--- 1/draft-ietf-mpls-tp-ethernet-addressing-04.txt 2013-02-01 21:28:22.536086934 +0100 +++ 2/draft-ietf-mpls-tp-ethernet-addressing-05.txt 2013-02-01 21:28:22.552089251 +0100 @@ -1,20 +1,20 @@ -MPLS D. Frost, Ed. -Internet-Draft S. Bryant, Ed. +MPLS D. Frost +Internet-Draft S. Bryant Intended status: Standards Track Cisco Systems -Expires: June 9, 2013 M. Bocci, Ed. +Expires: August 5, 2013 M. Bocci Alcatel-Lucent - December 6, 2012 + February 1, 2013 MPLS-TP Next-Hop Ethernet Addressing - draft-ietf-mpls-tp-ethernet-addressing-04 + draft-ietf-mpls-tp-ethernet-addressing-05 Abstract The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP) is the set of MPLS protocol functions applicable to the construction and operation of packet-switched transport networks. This document presents considerations for link-layer addressing of Ethernet frames carrying MPLS-TP packets. Status of this Memo @@ -25,25 +25,25 @@ 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 June 9, 2013. + This Internet-Draft will expire on August 5, 2013. Copyright Notice - Copyright (c) 2012 IETF Trust and the persons identified as the + Copyright (c) 2013 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 @@ -65,29 +65,27 @@ functionality is optional in an MPLS-TP network, however, IP-based protocols for Media Access Control (MAC) address learning, such as the Address Resolution Protocol (ARP) [RFC0826] and IP version 6 Neighbor Discovery [RFC4861], may not be available. This document specifies the options for determination and selection of next-hop Ethernet MAC addressing under these circumstances. 1.1. Terminology Term Definition - ------- ------------------------------------------- + ------- --------------------------- ARP Address Resolution Protocol G-ACh Generic Associated Channel - GAL G-ACh Label LSP Label Switched Path LSR Label Switching Router MAC Media Access Control MPLS-TP MPLS Transport Profile - OAM Operations, Administration, and Maintenance Additional definitions and terminology can be found in [RFC5960] and [RFC5654]. 1.2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. @@ -99,21 +97,22 @@ transmitted to the peer node over the link. The problem of determining this address does not arise in IP/MPLS networks because of the presence of the Ethernet Address Resolution Protocol (ARP) [RFC0826] or IP version 6 Neighbor Discovery protocol [RFC4861], which allow the unicast MAC address of the peer device to be learned dynamically. If existing mechanisms are available in an MPLS-TP network to determine the destination unicast MAC addresses of peer nodes -- for example, if the network also happens to be an IP/MPLS network, or if - it implements the procedures in Section 4 of this document -- such + Link Layer Discovery Protocol (LLDP) [LLDP] is in use, or if it + implements the procedures in Section 4 of this document -- such mechanisms SHOULD be used. The remainder of this section discusses the available options when this is not the case. Each node MAY be statically configured with the MAC address of its peer. Note however that static MAC address configuration can present an administrative burden and lead to operational problems. For example, replacement of an Ethernet interface to resolve a hardware fault when this approach is used requires that the peer node be manually reconfigured with the new MAC address. This is especially problematic if the peer is operated by another provider. @@ -170,136 +169,180 @@ The G-ACh Advertisement Protocol (GAP) [I-D.ietf-mpls-gach-adv] provides a simple means of informing listeners on a link of the sender's capabilities and configuration. When used for this purpose on an Ethernet link, GAP messages are multicast to the address 01-00- 5e-80-00-0d. If these messages contain the unicast MAC address of the sender, then listeners can learn this address and use it in the future when transmitting frames containing MPLS-TP packets. Since the GAP does not rely on IP, this provides a means of unicast MAC discovery for MPLS-TP nodes without IP support. - This document defines a new GAP application, "Ethernet Interface - Parameters", to support the advertisement of Ethernet-specific + This document defines a new GAP application "Ethernet Interface + Parameters" (TBD1), to support the advertisement of Ethernet-specific parameters associated with the sending interface. The following - Type-Length-Value (TLV) objects are defined for this application: + Type-Length-Value (TLV) objects are defined for this application; the + TLV format is as defined in [I-D.ietf-mpls-gach-adv]: - Source MAC Address: The Value of this object is a 48-bit Ethernet - unicast MAC address in canonical form [RFC2469] assigned to one of - the interfaces of the sender that is connected to this data link. + Source MAC Address (type = 0, length = 8): The Value of this + object is an EUI-64 [EUI-64] unicast MAC address assigned to one + of the interfaces of the sender that is connected to this data + link. The IEEE-defined mapping from 48-bit MAC addresses to + EUI-64 form is used. - MTU: The Value of this object is a 32-bit unsigned integer encoded - in network byte order that specifies the maximum transmission unit - size of the sending interface, in octets. + MTU (type = 1, length = 4): The Value of this object is a 32-bit + unsigned integer encoded in network byte order that specifies the + maximum transmission unit size of the sending interface, in + octets. -5. Security Considerations + Where MAC address learning occurs by some other means, this TLV group + MAY be used to advertise only the MTU. If multiple adverisements are + made for the the same parameter, use of these advertisments is + undefined. + + In the event of the persistent loss of the GAP messages, the + receiving node MUST assume that it is now connected to a node that + does not support these advertisements and must behave as configured + for this eventuality. + +5. Manageability Considerations + + The values sent and received by this protocol MUST be made accessible + for inspection by network operators, and where local configuration is + updated by the received information, it MUST be clear why the + configured value has been changed. The advertised information SHOULD + be persistent across restarts. Received advertisements MUST be + discarded across restarts. If the received values change, the new + values MUST be used and the change made visible to the network + operators. + +6. Security Considerations The use of broadcast or multicast Ethernet destination MAC addresses for frames carrying MPLS-TP data packets can potentially result in such frames being distributed to devices other than the intended destination node or nodes when the Ethernet link is not point-to- point. The operator SHOULD take care to ensure that MPLS-TP nodes are aware of the Ethernet link type (point-to-point or multipoint). In the case of multipoint links, the operator SHOULD either ensure that no devices are attached to the link that are not authorized to receive the frames, or take steps to mitigate the possibility of excessive frame distribution, for example by configuring the Ethernet switch to appropriately restrict the delivery of multicast frames to authorized ports. -6. IANA Considerations + An attacker could disrupt communications by modifying the Source MAC + Address or the MTU values, however this is mitigated by the use of + cryptographic authetication as described in [I-D.ietf-mpls-gach-adv] + which also describes other considerations applicable to the GAP + protocol. Visibility into the contents of either of the TLVs could + provide information that is useful for an attacker. This is best + addressed by physical security of the links. -6.1. Ethernet Multicast Address Allocation +7. IANA Considerations + +7.1. Ethernet Multicast Address Allocation IANA has allocated an Ethernet multicast address from the "IANA Multicast 48-bit MAC Addresses" address block in the "Ethernet Numbers" registry for use by MPLS-TP LSRs over point-to-point links as described in Section 2. The allocated address is - 01-00-5E-90-00-00. + 01-00-5E-90-00-00. IANA is requested to update the reference to + point to the RFC number assigned to this document. -6.2. G-ACh Advertisement Protocol Allocation +7.2. G-ACh Advertisement Protocol Allocation IANA is requested to allocate a new Application ID in the "G-ACh Advertisement Protocol Applications" registry [I-D.ietf-mpls-gach-adv] (currently located in the "Pseudowire Name Spaces (PWE3)"), as follows: Application ID Description Reference - -------------- ----------------------------- ------------ - 0x0001 Ethernet Interface Parameters (this draft) + --------------------------- ---------------------------- ------------ + TBD1 to be assigned by IANA Ethernet Interface (this draft) + Parameters -6.3. Creation of Ethernet Interface Parameters Registry +7.3. Creation of Ethernet Interface Parameters Registry IANA is requested to create a new registry, "G-ACh Advertisement Protocol: Ethernet Interface Parameters" within the "Pseudowire Name Spaces (PWE3)" with fields and initial allocations as follows: Type Name Type ID Reference ------------------ ------- ------------ Source MAC Address 0 (this draft) MTU 1 (this draft) The range of the Type ID field is 0 - 255. The allocation policy for this registry is IETF Review. -7. References +8. Acknowledgements -7.1. Normative References + We thank Adrian Farrel for his valuable review comments on this + document. + +9. References + +9.1. Normative References + + [EUI-64] "[EUI64] IEEE, "Guidelines for 64-bit Global Identifier + (EUI-64) Registration Authority", http:// + standards.ieee.org/regauth/oui/tutorials/EUI64.html, March + 1997.". [I-D.ietf-mpls-gach-adv] Frost, D., Bryant, S., and M. Bocci, "MPLS Generic Associated Channel (G-ACh) Advertisement Protocol", - draft-ietf-mpls-gach-adv-03 (work in progress), - October 2012. + draft-ietf-mpls-gach-adv-04 (work in progress), + December 2012. + + [LLDP] "IEEE, "Station and Media Access Control Connectivity + Discovery (802.1AB)", September 2009.". [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. - [RFC2469] Narten, T. and C. Burton, "A Caution On The Canonical - Ordering Of Link-Layer Addresses", RFC 2469, - December 1998. - [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, January 2001. [RFC5332] Eckert, T., Rosen, E., Aggarwal, R., and Y. Rekhter, "MPLS Multicast Encapsulations", RFC 5332, August 2008. [RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, September 2009. [RFC5960] Frost, D., Bryant, S., and M. Bocci, "MPLS Transport Profile Data Plane Architecture", RFC 5960, August 2010. -7.2. Informative References +9.2. Informative References [RFC0826] Plummer, D., "Ethernet Address Resolution Protocol: Or converting network protocol addresses to 48.bit Ethernet address for transmission on Ethernet hardware", STD 37, RFC 826, November 1982. [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007. [RFC5921] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A Framework for MPLS in Transport Networks", RFC 5921, July 2010. Authors' Addresses - Dan Frost (editor) + Dan Frost Cisco Systems Email: danfrost@cisco.com - Stewart Bryant (editor) + Stewart Bryant Cisco Systems Email: stbryant@cisco.com - Matthew Bocci (editor) + Matthew Bocci Alcatel-Lucent Email: matthew.bocci@alcatel-lucent.com