--- 1/draft-ietf-mboned-mcaddrdoc-02.txt 2012-02-09 01:13:57.442671500 +0100 +++ 2/draft-ietf-mboned-mcaddrdoc-03.txt 2012-02-09 01:13:57.462671219 +0100 @@ -1,23 +1,23 @@ Network Working Group S. Venaas Internet-Draft R. Parekh Intended status: Informational G. Van de Velde -Expires: April 27, 2012 cisco Systems +Expires: August 12, 2012 cisco Systems T. Chown University of Southampton M. Eubanks Iformata Communications - October 25, 2011 + February 9, 2012 Multicast Addresses for Documentation - draft-ietf-mboned-mcaddrdoc-02.txt + draft-ietf-mboned-mcaddrdoc-03.txt Abstract This document discusses which multicast addresses should be used for documentation purposes and reserves multicast addresses for such use. Some multicast addresses are derived from AS numbers or unicast addresses. This document also explains how these can be used for documentation purposes. Status of this Memo @@ -28,44 +28,44 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months 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." - This Internet-Draft will expire on April 27, 2012. + This Internet-Draft will expire on August 12, 2012. Copyright Notice - Copyright (c) 2011 IETF Trust and the persons identified as the + Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. IPv4 multicast documentation addresses . . . . . . . . . . . . 4 2.1. Administratively scoped IPv4 multicast addresses . . . . . 4 2.2. GLOP multicast addresses . . . . . . . . . . . . . . . . . 4 - 2.3. Unicast prefix based IPv4 multicast addresses . . . . . . 4 + 2.3. Unicast prefix based IPv4 multicast addresses . . . . . . 5 3. IPv6 multicast documentation addresses . . . . . . . . . . . . 6 3.1. Unicast prefix based IPv6 multicast addresses . . . . . . 6 3.2. Embedded-RP IPv6 multicast addresses . . . . . . . . . . . 6 4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 7. Informative References . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction @@ -85,47 +85,51 @@ reserves multicast addresses for this purpose. There are also some multicast addresses that are derived from AS numbers or unicast addresses. For examples where such addresses are desired, one should derive them from the AS numbers and unicast addresses reserved for documentation purposes. This document also discusses the use of these. 2. IPv4 multicast documentation addresses - The type of multicast addresses most commonly used today, are - addresses used for so-called ASM (Any-Source Multicast). For ASM, - the IPv4 multicast addresses allocated for documentation purposes are - 233.252.0.0 - 233.252.0.255 (233.252.0.0/24). + For Any-Source Multicast (ASM), the IPv4 multicast addresses + allocated for documentation purposes are 233.252.0.0 - 233.252.0.255 + (233.252.0.0/24). - Another type of multicast is SSM (Source-Specific Multicast). For - SSM it is less important which multicast addresses are used, since a - host/application joins a channel identified by both source and group. - Any source addresses used in SSM examples should be unicast addresses - reserved for documentation purposes. There are three unicast address - ranges provided for documentation use in [RFC5737]. The ranges are + For Source-Specific Multicast (SSM) it is less important which + multicast addresses are used, since a host/application joins a + channel identified by both source and group. Any source addresses + used in SSM examples should be unicast addresses reserved for + documentation purposes. There are three unicast address ranges + provided for documentation use in [RFC5737]. The ranges are 192.0.2.0/24, 198.51.100.0/24 and 203.0.113.0/24. Sometimes one wants to give examples where a specific type of address is desired. E.g. for text about multicast scoping, one might want the examples to use addresses that are to be used for administrative scoping. See below for guidance on how to construct specific types of example addresses. 2.1. Administratively scoped IPv4 multicast addresses Administratively scoped IPv4 multicast addresses [RFC2365] are reserved for scoped multicast. They can be used within a site or an organization. Apart from a small set of scope relative addresses, - these addresses are not assigned. There are no specific scoped - addresses available for documentation purposes. Except for examples - detailing the use of scoped multicast, one should avoid using them. + these addresses are not assigned. The high order /24 in every scope + is reserved for relative assignments. A relative assignment is an + integer offset from the highest address in the scope and represents + an IPv4 address. For documentation purposes, the integer offset is + TBD1. This provides one multicast address per scope. + + For example in the Local Scope 239.255.0.0/16, the multicast address + for documentation purposes is 239.255.255.255-TBD1. 2.2. GLOP multicast addresses GLOP [RFC3180] is a method for deriving IPv4 multicast group addresses from 16 bit AS numbers. For examples where GLOP addresses are desired, the addresses should be derived from the AS numbers reserved for documentation use. The 16 bit AS numbers reserved for documentation use in [RFC5398] are 64496 - 64511. By use of [RFC3180], we then get 16 /24 multicast @@ -140,88 +144,92 @@ reserved for documentation purposes, see [RFC5737]. There are three unicast address ranges provided for documentation use in [RFC5737]. The ranges are 192.0.2.0/24, 198.51.100.0/24 and 203.0.113.0/24. Using [RFC6034] this leaves us with the unicast prefix based IPv4 multicast addresses 234.192.0.2, 234.198.51.100 and 234.203.0.113. 3. IPv6 multicast documentation addresses - The type of multicast addresses most commonly used today, are - addresses used for so-called ASM (Any-Source Multicast). For ASM, - the IPv6 multicast addresses allocated for documentation purposes are - TBD. + For Any-Source Multicast (ASM) the IPv6 multicast addresses allocated + for documentation purposes are TBD2. - Another type of multicast is SSM (Source-Specific Multicast). For - SSM it is less important which multicast addresses are used, since a - host/application joins a channel identified by both source and group. - Any source addresses used in SSM examples should be unicast addresses - reserved for documentation purposes. The IPv6 unicast prefix - reserved for documentation purposes is 2001:DB8::/32, see [RFC3849]. + For Source-Specific Multicast (SSM) it is less important which + multicast addresses are used, since a host/application joins a + channel identified by both source and group. Any source addresses + used in SSM examples should be unicast addresses reserved for + documentation purposes. The IPv6 unicast prefix reserved for + documentation purposes is 2001:DB8::/32, see [RFC3849]. Sometimes one wants to give examples where a specific type of address is desired. E.g. for text about multicast scoping, one might want the examples to use addresses that are to be used for administrative scoping. See below for guidance on how to construct specific types of example addresses. 3.1. Unicast prefix based IPv6 multicast addresses IPv6 multicast addresses can be derived from IPv6 unicast prefixes, see [RFC3306]. For examples where this type of addresses is desired, the addresses should be derived from the unicast addresses reserved for documentation purposes. The IPv6 unicast prefix reserved for documentation purposes is 2001: DB8::/32, see [RFC3849]. This allows a wide range of different IPv6 - multicast addresses. Using just the base /32 prefix, one get the + multicast addresses. Using just the base /32 prefix, one gets the IPv6 multicast prefixes FF3X:20:2001:DB8::/64, one for each available scope X. One can also produce longer prefixes from this. Just as an example, one can pick say a /64 prefix 2001:DB8:DEAD:BEEF::/64 which gives the multicast prefixes FF3X:40:2001:DB8:DEAD:BEEF::/96, one for each available scope X. 3.2. Embedded-RP IPv6 multicast addresses There is a type of IPv6 multicast addresses called Embedded-RP addresses where the IPv6 address of a Rendezvous-Point is embedded inside the multicast address, see [RFC3956]. For examples where this type of addresses is desired, the addresses should be derived from - the unicast addresses reserved for documentation purposes, see see + the unicast addresses reserved for documentation purposes, see [RFC3849]. For documentation purposes, the RP address can be any address from the range 2001:DB8::/32 that follows the constraints specified in [RFC3956]. One example address could be 2001:DB8::1. The embedded-RP multicast prefixes might then be FF7X:120:2001:DB8::/96. Another example could be the RP address 2001:DB8:BEEF:FEED::7 which gives the prefixes FF7X:740:2001:DB8:BEEF:FEED::/96. See also the examples in [RFC3956]. 4. Security Considerations The use of specific multicast addresses for documentation purposes has no impact on security. 5. IANA Considerations + IANA is requested to assign a scope relative IPv4 address for + documentation purposes. The string TBD1 in this document should be + replaced by the assigned offset. Also the string 255-TBD1 should be + replaced by the value of 255 minus the assigned offset. These last + two sentences should be deleted before publishing. + IANA is requested to assign "variable scope" IPv6 multicast addresses for documentation purposes. This should be a /96 prefix of the form - FF0X:... The word TBD in this text should be replaced with the + FF0X:... The word TBD2 in this text should be replaced with the assigned prefix, and this sentence should be deleted before publishing. 6. Acknowledgments - The authors thank Roberta Maglione and Leonard Giuliano for providing - comments on this document. + The authors thank Roberta Maglione, Leonard Giuliano and Dave Thaler + for providing comments on this document. 7. Informative References [RFC2365] Meyer, D., "Administratively Scoped IP Multicast", BCP 23, RFC 2365, July 1998. [RFC3180] Meyer, D. and P. Lothberg, "GLOP Addressing in 233/8", BCP 53, RFC 3180, September 2001. [RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6