Benchmarking Methodology for Network Interconnect Devices
RFC 2544
Document | Type |
RFC
- Informational
(March 1999)
Errata
Obsoletes RFC 1944
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Authors | |||
Last updated | 2020-01-21 | ||
RFC stream | Legacy stream | ||
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RFC 2544
Internet Engineering Task Force N. Elkins Internet-Draft Inside Products, Inc. Intended status: Standards Track M. Ackermann Expires: 28 August 2024 BCBS Michigan A. Deshpande NITK Surathkal/Google T. Pecorella University of Florence A. Rashid Politecnico di Bari 25 February 2024 IPv6 Performance and Diagnostic Metrics Version 2 (PDMv2) Destination Option draft-ietf-ippm-encrypted-pdmv2-06 Abstract RFC8250 describes an optional Destination Option (DO) header embedded in each packet to provide sequence numbers and timing information as a basis for measurements. As this data is sent in clear-text, this may create an opportunity for malicious actors to get information for subsequent attacks. This document defines PDMv2 which has a lightweight handshake (registration procedure) and encryption to secure this data. Additional performance metrics which may be of use are also defined. About This Document This note is to be removed before publishing as an RFC. The latest revision of this draft can be found at https://ameyand.github.io/PDMv2/draft-elkins-ippm-encrypted- pdmv2.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-ietf-ippm-encrypted-pdmv2/. Discussion of this document takes place on the IP Performance Measurement Working Group mailing list (mailto:ippm@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/ippm/. Subscribe at https://www.ietf.org/mailman/listinfo/ippm/. Source for this draft and an issue tracker can be found at https://github.com/ameyand/PDMv2. Elkins, et al. Expires 28 August 2024 [Page 1] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 https://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 28 August 2024. Copyright Notice Copyright (c) 2024 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 (https://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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions used in this document . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Client - Server Negotiation . . . . . . . . . . . . . . . 5 4.2. Implementation Guidelines . . . . . . . . . . . . . . . . 6 4.2.1. Use Case 1: Server does not understand PDM or PDMv2 . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2.2. Use Case 2: Server does not allow PDM or PDMv2 . . . 6 5. Security Goals . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Security Goals for Confidentiality . . . . . . . . . . . 7 5.2. Security Goals for Integrity . . . . . . . . . . . . . . 7 5.3. Security Goals for Authentication . . . . . . . . . . . . 8 5.4. Cryptographic Algorithm . . . . . . . . . . . . . . . . . 8 6. PDMv2 Destination Options . . . . . . . . . . . . . . . . . . 8 Elkins, et al. Expires 28 August 2024 [Page 2] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 6.1. Destinations Option Header . . . . . . . . . . . . . . . 8 6.2. Metrics information in PDMv2 . . . . . . . . . . . . . . 9 6.3. PDMv2 Layout . . . . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 7.1. Limited Threat Model . . . . . . . . . . . . . . . . . . 13 7.1.1. Passive attacks with unencrypted PDMv2 . . . . . . . 13 7.1.2. Passive attacks with encrypted PDMv2 . . . . . . . . 14 7.1.3. Active attacks with unencrypted PDMv2 . . . . . . . . 14 7.1.4. Active attacks with encrypted PDMv2 . . . . . . . . . 16 7.2. Topological considerations . . . . . . . . . . . . . . . 16 7.3. Further mitigations . . . . . . . . . . . . . . . . . . . 16 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 17 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 11.1. Normative References . . . . . . . . . . . . . . . . . . 18 11.2. Informative References . . . . . . . . . . . . . . . . . 19 Appendix A. Sample Implementation of Registration . . . . . . . 19 A.1. Overall summary . . . . . . . . . . . . . . . . . . . . . 19 A.2. High level flow . . . . . . . . . . . . . . . . . . . . . 19 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 20 Appendix C. Open Issues . . . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20 1. Introduction The current PDM is an IPv6 Destination Options header which provides information based on the metrics like Round-trip delay and Server delay. This information helps to measure the Quality of Service (QoS) and to assist in diagnostics. However, there are potential risks involved transmitting PDM data during a diagnostics session. PDM metrics can help an attacker understand about the type of machine and its processing capabilities. Inferring from the PDM data, the attack can launch a timing attack. For example, if a cryptographic protocol is used, a timing attack may be launched against the keying material to obtain the secret. Along with this, PDM does not provide integrity. It is possible for a Machine-In-The-Middle (MITM) node to modify PDM headers leading to incorrect conclusions. For example, during the debugging process using PDM header, it can mislead the person showing there are no unusual server delays. PDMv2 is an IPv6 Destination Options Extension Header which adds confidentiality, integrity and authentication to PDM. Elkins, et al. Expires 28 August 2024 [Page 3] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 The procedures specified in RFC8250 for header placement, implementation, security considerations and so on continue to apply for PDMv2. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Terminology * Endpoint Node: Creates cryptographic keys in collaboration with a partner. * Client: An Endpoint Node which initiates a session with a listening port on another Endpoint Node and sends PDM data. * Server: An Endpoint Node which has a listening port and sends PDM data to another Endpoint Node. Note: a client may act as a server (have listening ports). * Public and Private Keys: A pair of keys that is used in asymmetric cryptography. If one is used for encryption, the other is used for decryption. Private Keys are kept hidden by the source of the key pair generator, but Public Key is known to everyone. pkX (Public Key) and skX (Private Key). Where X can be, any client or any server. * Pre-shared Key (PSK): A symmetric key. Uniformly random bitstring, shared between any Client or any Server or a key shared between an entity that forms client-server relationship. This could happen through an out-of band mechanism: e.g., a physical meeting or use of another protocol. * Session Key: A temporary key which acts as a symmetric key for the whole session. 4. Protocol Flow The protocol will proceed in 2 steps. Step 1: Creation of cryptographic secrets between Server and Client. This includes the creation of pkX and skX. Elkins, et al. Expires 28 August 2024 [Page 4] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 Step 2: PDM data flow between Client and Server. These steps MAY be in the same session or in separate sessions. That is, the cryptographic secrets MAY be created beforehand and used in the PDM data flow at the time of the "real" data session. After-the-fact (or real-time) data analysis of PDM flow may occur by network diagnosticians or network devices. The definition of how this is done is out of scope for this document. 4.1. Client - Server Negotiation The two entities exchange a set of data to ensure the respective identities. This could be done via a TLS or other session. The exact nature of the identity verification is out-of-scope for this document. They use Hybrid Public-Key Encryption scheme (HPKE) Key Encryption Mechanism (KEM) to negotiate a "SharedSecret". Each Client and Server derive a "SessionTemporaryKey" by using HPKE Key Derivation Function (KDF), using the following inputs: * The "SharedSecret". * The 5-tuple (SrcIP, SrcPort, DstIP, DstPort, Protocol) of the communication. * An Epoch. The Epoch SHOULD be initialized to zero. A change in the Epoch indicates that the SessionTemporaryKey has been rotated. When the Epoch rolls over, the SharedSecret SHOULD be re-negotiated. The Epoch MUST be incremented when the Packet Sequence Number (PSN) This Packet (PSNTP) is rolled over. It MAY be incremented earlier, depending on the implementation and the security considerations. The sender MUST NOT create two packets with identical PSNTP and Epoch. The SessionTemporaryKey using a KDF with the following inputs: * SrcIP, SrcPort, DstIP, DstPort, Protocol, SharedSecret, Epoch. Elkins, et al. Expires 28 August 2024 [Page 5] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 4.2. Implementation Guidelines How should a network administrator decide whether a client should use PDM, unencrypted PDMv2, or encrypted PDMv2? This decision is a network policy issue. The administrator must be aware that PDM or unencrypted PDMv2 might expose too much information to malicious parties. That said, if the network administrator decides that taking such a risk within their network is acceptable, then they should make the decision that is appropriate for their network. Alternatively, the network administrator might choose to create a policy that prohibits the use of PDM or unencrypted PDMv2 on their network. The implementation SHOULD provide a way for the network administrator to enforce such a policy. The server and client implementations SHOULD support PDM, unencrypted PDMv2, and encrypted PDMv2. If a client chooses a certain mechanism (e.g., PDM), the server MAY respond with the same mechanism, unless the network administrator has selected a policy that only allows certain mechanisms on their network. 4.2.1. Use Case 1: Server does not understand PDM or PDMv2 If a client sends a packet with PDM or PDMv2 and the server does not have code which understands the header, the packet is processed according to the Option Type which is defined in RFC8250 and is in accordance with RFC8200. The Option Type identifiers is coded to skip over this option and continue processing the header. 4.2.2. Use Case 2: Server does not allow PDM or PDMv2 If a client sends a packet with PDM and the network policy is to only allow encrypted or unencrypted PDMv2, then the PDM / PDMv2 header MUST be ignored and processing continue normally. The server SHOULD log such occurrences but MUST apply rate limiting to any such logs. The implementor should be aware that logging or returning of error messages can be used in a Denial of Service reflector attack. An attacker might send many packets with PDM / PDMv2 and cause the receiver to experience resource exhaustion. The routers involved may have implemented filtering as per [RFC9288] on filtering of IPv6 extension headers which may impact the receipt of PDM / PDMv2. The organization which manages the network within Elkins, et al. Expires 28 August 2024 [Page 6] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 which PDM / PDMv2 is sent should take care that the filtering of extension headers is done correctly so that the desired effect is obtained. 5. Security Goals As discussed in the introduction, PDM data can represent a serious data leakage in presence of a malicious actor. In particular, the sequence numbers included in the PDM header allows correlating the traffic flows, and the timing data can highlight the operational limits of a server to a malicious actor. Moreover, forging PDM headers can lead to unnecessary, unwanted, or dangerous operational choices, e.g., to restore an apparently degraded Quality of Service (QoS). Due to this, it is important that the confidentiality and integrity of the PDM headers is maintained. PDM headers can be encrypted and authenticated using the methods discussed in Section 5.4, thus ensuring confidentiality and integrity. However, if PDM is used in a scenario where the integrity and confidentiality is already ensured by other means, they can be transmitted without encryption or authentication. This includes, but is not limited to, the following cases: a) PDM is used over an already encrypted medium (For example VPN tunnels). b) PDM is used in a link-local scenario. c) PDM is used in a corporate network where there are security measures strong enough to consider the presence of a malicious actor a negligible risk. 5.1. Security Goals for Confidentiality PDM data MUST be kept confidential between the intended parties, which includes (but is not limited to) the two entities exchanging PDM data, and any legitimate party with the proper rights to access such data. 5.2. Security Goals for Integrity An implementation SHOULD attempt to detect if PDM data is forged or modified by a malicious entity. In other terms, the implementation should attempt to detect if a malicious entity has generated a valid PDM header impersonating an endpoint or modified a valid PDM header. RFC 2544 Benchmarking Methodology March 1999 +------------+ | | +------------| tester |<-------------+ | | | | | +------------+ | | | | +------------+ | | | | | +----------->| DUT |--------------+ | | +------------+ Figure 1 +--------+ +------------+ +----------+ | | | | | | | sender |-------->| DUT |--------->| receiver | | | | | | | +--------+ +------------+ +----------+ Figure 2 6.1 Test set up for multiple media types Two different setups could be used to test a DUT which is used in real-world networks to connect networks of differing media type, local Ethernet to a backbone FDDI ring for example. The tester could support both media types in which case the set up shown in Figure 1 would be used. Two identical DUTs are used in the other test set up. (see Figure 3) In many cases this set up may more accurately simulate the real world. For example, connecting two LANs together with a WAN link or high speed backbone. This set up would not be as good at simulating a system where clients on a Ethernet LAN were interacting with a server on an FDDI backbone. +-----------+ | | +---------------------| tester |<---------------------+ | | | | | +-----------+ | | | | +----------+ +----------+ | | | | | | | +------->| DUT 1 |-------------->| DUT 2 |---------+ | | | | +----------+ +----------+ Figure 3 Bradner & McQuaid Informational [Page 4] RFC 2544 Benchmarking Methodology March 1999 7. DUT set up Before starting to perform the tests, the DUT to be tested MUST be configured following the instructions provided to the user. Specifically, it is expected that all of the supported protocols will be configured and enabled during this set up (See Appendix A). It is expected that all of the tests will be run without changing the configuration or setup of the DUT in any way other than that required to do the specific test. For example, it is not acceptable to change the size of frame handling buffers between tests of frame handling rates or to disable all but one transport protocol when testing the throughput of that protocol. It is necessary to modify the configuration when starting a test to determine the effect of filters on throughput, but the only change MUST be to enable the specific filter. The DUT set up SHOULD include the normally recommended routing update intervals and keep alive frequency. The specific version of the software and the exact DUT configuration, including what functions are disabled, used during the tests MUST be included as part of the report of the results. 8. Frame formats The formats of the test frames to use for TCP/IP over Ethernet are shown in Appendix C: Test Frame Formats. These exact frame formats SHOULD be used in the tests described in this document for this protocol/media combination and that these frames will be used as a template for testing other protocol/media combinations. The specific formats that are used to define the test frames for a particular test series MUST be included in the report of the results. 9. Frame sizes All of the described tests SHOULD be performed at a number of frame sizes. Specifically, the sizes SHOULD include the maximum and minimum legitimate sizes for the protocol under test on the media under test and enough sizes in between to be able to get a full characterization of the DUT performance. Except where noted, at least five frame sizes SHOULD be tested for each test condition. Theoretically the minimum size UDP Echo request frame would consist of an IP header (minimum length 20 octets), a UDP header (8 octets) and whatever MAC level header is required by the media in use. The theoretical maximum frame size is determined by the size of the length field in the IP header. In almost all cases the actual maximum and minimum sizes are determined by the limitations of the media. Bradner & McQuaid Informational [Page 5] RFC 2544 Benchmarking Methodology March 1999 In theory it would be ideal to distribute the frame sizes in a way that would evenly distribute the theoretical frame rates. These recommendations incorporate this theory but specify frame sizes which are easy to understand and remember. In addition, many of the same frame sizes are specified on each of the media types to allow for easy performance comparisons. Note: The inclusion of an unrealistically small frame size on some of the media types (i.e. with little or no space for data) is to help characterize the per-frame processing overhead of the DUT. 9.1 Frame sizes to be used on Ethernet 64, 128, 256, 512, 1024, 1280, 1518 These sizes include the maximum and minimum frame sizes permitted by the Ethernet standard and a selection of sizes between these extremes with a finer granularity for the smaller frame sizes and higher frame rates. 9.2 Frame sizes to be used on 4Mb and 16Mb token ring 54, 64, 128, 256, 1024, 1518, 2048, 4472 The frame size recommendations for token ring assume that there is no RIF field in the frames of routed protocols. A RIF field would be present in any direct source route bridge performance test. The minimum size frame for UDP on token ring is 54 octets. The maximum size of 4472 octets is recommended for 16Mb token ring instead of the theoretical size of 17.9Kb because of the size limitations imposed by many token ring interfaces. The reminder of the sizes are selected to permit direct comparisons with other types of media. An IP (i.e. not UDP) frame may be used in addition if a higher data rate is desired, in which case the minimum frame size is 46 octets. 9.3 Frame sizes to be used on FDDI 54, 64, 128, 256, 1024, 1518, 2048, 4472 The minimum size frame for UDP on FDDI is 53 octets, the minimum size of 54 is recommended to allow direct comparison to token ring performance. The maximum size of 4472 is recommended instead of the theoretical maximum size of 4500 octets to permit the same type of comparison. An IP (i.e. not UDP) frame may be used in addition if a higher data rate is desired, in which case the minimum frame size is 45 octets. Bradner & McQuaid Informational [Page 6] RFC 2544 Benchmarking Methodology March 1999 9.4 Frame sizes in the presence of disparate MTUs When the interconnect DUT supports connecting links with disparate MTUs, the frame sizes for the link with the *larger* MTU SHOULD be used, up to the limit of the protocol being tested. If the interconnect DUT does not support the fragmenting of frames in the presence of MTU mismatch, the forwarding rate for that frame size shall be reported as zero. For example, the test of IP forwarding with a bridge or router that joins FDDI and Ethernet should use the frame sizes of FDDI when going from the FDDI to the Ethernet link. If the bridge does not support IP fragmentation, the forwarding rate for those frames too large for Ethernet should be reported as zero. 10. Verifying received frames The test equipment SHOULD discard any frames received during a test run that are not actual forwarded test frames. For example, keep- alive and routing update frames SHOULD NOT be included in the count of received frames. In any case, the test equipment SHOULD verify the length of the received frames and check that they match the expected length. Preferably, the test equipment SHOULD include sequence numbers in the transmitted frames and check for these numbers on the received frames. If this is done, the reported results SHOULD include in addition to the number of frames dropped, the number of frames that were received out of order, the number of duplicate frames received and the number of gaps in the received frame numbering sequence. This functionality is required for some of the described tests. 11. Modifiers It might be useful to know the DUT performance under a number of conditions; some of these conditions are noted below. The reported results SHOULD include as many of these conditions as the test equipment is able to generate. The suite of tests SHOULD be first run without any modifying conditions and then repeated under each of the conditions separately. To preserve the ability to compare the results of these tests any frames that are required to generate the modifying conditions (management queries for example) will be included in the same data stream as the normal test frames in place of one of the test frames and not be supplied to the DUT on a separate network port. Bradner & McQuaid Informational [Page 7] RFC 2544 Benchmarking Methodology March 1999 11.1 Broadcast frames In most router designs special processing is required when frames addressed to the hardware broadcast address are received. In bridges (or in bridge mode on routers) these broadcast frames must be flooded to a number of ports. The stream of test frames SHOULD be augmented with 1% frames addressed to the hardware broadcast address. The frames sent to the broadcast address should be of a type that the router will not need to process. The aim of this test is to determine if there is any effect on the forwarding rate of the other data in the stream. The specific frames that should be used are included in the test frame format document. The broadcast frames SHOULD be evenly distributed throughout the data stream, for example, every 100th frame. The same test SHOULD be performed on bridge-like DUTs but in this case the broadcast packets will be processed and flooded to all outputs. It is understood that a level of broadcast frames of 1% is much higher than many networks experience but, as in drug toxicity evaluations, the higher level is required to be able to gage the effect which would otherwise often fall within the normal variability of the system performance. Due to design factors some test equipment will not be able to generate a level of alternate frames this low. In these cases the percentage SHOULD be as small as the equipment can provide and that the actual level be described in the report of the test results. 11.2 Management frames Most data networks now make use of management protocols such as SNMP. In many environments there can be a number of management stations sending queries to the same DUT at the same time. The stream of test frames SHOULD be augmented with one management query as the first frame sent each second during the duration of the trial. The result of the query must fit into one response frame. The response frame SHOULD be verified by the test equipment. One example of the specific query frame that should be used is shown in Appendix C. 11.3 Routing update frames The processing of dynamic routing protocol updates could have a significant impact on the ability of a router to forward data frames. The stream of test frames SHOULD be augmented with one routing update frame transmitted as the first frame transmitted during the trial. Bradner & McQuaid Informational [Page 8] RFC 2544 Benchmarking Methodology March 1999 Routing update frames SHOULD be sent at the rate specified in Appendix C for the specific routing protocol being used in the test. Two routing update frames are defined in Appendix C for the TCP/IP over Ethernet example. The routing frames are designed to change the routing to a number of networks that are not involved in the forwarding of the test data. The first frame sets the routing table state to "A", the second one changes the state to "B". The frames MUST be alternated during the trial. The test SHOULD verify that the routing update was processed by the DUT. 11.4 Filters Filters are added to routers and bridges to selectively inhibit the forwarding of frames that would normally be forwarded. This is usually done to implement security controls on the data that is accepted between one area and another. Different products have different capabilities to implement filters. The DUT SHOULD be first configured to add one filter condition and the tests performed. This filter SHOULD permit the forwarding of the test data stream. In routers this filter SHOULD be of the form: forward input_protocol_address to output_protocol_address In bridges the filter SHOULD be of the form: forward destination_hardware_address The DUT SHOULD be then reconfigured to implement a total of 25 filters. The first 24 of these filters SHOULD be of the form: block input_protocol_address to output_protocol_address The 24 input and output protocol addresses SHOULD not be any that are represented in the test data stream. The last filter SHOULD permit the forwarding of the test data stream. By "first" and "last" we mean to ensure that in the second case, 25 conditions must be checked before the data frames will match the conditions that permit the forwarding of the frame. Of course, if the DUT reorders the filters or does not use a linear scan of the filter rules the effect of the sequence in which the filters are input is properly lost. The exact filters configuration command lines used SHOULD be included with the report of the results. Bradner & McQuaid Informational [Page 9] RFC 2544 Benchmarking Methodology March 1999 11.4.1 Filter Addresses Two sets of filter addresses are required, one for the single filter case and one for the 25 filter case. The single filter case should permit traffic from IP address 198.18.1.2 to IP address 198.19.65.2 and deny all other traffic. The 25 filter case should follow the following sequence. deny aa.ba.1.1 to aa.ba.100.1 deny aa.ba.2.2 to aa.ba.101.2 deny aa.ba.3.3 to aa.ba.103.3 ... deny aa.ba.12.12 to aa.ba.112.12 allow aa.bc.1.2 to aa.bc.65.1 deny aa.ba.13.13 to aa.ba.113.13 deny aa.ba.14.14 to aa.ba.114.14 ... deny aa.ba.24.24 to aa.ba.124.24 deny all else All previous filter conditions should be cleared from the router before this sequence is entered. The sequence is selected to test to see if the router sorts the filter conditions or accepts them in the order that they were entered. Both of these procedures will result in a greater impact on performance than will some form of hash coding. 12. Protocol addresses It is easier to implement these tests using a single logical stream of data, with one source protocol address and one destination protocol address, and for some conditions like the filters described above, a practical requirement. Networks in the real world are not limited to single streams of data. The test suite SHOULD be first run with a single protocol (or hardware for bridge tests) source and destination address pair. The tests SHOULD then be repeated with using a random destination address. While testing routers the addresses SHOULD be random and uniformly distributed over a range of 256 networks and random and uniformly distributed over the full MAC range for bridges. The specific address ranges to use for IP are shown in Appendix C. Bradner & McQuaid Informational [Page 10] RFC 2544 Benchmarking Methodology March 1999 13. Route Set Up It is not reasonable that all of the routing information necessary to forward the test stream, especially in the multiple address case, will be manually set up. At the start of each trial a routing update MUST be sent to the DUT. This routing update MUST include all of the network addresses that will be required for the trial. All of the addresses SHOULD resolve to the same "next-hop". Normally this will be the address of the receiving side of the test equipment. This routing update will have to be repeated at the interval required by the routing protocol being used. An example of the format and repetition interval of the update frames is given in Appendix C. 14. Bidirectional traffic Normal network activity is not all in a single direction. To test the bidirectional performance of a DUT, the test series SHOULD be run with the same data rate being offered from each direction. The sum of the data rates should not exceed the theoretical limit for the media. 15. Single stream path The full suite of tests SHOULD be run along with whatever modifier conditions that are relevant using a single input and output network port on the DUT. If the internal design of the DUT has multiple distinct pathways, for example, multiple interface cards each with multiple network ports, then all possible types of pathways SHOULD be tested separately. 16. Multi-port Many current router and bridge products provide many network ports in the same module. In performing these tests first half of the ports are designated as "input ports" and half are designated as "output ports". These ports SHOULD be evenly distributed across the DUT architecture. For example if a DUT has two interface cards each of which has four ports, two ports on each interface card are designated as input and two are designated as output. The specified tests are run using the same data rate being offered to each of the input ports. The addresses in the input data streams SHOULD be set so that a frame will be directed to each of the output ports in sequence so that all "output" ports will get an even distribution of packets from this input. The same configuration MAY be used to perform a bidirectional multi-stream test. In this case all of the ports are considered both input and output ports and each data stream MUST consist of frames addressed to all of the other ports. Bradner & McQuaid Informational [Page 11] RFC 2544 Benchmarking Methodology March 1999 Consider the following 6 port DUT: -------------- ---------| in A out X|-------- ---------| in B out Y|-------- ---------| in C out Z|-------- -------------- The addressing of the data streams for each of the inputs SHOULD be: stream sent to input A: packet to out X, packet to out Y, packet to out Z stream sent to input B: packet to out X, packet to out Y, packet to out Z stream sent to input C packet to out X, packet to out Y, packet to out Z Note that these streams each follow the same sequence so that 3 packets will arrive at output X at the same time, then 3 packets at Y, then 3 packets at Z. This procedure ensures that, as in the real world, the DUT will have to deal with multiple packets addressed to the same output at the same time. 17. Multiple protocols This document does not address the issue of testing the effects of a mixed protocol environment other than to suggest that if such tests are wanted then frames SHOULD be distributed between all of the test protocols. The distribution MAY approximate the conditions on the network in which the DUT would be used. 18. Multiple frame sizes This document does not address the issue of testing the effects of a mixed frame size environment other than to suggest that if such tests are wanted then frames SHOULD be distributed between all of the listed sizes for the protocol under test. The distribution MAY approximate the conditions on the network in which the DUT would be used. The authors do not have any idea how the results of such a test would be interpreted other than to directly compare multiple DUTs in some very specific simulated network. 19. Testing performance beyond a single DUT. In the performance testing of a single DUT, the paradigm can be described as applying some input to a DUT and monitoring the output. The results of which can be used to form a basis of characterization of that device under those test conditions. Bradner & McQuaid Informational [Page 12] RFC 2544 Benchmarking Methodology March 1999 This model is useful when the test input and output are homogenous (e.g., 64-byte IP, 802.3 frames into the DUT; 64 byte IP, 802.3 frames out), or the method of test can distinguish between dissimilar input/output. (E.g., 1518 byte IP, 802.3 frames in; 576 byte, fragmented IP, X.25 frames out.) By extending the single DUT test model, reasonable benchmarks regarding multiple DUTs or heterogeneous environments may be collected. In this extension, the single DUT is replaced by a system of interconnected network DUTs. This test methodology would support the benchmarking of a variety of device/media/service/protocol combinations. For example, a configuration for a LAN-to-WAN-to-LAN test might be: (1) 802.3-> DUT 1 -> X.25 @ 64kbps -> DUT 2 -> 802.3 Or a mixed LAN configuration might be: (2) 802.3 -> DUT 1 -> FDDI -> DUT 2 -> FDDI -> DUT 3 -> 802.3 In both examples 1 and 2, end-to-end benchmarks of each system could be empirically ascertained. Other behavior may be characterized through the use of intermediate devices. In example 2, the configuration may be used to give an indication of the FDDI to FDDI capability exhibited by DUT 2. Because multiple DUTs are treated as a single system, there are limitations to this methodology. For instance, this methodology may yield an aggregate benchmark for a tested system. That benchmark alone, however, may not necessarily reflect asymmetries in behavior between the DUTs, latencies introduce by other apparatus (e.g., CSUs/DSUs, switches), etc. Further, care must be used when comparing benchmarks of different systems by ensuring that the DUTs' features/configuration of the tested systems have the appropriate common denominators to allow comparison. 20. Maximum frame rate The maximum frame rates that should be used when testing LAN connections SHOULD be the listed theoretical maximum rate for the frame size on the media. Bradner & McQuaid Informational [Page 13] RFC 2544 Benchmarking Methodology March 1999 The maximum frame rate that should be used when testing WAN connections SHOULD be greater than the listed theoretical maximum rate for the frame size on that speed connection. The higher rate for WAN tests is to compensate for the fact that some vendors employ various forms of header compression. A list of maximum frame rates for LAN connections is included in Appendix B. 21. Bursty traffic It is convenient to measure the DUT performance under steady state load but this is an unrealistic way to gauge the functioning of a DUT since actual network traffic normally consists of bursts of frames. Some of the tests described below SHOULD be performed with both steady state traffic and with traffic consisting of repeated bursts of frames. The frames within a burst are transmitted with the minimum legitimate inter-frame gap. The objective of the test is to determine the minimum interval between bursts which the DUT can process with no frame loss. During each test the number of frames in each burst is held constant and the inter-burst interval varied. Tests SHOULD be run with burst sizes of 16, 64, 256 and 1024 frames. 22. Frames per token Although it is possible to configure some token ring and FDDI interfaces to transmit more than one frame each time that the token is received, most of the network devices currently available transmit only one frame per token. These tests SHOULD first be performed while transmitting only one frame per token. Some current high-performance workstation servers do transmit more than one frame per token on FDDI to maximize throughput. Since this may be a common feature in future workstations and servers, interconnect devices with FDDI interfaces SHOULD be tested with 1, 4, 8, and 16 frames per token. The reported frame rate SHOULD be the average rate of frame transmission over the total trial period. 23. Trial description A particular test consists of multiple trials. Each trial returns one piece of information, for example the loss rate at a particular input frame rate. Each trial consists of a number of phases: a) If the DUT is a router, send the routing update to the "input" port and pause two seconds to be sure that the routing has settled. Bradner & McQuaid Informational [Page 14] RFC 2544 Benchmarking Methodology March 1999 b) Send the "learning frames" to the "output" port and wait 2 seconds to be sure that the learning has settled. Bridge learning frames are frames with source addresses that are the same as the destination addresses used by the test frames. Learning frames for other protocols are used to prime the address resolution tables in the DUT. The formats of the learning frame that should be used are shown in the Test Frame Formats document. c) Run the test trial. d) Wait for two seconds for any residual frames to be received. e) Wait for at least five seconds for the DUT to restabilize. 24. Trial duration The aim of these tests is to determine the rate continuously supportable by the DUT. The actual duration of the test trials must be a compromise between this aim and the duration of the benchmarking test suite. The duration of the test portion of each trial SHOULD be at least 60 seconds. The tests that involve some form of "binary search", for example the throughput test, to determine the exact result MAY use a shorter trial duration to minimize the length of the search procedure, but the final determination SHOULD be made with full length trials. 25. Address resolution The DUT SHOULD be able to respond to address resolution requests sent by the DUT wherever the protocol requires such a process. 26. Benchmarking tests: Note: The notation "type of data stream" refers to the above modifications to a frame stream with a constant inter-frame gap, for example, the addition of traffic filters to the configuration of the DUT. 26.1 Throughput Objective: To determine the DUT throughput as defined in RFC 1242. Procedure: Send a specific number of frames at a specific rate through the DUT and then count the frames that are transmitted by the DUT. If the count of offered frames is equal to the count of received frames, the fewer frames are received than were transmitted, the rate of the offered stream is reduced and the test is rerun. Bradner & McQuaid Informational [Page 15] RFC 2544 Benchmarking Methodology March 1999 The throughput is the fastest rate at which the count of test frames transmitted by the DUT is equal to the number of test frames sent to it by the test equipment. Reporting format: The results of the throughput test SHOULD be reported in the form of a graph. If it is, the x coordinate SHOULD be the frame size, the y coordinate SHOULD be the frame rate. There SHOULD be at least two lines on the graph. There SHOULD be one line showing the theoretical frame rate for the media at the various frame sizes. The second line SHOULD be the plot of the test results. Additional lines MAY be used on the graph to report the results for each type of data stream tested. Text accompanying the graph SHOULD indicate the protocol, data stream format, and type of media used in the tests. We assume that if a single value is desired for advertising purposes the vendor will select the rate for the minimum frame size for the media. If this is done then the figure MUST be expressed in frames per second. The rate MAY also be expressed in bits (or bytes) per second if the vendor so desires. The statement of performance MUST include a/ the measured maximum frame rate, b/ the size of the frame used, c/ the theoretical limit of the media for that frame size, and d/ the type of protocol used in the test. Even if a single value is used as part of the advertising copy, the full table of results SHOULD be included in the product data sheet. 26.2 Latency Objective: To determine the latency as defined in RFC 1242. Procedure: First determine the throughput for DUT at each of the listed frame sizes. Send a stream of frames at a particular frame size through the DUT at the determined throughput rate to a specific destination. The stream SHOULD be at least 120 seconds in duration. An identifying tag SHOULD be included in one frame after 60 seconds with the type of tag being implementation dependent. The time at which this frame is fully transmitted is recorded (timestamp A). The receiver logic in the test equipment MUST recognize the tag information in the frame stream and record the time at which the tagged frame was received (timestamp B). The latency is timestamp B minus timestamp A as per the relevant definition frm RFC 1242, namely latency as defined for store and forward devices or latency as defined for bit forwarding devices. The test MUST be repeated at least 20 times with the reported value being the average of the recorded values. Bradner & McQuaid Informational [Page 16] RFC 2544 Benchmarking Methodology March 1999 This test SHOULD be performed with the test frame addressed to the same destination as the rest of the data stream and also with each of the test frames addressed to a new destination network. Reporting format: The report MUST state which definition of latency (from RFC 1242) was used for this test. The latency results SHOULD be reported in the format of a table with a row for each of the tested frame sizes. There SHOULD be columns for the frame size, the rate at which the latency test was run for that frame size, for the media types tested, and for the resultant latency values for each type of data stream tested. 26.3 Frame loss rate Objective: To determine the frame loss rate, as defined in RFC 1242, of a DUT throughout the entire range of input data rates and frame sizes. Procedure: Send a specific number of frames at a specific rate through the DUT to be tested and count the frames that are transmitted by the DUT. The frame loss rate at each point is calculated using the following equation: ( ( input_count - output_count ) * 100 ) / input_count The first trial SHOULD be run for the frame rate that corresponds to 100% of the maximum rate for the frame size on the input media. Repeat the procedure for the rate that corresponds to 90% of the maximum rate used and then for 80% of this rate. This sequence SHOULD be continued (at reducing 10% intervals) until there are two successive trials in which no frames are lost. The maximum granularity of the trials MUST be 10% of the maximum rate, a finer granularity is encouraged. Reporting format: The results of the frame loss rate test SHOULD be plotted as a graph. If this is done then the X axis MUST be the input frame rate as a percent of the theoretical rate for the media at the specific frame size. The Y axis MUST be the percent loss at the particular input rate. The left end of the X axis and the bottom of the Y axis MUST be 0 percent; the right end of the X axis and the top of the Y axis MUST be 100 percent. Multiple lines on the graph MAY used to report the frame loss rate for different frame sizes, protocols, and types of data streams. Note: See section 18 for the maximum frame rates that SHOULD be used. Bradner & McQuaid Informational [Page 17] RFC 2544 Benchmarking Methodology March 1999 26.4 Back-to-back frames Objective: To characterize the ability of a DUT to process back-to- back frames as defined in RFC 1242. Procedure: Send a burst of frames with minimum inter-frame gaps to the DUT and count the number of frames forwarded by the DUT. If the count of transmitted frames is equal to the number of frames forwarded the length of the burst is increased and the test is rerun. If the number of forwarded frames is less than the number transmitted, the length of the burst is reduced and the test is rerun. The back-to-back value is the number of frames in the longest burst that the DUT will handle without the loss of any frames. The trial length MUST be at least 2 seconds and SHOULD be repeated at least 50 times with the average of the recorded values being reported. Reporting format: The back-to-back results SHOULD be reported in the format of a table with a row for each of the tested frame sizes. There SHOULD be columns for the frame size and for the resultant average frame count for each type of data stream tested. The standard deviation for each measurement MAY also be reported. 26.5 System recovery Objective: To characterize the speed at which a DUT recovers from an overload condition. Procedure: First determine the throughput for a DUT at each of the listed frame sizes. Send a stream of frames at a rate 110% of the recorded throughput rate or the maximum rate for the media, whichever is lower, for at least 60 seconds. At Timestamp A reduce the frame rate to 50% of the above rate and record the time of the last frame lost (Timestamp B). The system recovery time is determined by subtracting Timestamp B from Timestamp A. The test SHOULD be repeated a number of times and the average of the recorded values being reported. Reporting format: The system recovery results SHOULD be reported in the format of a table with a row for each of the tested frame sizes. There SHOULD be columns for the frame size, the frame rate used as the throughput rate for each type of data stream tested, and for the measured recovery time for each type of data stream tested. Bradner & McQuaid Informational [Page 18] RFC 2544 Benchmarking Methodology March 1999 26.6 Reset Objective: To characterize the speed at which a DUT recovers from a device or software reset. Procedure: First determine the throughput for the DUT for the minimum frame size on the media used in the testing. Send a continuous stream of frames at the determined throughput rate for the minimum sized frames. Cause a reset in the DUT. Monitor the output until frames begin to be forwarded and record the time that the last frame (Timestamp A) of the initial stream and the first frame of the new stream (Timestamp B) are received. A power interruption reset test is performed as above except that the power to the DUT should be interrupted for 10 seconds in place of causing a reset. This test SHOULD only be run using frames addressed to networks directly connected to the DUT so that there is no requirement to delay until a routing update is received. The reset value is obtained by subtracting Timestamp A from Timestamp B. Hardware and software resets, as well as a power interruption SHOULD be tested. Reporting format: The reset value SHOULD be reported in a simple set of statements, one for each reset type. 27. Security Considerations Security issues are not addressed in this document. Bradner & McQuaid Informational [Page 19] RFC 2544 Benchmarking Methodology March 1999 28. Editors' Addresses Scott Bradner Harvard University 1350 Mass. Ave, room 813 Cambridge, MA 02138 Phone: +1 617 495-3864 Fax: +1 617 496-8500 EMail: sob@harvard.edu Jim McQuaid NetScout Systems 4 Westford Tech Park Drive Westford, MA 01886 Phone: +1 978 614-4116 Fax: +1 978 614-4004 EMail: mcquaidj@netscout.com Bradner & McQuaid Informational [Page 20] RFC 2544 Benchmarking Methodology March 1999 Appendix A: Testing Considerations A.1 Scope Of This Appendix This appendix discusses certain issues in the benchmarking methodology where experience or judgment may play a role in the tests selected to be run or in the approach to constructing the test with a particular DUT. As such, this appendix MUST not be read as an amendment to the methodology described in the body of this document but as a guide to testing practice. 1. Typical testing practice has been to enable all protocols to be tested and conduct all testing with no further configuration of protocols, even though a given set of trials may exercise only one protocol at a time. This minimizes the opportunities to "tune" a DUT for a single protocol. 2. The least common denominator of the available filter functions should be used to ensure that there is a basis for comparison between vendors. Because of product differences, those conducting and evaluating tests must make a judgment about this issue. 3. Architectural considerations may need to be considered. For example, first perform the tests with the stream going between ports on the same interface card and the repeat the tests with the stream going into a port on one interface card and out of a port on a second interface card. There will almost always be a best case and worst case configuration for a given DUT architecture. 4. Testing done using traffic streams consisting of mixed protocols has not shown much difference between testing with individual protocols. That is, if protocol A testing and protocol B testing give two different performance results, mixed protocol testing appears to give a result which is the average of the two. 5. Wide Area Network (WAN) performance may be tested by setting up two identical devices connected by the appropriate short- haul versions of the WAN modems. Performance is then measured between a LAN interface on one DUT to a LAN interface on the other DUT. The maximum frame rate to be used for LAN-WAN-LAN configurations is a judgment that can be based on known characteristics of the overall system including compression effects, fragmentation, and gross link speeds. Practice suggests that the rate should be at least 110% of the slowest link speed. Substantive issues of testing compression itself are beyond the scope of this document. Bradner & McQuaid Informational [Page 21] RFC 2544 Benchmarking Methodology March 1999 Appendix B: Maximum frame rates reference (Provided by Roger Beeman, Cisco Systems) Size Ethernet 16Mb Token Ring FDDI (bytes) (pps) (pps) (pps) 64 14880 24691 152439 128 8445 13793 85616 256 4528 7326 45620 512 2349 3780 23585 768 1586 2547 15903 1024 1197 1921 11996 1280 961 1542 9630 1518 812 1302 8138 Ethernet size Preamble 64 bits Frame 8 x N bits Gap 96 bits 16Mb Token Ring size SD 8 bits AC 8 bits FC 8 bits DA 48 bits SA 48 bits RI 48 bits ( 06 30 00 12 00 30 ) SNAP DSAP 8 bits SSAP 8 bits Control 8 bits Vendor 24 bits Type 16 bits Data 8 x ( N - 18) bits FCS 32 bits ED 8 bits FS 8 bits Tokens or idles between packets are not included FDDI size Preamble 64 bits SD 8 bits FC 8 bits DA 48 bits SA 48 bits SNAP Bradner & McQuaid Informational [Page 22] RFC 2544 Benchmarking Methodology March 1999 DSAP 8 bits SSAP 8 bits Control 8 bits Vendor 24 bits Type 16 bits Data 8 x ( N - 18) bits FCS 32 bits ED 4 bits FS 12 bits Bradner & McQuaid Informational [Page 23] RFC 2544 Benchmarking Methodology March 1999 Appendix C: Test Frame Formats This appendix defines the frame formats that may be used with these tests. It also includes protocol specific parameters for TCP/IP over Ethernet to be used with the tests as an example. C.1. Introduction The general logic used in the selection of the parameters and the design of the frame formats is explained for each case within the TCP/IP section. The same logic has been used in the other sections. Comments are used in these sections only if there is a protocol specific feature to be explained. Parameters and frame formats for additional protocols can be defined by the reader by using the same logic. C.2. TCP/IP Information The following section deals with the TCP/IP protocol suite. C.2.1 Frame Type. An application level datagram echo request is used for the test data frame in the protocols that support such a function. A datagram protocol is used to minimize the chance that a router might expect a specific session initialization sequence, as might be the case for a reliable stream protocol. A specific defined protocol is used because some routers verify the protocol field and refuse to forward unknown protocols. For TCP/IP a UDP Echo Request is used. C.2.2 Protocol Addresses Two sets of addresses must be defined: first the addresses assigned to the router ports, and second the address that are to be used in the frames themselves and in the routing updates. The network addresses 192.18.0.0 through 198.19.255.255 are have been assigned to the BMWG by the IANA for this purpose. This assignment was made to minimize the chance of conflict in case a testing device were to be accidentally connected to part of the Internet. The specific use of the addresses is detailed below. Bradner & McQuaid Informational [Page 24] RFC 2544 Benchmarking Methodology March 1999 C.2.2.1 Router port protocol addresses Half of the ports on a multi-port router are referred to as "input" ports and the other half as "output" ports even though some of the tests use all ports both as input and output. A contiguous series of IP Class C network addresses from 198.18.1.0 to 198.18.64.0 have been assigned for use on the "input" ports. A second series from 198.19.1.0 to 198.19.64.0 have been assigned for use on the "output" ports. In all cases the router port is node 1 on the appropriate network. For example, a two port DUT would have an IP address of 198.18.1.1 on one port and 198.19.1.1 on the other port. Some of the tests described in the methodology memo make use of an SNMP management connection to the DUT. The management access address for the DUT is assumed to be the first of the "input" ports (198.18.1.1). C.2.2.2 Frame addresses Some of the described tests assume adjacent network routing (the reboot time test for example). The IP address used in the test frame is that of node 2 on the appropriate Class C network. (198.19.1.2 for example) If the test involves non-adjacent network routing the phantom routers are located at node 10 of each of the appropriate Class C networks. A series of Class C network addresses from 198.18.65.0 to 198.18.254.0 has been assigned for use as the networks accessible through the phantom routers on the "input" side of DUT. The series of Class C networks from 198.19.65.0 to 198.19.254.0 have been assigned to be used as the networks visible through the phantom routers on the "output" side of the DUT. C.2.3 Routing Update Frequency The update interval for each routing protocol is may have to be determined by the specifications of the individual protocol. For IP RIP, Cisco IGRP and for OSPF a routing update frame or frames should precede each stream of test frames by 5 seconds. This frequency is sufficient for trial durations of up to 60 seconds. Routing updates must be mixed with the stream of test frames if longer trial periods are selected. The frequency of updates should be taken from the following table. IP-RIP 30 sec IGRP 90 sec OSPF 90 sec Bradner & McQuaid Informational [Page 25] RFC 2544 Benchmarking Methodology March 1999 C.2.4 Frame Formats - detailed discussion C.2.4.1 Learning Frame In most protocols a procedure is used to determine the mapping between the protocol node address and the MAC address. The Address Resolution Protocol (ARP) is used to perform this function in TCP/IP. No such procedure is required in XNS or IPX because the MAC address is used as the protocol node address. In the ideal case the tester would be able to respond to ARP requests from the DUT. In cases where this is not possible an ARP request should be sent to the router's "output" port. This request should be seen as coming from the immediate destination of the test frame stream. (i.e. the phantom router (Figure 2) or the end node if adjacent network routing is being used.) It is assumed that the router will cache the MAC address of the requesting device. The ARP request should be sent 5 seconds before the test frame stream starts in each trial. Trial lengths of longer than 50 seconds may require that the router be configured for an extended ARP timeout. +--------+ +------------+ | | | phantom |------ P LAN A IN A------| DUT |------------| |------ P LAN B | | OUT A | router |------ P LAN C +--------+ +------------+ Figure 2 In the case where full routing is being used C.2.4.2 Routing Update Frame If the test does not involve adjacent net routing the tester must supply proper routing information using a routing update. A single routing update is used before each trial on each "destination" port (see section C.24). This update includes the network addresses that are reachable through a phantom router on the network attached to the port. For a full mesh test, one destination network address is present in the routing update for each of the "input" ports. The test stream on each "input" port consists of a repeating sequence of frames, one to each of the "output" ports. Bradner & McQuaid Informational [Page 26] RFC 2544 Benchmarking Methodology March 1999 C.2.4.3 Management Query Frame The management overhead test uses SNMP to query a set of variables that should be present in all DUTs that support SNMP. The variables for a single interface only are read by an NMS at the appropriate intervals. The list of variables to retrieve follow: sysUpTime ifInOctets ifOutOctets ifInUcastPkts ifOutUcastPkts C.2.4.4 Test Frames The test frame is an UDP Echo Request with enough data to fill out the required frame size. The data should not be all bits off or all bits on since these patters can cause a "bit stuffing" process to be used to maintain clock synchronization on WAN links. This process will result in a longer frame than was intended. C.2.4.5 Frame Formats - TCP/IP on Ethernet Each of the frames below are described for the 1st pair of DUT ports, i.e. "input" port #1 and "output" port #1. Addresses must be changed if the frame is to be used for other ports. C.2.6.1 Learning Frame ARP Request on Ethernet -- DATAGRAM HEADER offset data (hex) description 00 FF FF FF FF FF FF dest MAC address send to broadcast address 06 xx xx xx xx xx xx set to source MAC address 12 08 06 ARP type 14 00 01 hardware type Ethernet = 1 16 08 00 protocol type IP = 800 18 06 hardware address length 48 bits on Ethernet 19 04 protocol address length 4 octets for IP 20 00 01 opcode request = 1 22 xx xx xx xx xx xx source MAC address 28 xx xx xx xx source IP address 32 FF FF FF FF FF FF requesting DUT's MAC address 38 xx xx xx xx DUT's IP address Bradner & McQuaid Informational [Page 27] RFC 2544 Benchmarking Methodology March 1999 C.2.6.2 Routing Update Frame -- DATAGRAM HEADER offset data (hex) description 00 FF FF FF FF FF FF dest MAC address is broadcast 06 xx xx xx xx xx xx source hardware address 12 08 00 type -- IP HEADER 14 45 IP version - 4, header length (4 byte units) - 5 15 00 service field 16 00 EE total length 18 00 00 ID 20 40 00 flags (3 bits) 4 (do not fragment), fragment offset-0 22 0A TTL 23 11 protocol - 17 (UDP) 24 C4 8D header checksum 26 xx xx xx xx source IP address 30 xx xx xx destination IP address 33 FF host part = FF for broadcast -- UDP HEADER 34 02 08 source port 208 = RIP 36 02 08 destination port 208 = RIP 38 00 DA UDP message length 40 00 00 UDP checksum -- RIP packet 42 02 command = response 43 01 version = 1 44 00 00 0 -- net 1 46 00 02 family = IP 48 00 00 0 50 xx xx xx net 1 IP address 53 00 net not node 54 00 00 00 00 0 58 00 00 00 00 0 62 00 00 00 07 metric 7 -- net 2 66 00 02 family = IP 68 00 00 0 70 xx xx xx net 2 IP address Bradner & McQuaid Informational [Page 28] RFC 2544 Benchmarking Methodology March 1999 73 00 net not node 74 00 00 00 00 0 78 00 00 00 00 0 82 00 00 00 07 metric 7 -- net 3 86 00 02 family = IP 88 00 00 0 90 xx xx xx net 3 IP address 93 00 net not node 94 00 00 00 00 0 98 00 00 00 00 0 102 00 00 00 07 metric 7 -- net 4 106 00 02 family = IP 108 00 00 0 110 xx xx xx net 4 IP address 113 00 net not node 114 00 00 00 00 0 118 00 00 00 00 0 122 00 00 00 07 metric 7 -- net 5 126 00 02 family = IP 128 00 00 0 130 00 net 5 IP address 133 00 net not node 134 00 00 00 00 0 138 00 00 00 00 0 142 00 00 00 07 metric 7 -- net 6 146 00 02 family = IP 148 00 00 0 150 xx xx xx net 6 IP address 153 00 net not node 154 00 00 00 00 0 158 00 00 00 00 0 162 00 00 00 07 metric 7 C.2.4.6 Management Query Frame To be defined. C.2.6.4 Test Frames UDP echo request on Ethernet Bradner & McQuaid Informational [Page 29] RFC 2544 Benchmarking Methodology March 1999 -- DATAGRAM HEADER offset data (hex) description 00 xx xx xx xx xx xx set to dest MAC address 06 xx xx xx xx xx xx set to source MAC address 12 08 00 type -- IP HEADER 14 45 IP version - 4 header length 5 4 byte units 15 00 TOS 16 00 2E total length* 18 00 00 ID 20 00 00 flags (3 bits) - 0 fragment offset-0 22 0A TTL 23 11 protocol - 17 (UDP) 24 C4 8D header checksum* 26 xx xx xx xx set to source IP address** 30 xx xx xx xx set to destination IP address** -- UDP HEADER 34 C0 20 source port 36 00 07 destination port 07 = Echo 38 00 1A UDP message length* 40 00 00 UDP checksum -- UDP DATA 42 00 01 02 03 04 05 06 07 some data*** 50 08 09 0A 0B 0C 0D 0E 0F * - change for different length frames ** - change for different logical streams *** - fill remainder of frame with incrementing octets, repeated if required by frame length Values to be used in Total Length and UDP message length fields: frame size total length UDP message length 64 00 2E 00 1A 128 00 6E 00 5A 256 00 EE 00 9A 512 01 EE 01 9A 768 02 EE 02 9A 1024 03 EE 03 9A 1280 04 EE 04 9A 1518 05 DC 05 C8 Bradner & McQuaid Informational [Page 30]Elkins, et al. Expires 28 August 2024 [Page 7] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 5.3. Security Goals for Authentication An unauthorized party MUST NOT be able to send PDM data and MUST NOT be able to authorize another entity to do so. Alternatively, if authentication is done via any of the following, this requirement MAY be considered to be met. a) PDM is used over an already authenticated medium (For example, TLS session). b) PDM is used in a link-local scenario. c) PDM is used in a corporate network where security measures are strong enough to consider the presence of a malicious actor a negligible risk. 5.4. Cryptographic Algorithm Symmetric key cryptography has performance benefits over asymmetric cryptography; asymmetric cryptography is better for key management. Encryption schemes that unite both have been specified in [RFC1421], and have been participating practically since the early days of public-key cryptography. The basic mechanism is to encrypt the symmetric key with the public key by joining both yields. Hybrid public-key encryption schemes (HPKE) [RFC9180] used a different approach that generates the symmetric key and its encapsulation with the public key of the receiver. It is RECOMMENDED to use the HPKE framework that incorporates key encapsulation mechanism (KEM), key derivation function (KDF) and authenticated encryption with associated data (AEAD). These multiple schemes are more robust and significantly more efficient than other schemes. While the schemes may be negotiated between communicating parties, it is RECOMMENDED to use default encryption algorithm for HPKE AEAD as AES-128-GCM. 6. PDMv2 Destination Options 6.1. Destinations Option Header The IPv6 Destination Options extension header [RFC8200] is used to carry optional information that needs to be examined only by a packet's destination node(s). The Destination Options header is identified by a Next Header value of 60 in the immediately preceding header and is defined in RFC 8200 [RFC8200]. The IPv6 PDMv2 destination option is implemented as an IPv6 Option carried in the Destination Options header. Elkins, et al. Expires 28 August 2024 [Page 8] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 6.2. Metrics information in PDMv2 The IPv6 PDMv2 destination option contains the following base fields: SCALEDTLR: Scale for Delta Time Last Received SCALEDTLS: Scale for Delta Time Last Sent GLOBALPTR: Global Pointer PSNTP: Packet Sequence Number This Packet PSNLR: Packet Sequence Number Last Received DELTATLR: Delta Time Last Received DELTATLS: Delta Time Last Sent PDMv2 adds a new metric to the existing PDM [RFC8250] called the Global Pointer. The existing PDM fields are identified with respect to the identifying information called a "5-tuple". The 5-tuple consists of: SADDR: IP address of the sender SPORT: Port for the sender DADDR: IP address of the destination DPORT: Port for the destination PROTC: Upper-layer protocol (TCP, UDP, ICMP, etc.) Unlike PDM fields, Global Pointer (GLOBALPTR) field in PDMv2 is defined for the SADDR type. Following are the SADDR address types considered: a) Link-Local b) Global Unicast The Global Pointer is treated as a common entity over all the 5-tuples with the same SADDR type. It is initialised to the value 1 and increments for every packet sent. Global Pointer provides a measure of the amount of IPv6 traffic sent by the PDMv2 node. Elkins, et al. Expires 28 August 2024 [Page 9] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 When the SADDR type is Link-Local, the PDMv2 node sends Global Pointer defined for Link-Local addresses, and when the SADDR type is Global Unicast, it sends the one defined for Global Unicast addresses. 6.3. PDMv2 Layout PDMv2 has two different header formats corresponding to whether the metric contents are encrypted or unencrypted. The difference between the two types of headers is determined from the Options Length value. Following is the representation of the unencrypted PDMv2 header: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Option Length | Vrsn | Epoch | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PSN This Packet | Reserved Bits | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Global Pointer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ScaleDTLR | ScaleDTLS | PSN Last Received | |-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Delta Time Last Received | Delta Time Last Sent | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Following is the representation of the encrypted PDMv2 header: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Option Length | Vrsn | Epoch | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PSN This Packet | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ : | Encrypted PDM Data : : (30 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Option Type 0x0F 8-bit unsigned integer. The Option Type is adopted from RFC 8250 [RFC8250]. Option Length Elkins, et al. Expires 28 August 2024 [Page 10] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 0x12: Unencrypted PDM 0x22: Encrypted PDM 8-bit unsigned integer. Length of the option, in octets, excluding the Option Type and Option Length fields. The options length is used for differentiating PDM [RFC8250], unencrypted PDMv2 and encrypted PDMv2. Version Number 0x2 4-bit unsigned number. Epoch 12-bit unsigned number. Epoch field is used to indicate the valid SessionTemporaryKey. Packet Sequence Number This Packet (PSNTP) 16-bit unsigned number. This field is initialized at a random number and is incremented sequentially for each packet of the 5-tuple. This field is also used in the Encrypted PDMv2 as the encryption nonce. The nonce MUST NOT be reused in different sessions. Reserved Bits 16-bits. Reserved bits for future use. They MUST be set to zero on transmission and ignored on receipt per [RFC3552]. Scale Delta Time Last Received (SCALEDTLR) 8-bit unsigned number. This is the scaling value for the Delta Time Last Sent (DELTATLS) field. Scale Delta Time Last Sent (SCALEDTLS) 8-bit unsigned number. Elkins, et al. Expires 28 August 2024 [Page 11] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 This is the scaling value for the Delta Time Last Sent (DELTATLS) field. Global Pointer 32-bit unsigned number. Global Pointer is initialized to 1 for the different source address types and incremented sequentially for each packet with the corresponding source address type. This field stores the Global Pointer type corresponding to the SADDR type of the packet. Packet Sequence Number Last Received (PSNLR) 16-bit unsigned number. This field is the PSNTP of the last received packet on the 5-tuple. Delta Time Last Received (DELTATLR) 16-bit unsigned integer. The value is set according to the scale in SCALEDTLR. Delta Time Last Received = (send time packet n - receive time packet (n - 1)) Delta Time Last Sent (DELTATLS) 16-bit unsigned integer. The value is set according to the scale in SCALEDTLS. Delta Time Last Sent = (receive time packet n - send time packet (n - 1)) 7. Security Considerations PDMv2 carries metadata, including information about network characteristics and end-to-end response time. This metadata is used to optimize communication. However, in the context of passive attacks, the information contained within PDMv2 packets can be intercepted by an attacker, and in the context of active attacks the metadata can be modified by an attacker. Elkins, et al. Expires 28 August 2024 [Page 12] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 In the following we will briefly outline the threat model and the associated security risks, using RFC3552 terminology and classification. 7.1. Limited Threat Model We assume that the attacker does not control the endpoints, but it does have a limited control of the network, i.e., it can either monitor the communications (leading to passive attacks), or modify/ forge packets (active attacks). 7.1.1. Passive attacks with unencrypted PDMv2 Passive Attack Scenario: In a passive attack, the attacker seeks to obtain information that the sender and receiver of the communication would prefer to keep private. In this case, the attacker is not altering the packets but is intercepting and analyzing them. Here's how this can happen in the context of unencrypted PDMv2: a. Being on the same LAN: The simplest way for an attacker to launch a passive attack is to be on the same Local Area Network (LAN) as the victim. Many LAN configurations, such as Ethernet, 802.3, and FDDI, allow any machine on the network to read all traffic destined for any other machine on the same LAN. This means that if PDM packets are sent over the LAN, the attacker can capture them. b. Control of a Host in the Communication Path: If the attacker has control over a host that lies in the communication path between two victim machines, they can intercept PDM packets as they pass through this compromised host. This allows the attacker to collect metadata without being on the same LAN as the victim. c. Compromising Routing Infrastructure: In some cases, attackers may actively compromise the routing infrastructure to route traffic through a compromised machine. This can facilitate a passive attack on victim machines. By manipulating routing, the attacker can ensure that PDMv2 packets pass through their controlled node. d. Wireless Networks: Wireless communication channels, such as those using 802.11 (Wi-Fi), are particularly vulnerable to passive attacks. Since data is broadcast over well-known radio frequencies, an attacker with the ability to receive those transmissions can intercept PDMv2 packets. Weak or ineffective cryptographic protection in wireless networks can make it easier for attackers to capture this data. Elkins, et al. Expires 28 August 2024 [Page 13] Internet-Draft draft-ietf-ippm-encrypted-pdmv2 February 2024 RFC 2544 Benchmarking Methodology March 1999 Full Copyright Statement Copyright (C) The Internet Society (1999). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS 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. Bradner & McQuaid Informational [Page 31]