++ 2/draft-ietf-dhc-bcmc-options-03.txt 2006-02-04 23:01:38.000000000 +0100 @@ -1,21 +1,21 @@ Network Working Group K. Chowdhury Internet-Draft Starent Networks -Expires: December 31, 2005 P. Yegani +Expires: February 2, 2006 P. Yegani Cisco Systems L. Madour Ericsson - June 29, 2005 + August 1, 2005 DHCP Options for Broadcast and Multicast Control Servers - draft-ietf-dhc-bcmc-options-02.txt + draft-ietf-dhc-bcmc-options-03.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -26,21 +26,21 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on December 31, 2005. + This Internet-Draft will expire on February 2, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document defines new options to discover the Broadcast and Multicast Service (BCMCS) controller in an IP network. BCMCS is being developed for 3rd generation (3G) cellular telephone networks. @@ -58,21 +58,21 @@ 4. Broadcast & Multicast Service Controller Options . . . . . . . 6 4.1 Broadcast & Multicast Service Controller Domain Name list for DHCPv4 . . . . . . . . . . . . . . . . . . . . . 6 4.2 Broadcast & Multicast Service Controller Domain Name List Option for DHCPv6 . . . . . . . . . . . . . . . . . . 7 4.3 Broadcast & Multicast Service Controller IPv4 address option for DHCPv4 . . . . . . . . . . . . . . . . . . . . 7 4.4 Broadcast & Multicast Service Controller IPv6 Address Option for DHCPv6 . . . . . . . . . . . . . . . . . . . . 8 4.5 Consideration for Client Operation . . . . . . . . . . . . 8 - 4.6 Consideration for Server Operation . . . . . . . . . . . . 9 + 4.6 Consideration for Server Operation . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 8. Normative References . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 14 1. Motivation Dynamic Host Configuration Protocol [RFC2131] and [RFC3315] can be @@ -175,47 +175,40 @@ The general format of the BCMCS Controller Domain list option for DHCPv4 is as follows: Code Len FQDN(s) of BCMCS Controller +-----+-----+-----+-----+-----+-----+-----+-- | TBD1| n | s1 | s2 | s3 | s4 | s5 | ... +-----+-----+-----+-----+-----+-----+-----+-- The option MAY contain multiple domain names, but these domain names SHOULD be used to construct SRV lookups as specified in [BCMCS], - rather than querying for different A records. The client MUST try - the records in the order listed, applying the mechanism described in - [BCMCS] for each entry. The client only resolves the subsequent - domain names if attempts to contact the first one failed or yielded - no common transport protocols between the client and the BCMCS - controller or denote a domain that is administratively prohibited by - client's policy. - - The use of multiple domain names is not meant to replace the SRV - records, but rather to allow a single DHCPv4 server to indicate the - BCMCS controllers in the wireless access provider's network. + rather than querying for different A records. The client can try any + or ALL of the domain names to construct the SRV lookups. The list of + domain names MAY conatin the domain name of the access provider and + it's partner networks that also offer broadcast and multicast + service. If the length of the domain list exceeds the maximum permissible length within a single option (254 octets), then the domain list MUST - be represented in the DHCPv4 message as specified in [RFC3396] . - - An example case when two controller domain names, example.com and + be represented in the DHCPv4 message as specified in [RFC3396] . An + example case when two controller domain names, example.com and example.net are returned will be: +----+----+----+----+----+----+----+----+----+----+----+ |TBD1| 26 | 7 | 'e'| 'x'| 'a'| 'm'| 'p'| 'l'| 'e'| 3 | +----+----+----+----+----+----+----+----+----+----+----+ +----+----+----+----+----+----+----+----+----+----+----+ - |'c' | 'o'| 'm'| 0 | 'e'| 'x'| 'a'| 'm'| 'p'| 'l'| 'e'| + |'c' |'o'| 'm'| 0 | 7 | 'e'| 'x'| 'a'| 'm'| 'p'| 'l'| +----+----+----+----+----+----+----+----+----+----+----+ +----+----+----+----+----+----+ - | 3 | 'n'| 'e'| 't'| 0 | 7 | + |'e' | 3 | 'n'| 'e'| 't'| 0 | +----+----+----+----+----+----+ 4.2 Broadcast & Multicast Service Controller Domain Name List Option for DHCPv6 The semantics and content of the DHCPv6 encoding of this option is exactly the same as the encoding described in the previous section, other than necessary differences between the way options are encoded in DHCPv4 and DHCPv6. @@ -230,21 +223,21 @@ | BCMCS Control Server Domain Name List | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code: OPTION_BCMCS_SERVER_D (TBD2). option-length: Length of the 'BCMCS Control Server Domain Name List' field in octets; variable. BCMCS Control Server Domain Name List: Identical content as in - Section 4.1 + Section 4.1 (except the Code and Len fields). 4.3 Broadcast & Multicast Service Controller IPv4 address option for DHCPv4 The Length byte (Len) is followed by a list of IPv4 addresses indicating BCMCS controller IPv4 addresses. The BCMCS controllers MUST be listed in order of preference. Its minimum length is 4, and the length MUST be a multiple of 4. The DHCPv4 option for this encoding has the following format: @@ -283,23 +276,23 @@ field in octets; variable. 4.5 Consideration for Client Operation For DHCPv6, a client MAY request either or both of the BCMCS Controller Domain Name List and the IPv6 Address options in the Options Request Option (ORO) as described in [RFC3315]. If a client receives both the BCMCS Controller Domain Name List and IPv6 Address options, it SHOULD use the Domain Name List option. In - this case, the client MAY use the BCMCS Controller IPv6 Address - option only if the servers in the BCMCS Controller Domain Name List - can not be resolved or reached. + this case, the client SHOULD NOT use the BCMCS Controller IPv6 + Address option unless the servers in the BCMCS Controller Domain Name + List can not be resolved or reached. 4.6 Consideration for Server Operation A server MAY send a client either the BCMCS Controller Domain Name List Option or the BCMCS Controller IPv6 Address/IPv4 Address options if the server is configured to do so. In case of DHCPv6, If a client requests both options and the server is configured with both types of information, the server MAY send the client only one of these options if it is configured to do so. In @@ -325,70 +318,68 @@ Client sends in ORO Domain Name List IPv6 Address List __________________________________________________________________ Neither option SHOULD MAY Domain Name List MUST MAY IPv6 Address MAY MUST Both options SHOULD MAY 5. Security Considerations - The security considerations in the base DHCP spec [RFC2131] applies. - An attacker may change information of the BCMCS Controller in packets - that are in-tranist from DHCP server to the MN, if integrity - protection is not in place. In that event, the user of the Broadcast - & Multicast service may be diverted to a rogue BCMCS controller. + This document does not introduce any new security concerns beyond + those specified in the basic DHCP [RFC2131] and DHCPv6 [RFC3315] + specifications. In the absence of message integrity protection for + these options, an attacker could modify the option values to + frustrate or divert requests for broadcast service. 6. IANA Considerations The following option codes for Broadcast & Multicast Service Controller option must be assigned by IANA: 1. The BCMCS Controller Domain Name list (section 4.1) has been assigned a value of TBD1 from the DHCPv4 option space. 2. The BCMCS Controller Domain Name list (section 4.2) has been assigned a value of TBD2 from the DHCPv6 option space, and a name of OPTION_BCMCS_SERVER_D. 3. The BCMCS Controller IPv4 address option (section 4.3) has been assigned a value of TBD3 from the DHCPv4 option space. 4. The BCMCS Controller IPv6 address option (section 4.4) has been assigned a value of TBD4 from the DHCPv6 option space, and a name of OPTION_BCMCS_SERVER_A. - The DHCP options should be registered in - http://www.iana.org/assignments/bootp-dhcp-extensions - - The DHCPv6 options should be registered in - http://www.iana.org/assignments/dhcpv6-parameters - 7. Acknowledgements Thanks to the following indivduals for their review and constructive comments during the development of this document: AC Mahendran, Jun Wang, Raymond Hsu, Jayshree Bharatia, Ralph Droms, - Ted Lemon, Margaret Wasserman, and Thomas Narten. + Ted Lemon, Margaret Wasserman, Thomas Narten, Elwyn Davies, Pekka + Savola, and Bert Wijnen. 8. Normative References [BCMCS] 3GPP2, www.3gpp2.org, ftp://ftp.3gpp2.org/TSGX/Projects/X.P0022 2ndV&V.zip, "X.S0022, Broadcast and Multicast Service in cdma2000 Wireless IP Network. (pending publication)", December 2004. [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3396] Lemon, T. and S. Cheshire, "Encoding Long Options in the Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396, November 2002.