CCAMP Working Group Zafar Ali Hassan Sheikh Internet Draft Cisco Systems, Inc. Tomohiro Otani KDDI R&D Laboratories, Inc. Hidetsugu Sugiyama Juniper Networks Intended status: BCP November 18, 2007 Expires: May 2008 Address Resolution for GMPLS controlled PSC Ethernet Interfaces draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.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 other groups may also distribute working documents as Internet-Drafts. 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." 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. Copyright Notice Copyright (C) The IETF Trust (2007). Z. Ali Expires May 18, 2008 [Page 1] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt Abstract This document outlines some interoperability issues observed with the use of ARP over GMPLS controlled Ethernet router-to- router (PSC) interfaces transiting from a non-Ethernet core, e.g., FSC or LSC core. The document also recommends some procedures to address these issues. The aim of this document is to facilitate and ensure better interworking of GMPLS- capable Label Switching Routers (LSRs), based on experience gained in interoperability testing. Conventions used in this document In examples, "C:" and "S:" indicate lines sent by the client and server respectively. 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 RFC-2119 [RFC2119]. Table of Contents 1. Terminology...............................................2 2. Introduction..............................................3 3. Address to use for ARP Resolution.........................5 4. Security Considerations...................................5 5. IANA Considerations.......................................5 6. References................................................6 6.1. Normative References.................................6 6.2. Informative References...............................6 7. Author's Addresses........................................6 8. Intellectual Property Statement...........................7 9. Copyright Statement.......................................7 1. Terminology The control plane address refers to the address assigned to the TE Links. This address is used to advertise TE link in the TE topology. The data plane address refers to the address assigned to the Ethernet data link or the address assigned to the GMPLS tunnel interface. This address is used at PSC (packet switching capable) layer for forwarding traffic over the GMPLS LSP. The Z. Ali, et al Expires May 18, 2008 [Page 2] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt terms the data plane address and the GMPLS tunnel address are used synonymously. 2. Introduction This draft addresses the scenario where edge routers are connected via a non-Ethernet switch capable GMPLS core, e.g., FSC or LSC core [RFC3471], [RFC3473]. Furthermore, the interfaces between the router and the optical device (OXC) are Ethernet, and considered as point-to-point. The TE links can be numbered or unnumbered. Similarly, data plane address can be numbered or unnumbered. Furthermore, the LSP end-points may or may not be in the same subnets. When an LSP Path is established between the Ingress and Egress LSRs, Ethernet interface at the two LSRs comes up. Unlike POS links where a L2 adjacency resolution is not required, the Ethernet links require that the ARP be resolved (also known as Layer 2 MAC address) before any forwarding works on this link. Specifically, before a GMPLS LSP with Ethernet end-point can forward any IP traffic, MAC address of the remote router needs to be resolved. The remote MAC address learning is the same procedure used in ARP resolution to be able to map an ip address to a MAC address on an Ethernet Data Link. End-point MAC address needs to be re-learned once the ARP cache entries time-out, or every time the Ethernet Data Link path taken by the GMPLS LSP changes (e.g., due to re-routing or re-optimization). This introduces latency that is at least equal to the round trip delay. Such latency adds to the traffic switchover delay and consequently traffic loss for 1:1 protected LSP without extra traffic, or when LSP route changes due to re-routing (restoration) or re-optimization, etc. Interoperability issues in learning end-point MAC address in the Ethernet Data Link using ARP are also found among vendors at various Interoperability events/ testing efforts. This is because different vendors use different IP address for ARP resolution. Some LSR vendor uses the control plane address of the TE link at the end-point, while others adapt to use data plane address on the Ethernet Data Link for ARP resolution. When GMPLS tunnel is protected, i.e., it has working and protecting LSP-es, the ARP requested for a given Ethernet IF address should resolve ARP for the physical Ethernet interfaces along the path of working and protecting LSP. Issue associated with ARP latency and traffic loss for 1:1 protected LSP without extra traffic, or when LSP route changes due to Z. Ali, et al Expires May 18, 2008 [Page 3] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt re-routing (restoration) or re-optimization, etc. could not be addressed. This document provides some recommendations for the use of the MAC addresses resolution (ARP resolution) for a GMPLS LSP. In the following, we provide reason behind recommendations provided in this document. Consider following scenarios. 1. When numbered TE links are used but the LSP end-points are in different subnets: In this case disjoint subnets are used with numbered TE links between the Ingress LSR and the Optical node, and the Egress LSR and the optical node. In this situation we really have no way of resolving ARP using the addresses of the underlying TE link, without using static ARP entries. The issue is that the subnets are different so the ARP request received by Egress LSR from Ingress LSR will be rejected as it is not known to Egress LSR, and vice versa. This issue can be resolved when the ARP request uses Ethernet data link address. This is because the Ethernet data link is point-to-point logical link with IPV4 addresses in the same subnet. 2. When the Ethernet data link is numbered but the TE links are Unnumbered and Ingress LSR does not have loopback address used by Egress LSR in its forwarding database, and vice versa. An example of such scenario is the case when optical and packet TE links are flooded with different IGP instances. In this case, we are again faced with the same issue of L2 ARP adjacency resolution between Ingress and Egress LSR. Egress LSR will reject the ARP request for Ingress LSR as it will not find the unnumbered address (used by Ingress LSR) in its forwarding database. This issue can also be resolve by using Ethernet data link address in the ARP request. 3. Unnumbered for Ethernet data link: If the Ethernet data link is unnumbered then the ARP resolution needs to be done using donor interface IP address such as Loopback address (/32). However, OSPFv2 adjacency is not established between non-network nodes Z. Ali, et al Expires May 18, 2008 [Page 4] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt (/32) in Ethernet. In this case, the Ethernet data link established with GMPLS tunnel would require the router to support OSPFv2/ISIS adjacency in non-network data plane segment. 4. GMPLS Protection Case: The use of the protected Ethernet data link along with GMPLS LSP for ARP resolution can also extended to the case where the GMPLS tunnel is provided end-to-end 1:1 protection i.e. a working LSP and a protected LSP of the GMPLS tunnel are typically using different physical interfaces (different MAC addresses) with different TE Link. This issue can be resolved by using the same IP address and same MAC address for ARP resolution over working and protecting interfaces. The use of this implementation along with the creation of such mapping would also eliminate the problem of ARP cache timeout on the protected link; and hence can address the above- mentioned ARP latency issue related to protection case. 3. Address to use for ARP Resolution An LSR SHOULD use data plane address on Ethernet data link for ARP request. For protected point-to-point interfaces, an LSR SHOULD resolve APR for two or more physical interfaces using the same IP address and same MAC address (this is to address ARP Latency issue mentioned-above). In the case of unnumbered interface in Ethernet data link associate with GMPLS tunnel, ARP resolution SHOULD use donor interface such as Loopback interface (/32) and OSPFv2 SHOULD establish adjacency in the non-network IP segment. 4. Security Considerations This document does not introduce new security issues. 5. IANA Considerations This document does not require any IANA consideration. Z. Ali, et al Expires May 18, 2008 [Page 5] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt 6. References 6.1. Normative References [RFC2119] "Key words for use in RFCs to Indicate Requirement Levels", S. Bradner, http://tools.ietf.org/html/rfc2119. 6.2. Informative References [RFC3471] Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description, RFC 3471, L. Berger, et al, January 2003. [RFC3473] "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, L. Berger, et al, January 2003. 7. Author's Addresses Zafar Ali Cisco Systems Inc. 2000 Innovation Dr., Kanata, Ontario, K2K 3E8 Canada. Phone: (613) 889-6158 Email: zali@cisco.com Hassan Sheikh Cisco Systems Inc. 2000 Innovation Dr., Kanata, Ontario, K2K 3E8 Canada. Phone: (613) 254-3356 Email: hassans@cisco.com Tomohiro Otani KDDI R&D Laboratories, Inc. 2-1-15 Ohara Fujimino-shi Saitama, 356-8502. Japan Phone: +81-49-278-7357 Email: otani@kddilabs.jp Hidetsugu Sugiyama Juniper Networks Email: hidet@juniper.net Z. Ali, et al Expires May 18, 2008 [Page 6] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt 8. Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on- line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. 9. Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Z. Ali, et al Expires May 18, 2008 [Page 7] draft-ali-arp-over-gmpls-controlled-ethernet-psc-i-05.txt Z. Ali, et al Expires May 18, 2008 [Page 8]