--- 1/draft-ietf-mpls-lsp-ping-10.txt 2006-02-04 17:16:03.000000000 +0100 +++ 2/draft-ietf-mpls-lsp-ping-11.txt 2006-02-04 17:16:03.000000000 +0100 @@ -1,23 +1,23 @@ Network Working Group Kireeti Kompella Internet Draft Juniper Networks, Inc. Category: Standards Track -Expiration Date: March 2006 +Expiration Date: May 2006 George Swallow Cisco Systems, Inc. - September 2005 + November 2005 Detecting MPLS Data Plane Failures - draft-ietf-mpls-lsp-ping-10.txt + draft-ietf-mpls-lsp-ping-11.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 @@ -37,78 +37,62 @@ Abstract This document describes a simple and efficient mechanism that can be used to detect data plane failures in Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs). There are two parts to this document: information carried in an MPLS "echo request" and "echo reply" for the purposes of fault detection and isolation; and mechanisms for reliably sending the echo reply. -Changes since last revision - - (This section to be removed before publication.) - - o Corrected Length of Nil Fec in the summary table at the beginning - of Sec 3.2 - - o Aligned the FEC 129 sub-tlv with draft-ietf-pwe3-control- - protocol-17 - - o Removed the duplicated Interface field from the Interface and - Label Stack object and removed the adjective "Downstream" from the - field descriptions in the text. (Sec. 3.6) - - o Updated the Security section - Contents - 1 Introduction .............................................. 4 - 1.1 Conventions ............................................... 4 - 1.2 Structure of this document ................................ 4 - 1.3 Contributors .............................................. 4 - 2 Motivation ................................................ 5 - 3 Packet Format ............................................. 6 - 3.1 Return Codes .............................................. 10 - 3.2 Target FEC Stack .......................................... 11 - 3.2.1 LDP IPv4 Prefix ........................................... 12 - 3.2.2 LDP IPv6 Prefix ........................................... 12 - 3.2.3 RSVP IPv4 LSP ............................................. 13 - 3.2.4 RSVP IPv6 LSP ............................................. 13 - 3.2.5 VPN IPv4 Prefix ........................................... 14 + 1 Introduction .............................................. 3 + 1.1 Conventions ............................................... 3 + 1.2 Structure of this document ................................ 3 + 1.3 Contributors .............................................. 3 + 2 Motivation ................................................ 4 + 3 Packet Format ............................................. 5 + 3.1 Return Codes .............................................. 9 + 3.2 Target FEC Stack .......................................... 10 + 3.2.1 LDP IPv4 Prefix ........................................... 11 + 3.2.2 LDP IPv6 Prefix ........................................... 11 + 3.2.3 RSVP IPv4 LSP ............................................. 12 + 3.2.4 RSVP IPv6 LSP ............................................. 12 + 3.2.5 VPN IPv4 Prefix ........................................... 13 3.2.6 VPN IPv6 Prefix ........................................... 14 - 3.2.7 L2 VPN Endpoint ........................................... 15 + 3.2.7 L2 VPN Endpoint ........................................... 14 3.2.8 FEC 128 Pseudowire (Deprecated) ........................... 15 - 3.2.9 FEC 128 Pseudowire (Current) .............................. 16 + 3.2.9 FEC 128 Pseudowire (Current) .............................. 15 3.2.10 FEC 129 Pseudowire ........................................ 16 - 3.2.11 BGP Labeled IPv4 Prefix ................................... 17 + 3.2.11 BGP Labeled IPv4 Prefix ................................... 16 3.2.12 BGP Labeled IPv6 Prefix ................................... 17 - 3.2.13 Generic IPv4 Prefix ....................................... 18 + 3.2.13 Generic IPv4 Prefix ....................................... 17 3.2.14 Generic IPv6 Prefix ....................................... 18 - 3.2.15 Nil FEC ................................................... 19 + 3.2.15 Nil FEC ................................................... 18 3.3 Downstream Mapping ........................................ 19 - 3.3.1 Multipath Information Encoding ............................ 24 - 3.3.2 Downstream Router and Interface ........................... 26 - 3.4 Pad TLV ................................................... 26 - 3.5 Vendor Enterprise Code .................................... 27 - 3.6 Interface and Label Stack ................................. 27 + 3.3.1 Multipath Information Encoding ............................ 23 + 3.3.2 Downstream Router and Interface ........................... 25 + 3.4 Pad TLV ................................................... 25 + 3.5 Vendor Enterprise Code .................................... 26 + 3.6 Interface and Label Stack ................................. 26 3.7 Errored TLVs .............................................. 28 - 3.8 Reply TOS Byte TLV ........................................ 29 + 3.8 Reply TOS Byte TLV ........................................ 28 4 Theory of Operation ....................................... 29 - 4.1 Dealing with Equal-Cost Multi-Path (ECMP) ................. 30 - 4.2 Testing LSPs That Are Used to Carry MPLS Payloads ......... 31 - 4.3 Sending an MPLS Echo Request .............................. 31 - 4.4 Receiving an MPLS Echo Request ............................ 32 - 4.5 Sending an MPLS Echo Reply ................................ 35 - 4.6 Receiving an MPLS Echo Reply .............................. 36 + 4.1 Dealing with Equal-Cost Multi-Path (ECMP) ................. 29 + 4.2 Testing LSPs That Are Used to Carry MPLS Payloads ......... 30 + 4.3 Sending an MPLS Echo Request .............................. 30 + 4.4 Receiving an MPLS Echo Request ............................ 31 + 4.5 Sending an MPLS Echo Reply ................................ 34 + 4.6 Receiving an MPLS Echo Reply .............................. 35 4.7 Issue with VPN IPv4 and IPv6 Prefixes ..................... 36 - 4.8 Non-compliant Routers ..................................... 37 + 4.8 Non-compliant Routers ..................................... 36 5 References ................................................ 37 6 Security Considerations ................................... 38 7 IANA Considerations ....................................... 38 7.1 Message Types, Reply Modes, Return Codes .................. 39 7.2 TLVs ...................................................... 40 8 Acknowledgments ........................................... 41 1. Introduction This document describes a simple and efficient mechanism that can be @@ -127,20 +111,24 @@ and secondarily to verify the data plane against the control plane. Mechanisms to check the control plane are valuable, but are not cov- ered in this document. 1.1. Conventions 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 [KEYWORDS]. + The term "Must be Zero" (MBZ) is used in object decriptions for + reserved fields. These fields MUST be set to zero when sent and + ignored on receipt. + 1.2. Structure of this document The body of this memo contains four main parts: motivation, MPLS echo request/reply packet format, LSP ping operation, and a reliable return path. It is suggested that first-time readers skip the actual packet formats and read the Theory of Operation first; the document is structured the way it is to avoid forward references. 1.3. Contributors @@ -163,36 +151,36 @@ isolate faults. In this document, we describe a mechanism that accomplishes these goals. This mechanism is modeled after the ping/traceroute paradigm: ping (ICMP echo request [ICMP]) is used for connectivity checks, and traceroute is used for hop-by-hop fault localization as well as path tracing. This document specifies a "ping mode" and a "traceroute" mode for testing MPLS LSPs. The basic idea is to verify that packets that belong to a particular - Forwarding Equivalence Class (FEC) actually end their MPLS path on an - LSR that is an egress for that FEC. This document proposes that this - test be carried out by sending a packet (called an "MPLS echo - request") along the same data path as other packets belonging to this - FEC. An MPLS echo request also carries information about the FEC - whose MPLS path is being verified. This echo request is forwarded - just like any other packet belonging to that FEC. In "ping" mode - (basic connectivity check), the packet should reach the end of the - path, at which point it is sent to the control plane of the egress - LSR, which then verifies whether it is indeed an egress for the FEC. - In "traceroute" mode (fault isolation), the packet is sent to the - control plane of each transit LSR, which performs various checks that - it is indeed a transit LSR for this path; this LSR also returns fur- - ther information that helps check the control plane against the data - plane, i.e., that forwarding matches what the routing protocols - determined as the path. + Forwarding Equivalence Class (FEC) actually end their MPLS path on a + Label Switching Router (LSR) that is an egress for that FEC. This + document proposes that this test be carried out by sending a packet + (called an "MPLS echo request") along the same data path as other + packets belonging to this FEC. An MPLS echo request also carries + information about the FEC whose MPLS path is being verified. This + echo request is forwarded just like any other packet belonging to + that FEC. In "ping" mode (basic connectivity check), the packet + should reach the end of the path, at which point it is sent to the + control plane of the egress LSR, which then verifies whether it is + indeed an egress for the FEC. In "traceroute" mode (fault isola- + tion), the packet is sent to the control plane of each transit LSR, + which performs various checks that it is indeed a transit LSR for + this path; this LSR also returns further information that helps check + the control plane against the data plane, i.e., that forwarding + matches what the routing protocols determined as the path. One way these tools can be used is to periodically ping a FEC to ensure connectivity. If the ping fails, one can then initiate a traceroute to determine where the fault lies. One can also periodi- cally traceroute FECs to verify that forwarding matches the control plane; however, this places a greater burden on transit LSRs and thus should be used with caution. 3. Packet Format @@ -257,50 +245,53 @@ The Reply Mode can take one of the following values: Value Meaning ----- ------- 1 Do not reply 2 Reply via an IPv4/IPv6 UDP packet 3 Reply via an IPv4/IPv6 UDP packet with Router Alert 4 Reply via application level control channel - An MPLS echo request with "Do not reply" may be used for one-way con- - nectivity tests; the receiving router may log gaps in the sequence - numbers and/or maintain delay/jitter statistics. An MPLS echo - request would normally have "Reply via an IPv4/IPv6 UDP packet"; if - the normal IP return path is deemed unreliable, one may use "Reply - via an IPv4/IPv6 UDP packet with Router Alert" (note that this - requires that all intermediate routers understand and know how to - forward MPLS echo replies). The echo reply uses the same IP version - number as the received echo request, i.e., an IPv4 encapsulated echo - reply is sent in response to an IPv4 encapsulated echo request. + An MPLS echo request with 1 (Do not reply) in the Reply Mode field + may be used for one-way connectivity tests; the receiving router may + log gaps in the sequence numbers and/or maintain delay/jitter statis- + tics. An MPLS echo request would normally have 2 (Reply via an + IPv4/IPv6 UDP packet) in the Reply Mode field. If the normal IP + return path is deemed unreliable, one may use 3 (Reply via an + IPv4/IPv6 UDP packet with Router Alert). Note that this requires + that all intermediate routers understand and know how to forward MPLS + echo replies. The echo reply uses the same IP version number as the + received echo request, i.e., an IPv4 encapsulated echo reply is sent + in response to an IPv4 encapsulated echo request. Any application which supports an IP control channel between its con- - trol entities may set the Reply Mode to 4 to ensure that replies use - that same channel. Further definition of this codepoint is applica- - tion specific and thus beyond the scope of this document. + trol entities may set the Reply Mode to 4 (Reply via application + level control channel) to ensure that replies use that same channel. + Further definition of this codepoint is application specific and thus + beyond the scope of this document. Return Codes and Subcodes are described in the next section. the Sender's Handle is filled in by the sender, and returned unchanged by the receiver in the echo reply (if any). There are no semantics associated with this handle, although a sender may find this useful for matching up requests with replies. The Sequence Number is assigned by the sender of the MPLS echo request, and can be (for example) used to detect missed replies. The TimeStamp Sent is the time-of-day (in seconds and microseconds, - wrt the sender's clock) when the MPLS echo request is sent. The - TimeStamp Received in an echo reply is the time-of-day (wrt the - receiver's clock) that the corresponding echo request was received. + according to the sender's clock) when the MPLS echo request is sent. + The TimeStamp Received in an echo reply is the time-of-day (according + to the receiver's clock) that the corresponding echo request was + received. TLVs (Type-Length-Value tuples) have the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value | . . @@ -322,34 +313,34 @@ 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 1 (LDP IPv4 FEC) | Length = 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The Length for this TLV is 5. A Target FEC Stack TLV which contains - an LDP IPv4 FEC sub-TLV and a VPN IPv4 FEC sub-TLV has the format: + an LDP IPv4 FEC sub-TLV and a VPN IPv4 prefix sub-TLV has the format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 1 (FEC TLV) | Length = 12 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-Type = 1 (LDP IPv4 FEC) | Length = 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | sub-Type = 6 (VPN IPv4 FEC) | Length = 13 | + | sub-Type = 6 (VPN IPv4 prefix)| Length = 13 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Distinguisher | | (8 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ A description of the Types and Values of the top level TLVs for LSP @@ -452,101 +443,106 @@ 15 17 Generic IPv6 prefix 16 4 Nil FEC Other FEC Types will be defined as needed. Note that this TLV defines a stack of FECs, the first FEC element corresponding to the top of the label stack, etc. An MPLS echo request MUST have a Target FEC Stack that describes the FEC stack being tested. For example, if an LSR X has an LDP mapping - for 192.168.1.1 (say label 1001), then to verify that label 1001 does - indeed reach an egress LSR that announced this prefix via LDP, X can - send an MPLS echo request with a FEC Stack TLV with one FEC in it, - namely of type LDP IPv4 prefix, with prefix 192.168.1.1/32, and send - the echo request with a label of 1001. + [see LDP] for 192.168.1.1 (say label 1001), then to verify that label + 1001 does indeed reach an egress LSR that announced this prefix via + LDP, X can send an MPLS echo request with a FEC Stack TLV with one + FEC in it, namely of type LDP IPv4 prefix, with prefix + 192.168.1.1/32, and send the echo request with a label of 1001. Say LSR X wanted to verify that a label stack of <1001, 23456> is the - right label stack to use to reach a VPN IPv4 prefix of 10/8 in VPN - foo. Say further that LSR Y with loopback address 192.168.1.1 - announced prefix 10/8 with Route Distinguisher RD-foo-Y (which may in - general be different from the Route Distinguisher that LSR X uses in - its own advertisements for VPN foo), label 23456 and BGP nexthop - 192.168.1.1. Finally, suppose that LSR X receives a label binding of - 1001 for 192.168.1.1 via LDP. X has two choices in sending an MPLS - echo request: X can send an MPLS echo request with a FEC Stack TLV - with a single FEC of type VPN IPv4 prefix with a prefix of 10/8 and a - Route Distinguisher of RD-foo-Y. Alternatively, X can send a FEC - Stack TLV with two FECs, the first of type LDP IPv4 with a prefix of - 192.168.1.1/32 and the second of type of IP VPN with a prefix 10/8 - with Route Distinguisher of RD-foo-Y. In either case, the MPLS echo - request would have a label stack of <1001, 23456>. (Note: in this - example, 1001 is the "outer" label and 23456 is the "inner" label.) + right label stack to use to reach a VPN IPv4 prefix [see section + 3.2.5] of 10/8 in VPN foo. Say further that LSR Y with loopback + address 192.168.1.1 announced prefix 10/8 with Route Distinguisher + RD-foo-Y (which may in general be different from the Route Distin- + guisher that LSR X uses in its own advertisements for VPN foo), label + 23456 and BGP nexthop 192.168.1.1 [see BGP]. Finally, suppose that + LSR X receives a label binding of 1001 for 192.168.1.1 via LDP. X + has two choices in sending an MPLS echo request: X can send an MPLS + echo request with a FEC Stack TLV with a single FEC of type VPN IPv4 + prefix with a prefix of 10/8 and a Route Distinguisher of RD-foo-Y. + Alternatively, X can send a FEC Stack TLV with two FECs, the first of + type LDP IPv4 with a prefix of 192.168.1.1/32 and the second of type + of IP VPN with a prefix 10/8 with Route Distinguisher of RD-foo-Y. + In either case, the MPLS echo request would have a label stack of + <1001, 23456>. (Note: in this example, 1001 is the "outer" label and + 23456 is the "inner" label.) 3.2.1. LDP IPv4 Prefix - The value consists of four octets of an IPv4 prefix followed by one - octet of prefix length in bits; the format is given below. The IPv4 - prefix is in network byte order; if the prefix is shorter than 32 - bits, trailing bits SHOULD be set to zero. See [LDP] for an example - of a Mapping for an IPv4 FEC. + The IPv4 Prefix FEC is defined in [LDP]. When a LDP IPv4 prefix is + encoded in a label stack, the following format is used. The value + consists of four octets of an IPv4 prefix followed by one octet of + prefix length in bits; the format is given below. The IPv4 prefix is + in network byte order; if the prefix is shorter than 32 bits, trail- + ing bits SHOULD be set to zero. See [LDP] for an example of a Map- + ping for an IPv4 FEC. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.2. LDP IPv6 Prefix - The value consists of sixteen octets of an IPv6 prefix followed by - one octet of prefix length in bits; the format is given below. The - IPv6 prefix is in network byte order; if the prefix is shorter than - 128 bits, the trailing bits SHOULD be set to zero. See [LDP] for an - example of a Mapping for an IPv6 FEC. + The IPv6 Prefix FEC is defined in [LDP]. When a LDP IPv6 prefix is + encoded in a label stack, the following format is used. The value + consists of sixteen octets of an IPv6 prefix followed by one octet of + prefix length in bits; the format is given below. The IPv6 prefix is + in network byte order; if the prefix is shorter than 128 bits, the + trailing bits SHOULD be set to zero. See [LDP] for an example of a + Mapping for an IPv6 FEC. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 prefix | | (16 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.3. RSVP IPv4 LSP The value has the format below. The value fields are taken from - [RFC3209, sections 4.6.1.1 and 4.6.2.1]. + RFC3209, sections 4.6.1.1 and 4.6.2.1. See [RSVP-TE]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 tunnel end point address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | Tunnel ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extended Tunnel ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 tunnel sender address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.4. RSVP IPv6 LSP The value has the format below. The value fields are taken from - [RFC3209, sections 4.6.1.2 and 4.6.2.2]. + RFC3209, sections 4.6.1.2 and 4.6.2.2. See [RSVP-TE]. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 tunnel end point address | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | Tunnel ID | @@ -559,120 +555,143 @@ | IPv6 tunnel sender address | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Must Be Zero | LSP ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.5. VPN IPv4 Prefix - The value field consists of the Route Distinguisher advertised with - the VPN IPv4 prefix, the IPv4 prefix (with trailing 0 bits to make 32 - bits in all) and a prefix length, as follows: + VPN-IPv4 NLRI (Network Layer Routing Information) is defined in + [MPLS-L3-VPN]. This document uses the term VPN IPv4 prefix for a + VPN-IPv4 NLRI which has been advertised with an MPLS label in BGP. + See [BGP-LABEL]. + + When a VPN IPv4 prefix is encoded in a label stack, the following + format is used. The value field consists of the Route Distinguisher + advertised with the VPN IPv4 prefix, the IPv4 prefix (with trailing 0 + bits to make 32 bits in all) and a prefix length, as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Distinguisher | | (8 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.6. VPN IPv6 Prefix - The value field consists of the Route Distinguisher advertised with - the VPN IPv6 prefix, the IPv6 prefix (with trailing 0 bits to make - 128 bits in all) and a prefix length, as follows: + VPN-IPv6 NLRI (Network Layer Routing Information) is defined in + [MPLS-L3-VPN]. This document uses the term VPN IPv6 prefix for a + VPN-IPv6 NLRI which has been advertised with an MPLS label in BGP. + See [BGP-LABEL]. + + When a VPN IPv6 prefix is encoded in a label stack, the following + format is used. The value field consists of the Route Distinguisher + advertised with the VPN IPv6 prefix, the IPv6 prefix (with trailing 0 + bits to make 128 bits in all) and a prefix length, as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Distinguisher | | (8 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 prefix | | | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.7. L2 VPN Endpoint - The value field consists of a Route Distinguisher (8 octets), the - sender (of the ping)'s VE ID (2 octets), the receiver's VE ID (2 - octets), and an encapsulation type (2 octets), formatted as follows: + VPLS BGP NLRI and VE ID are defined in [VPLS]. This document uses + the simpler term L2 VPN endpoint when refering to a VPLS BGP NLRI. + When an L2 VPN endpoint is encoded in a label stack, the following + format is used. The value field consists of a Route Distinguisher (8 + octets), the sender (of the ping)'s VE ID (2 octets), the receiver's + VE ID (2 octets), and an encapsulation type (2 octets), formatted as + follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Route Distinguisher | | (8 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sender's VE ID | Receiver's VE ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Encapsulation Type | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.8. FEC 128 Pseudowire (Deprecated) - The value field consists of the remote PE address (the destination + FEC 128 and the term VC ID are defined in [PW-CONTROL]. When a FEC + 128 is encoded in a label stack, the following format is used. The + value field consists of the remote PE address (the destination address of the targeted LDP session), a VC ID and an encapsulation type, as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote PE Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | VC ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Encapsulation Type | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - This FEC will be deprecated, and is retained only for backward com- - patibility. Implementations of LSP ping SHOULD accept and process - this TLV, but SHOULD send LSP ping echo requests with the new TLV - (see next section), unless explicitly configured to use the old TLV. + This FEC is deprecated and is retained only for backward compatibil- + ity. Implementations of LSP ping SHOULD accept and process this TLV, + but SHOULD send LSP ping echo requests with the new TLV (see next + section), unless explicitly configured to use the old TLV. An LSR receiving this TLV SHOULD use the source IP address of the LSP echo request to infer the Sender's PE Address. 3.2.9. FEC 128 Pseudowire (Current) - The value field consists of the sender's PE address (the source - address of the targeted LDP session), the remote PE address (the des- - tination address of the targeted LDP session), a VC ID and an encap- - sulation type, as follows: + FEC 128 and the term VC ID are defined in [PW-CONTROL]. When a FEC + 128 is encoded in a label stack, the following format is used. The + value field consists of the sender's PE address (the source address + of the targeted LDP session), the remote PE address (the destination + address of the targeted LDP session), a VC ID and an encapsulation + type, as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sender's PE Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote PE Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | VC ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Encapsulation Type | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.10. FEC 129 Pseudowire - The Length of this TLV is 16 + AGI length + SAII length + TAII - length. Padding is used to make the total length a multiple of 4; - the length of the padding is not included in the Length field. + FEC 129 and the terms AII, AGI, SAII, and TAII are defined in [PW- + CONTROL]. When a FEC 129 is encoded in a label stack, the following + format is used. The Length of this TLV is 16 + AGI length + SAII + length + TAII length. Padding is used to make the total length a + multiple of 4; the length of the padding is not included in the + Length field. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sender's PE Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Remote PE Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PW Type | AGI Type | AGI Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -686,59 +705,63 @@ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AII Type | TAII Length | Value | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ TAII Value (contd.) ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value (cont.)| 0-3 octets of zero padding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.11. BGP Labeled IPv4 Prefix - The value field consists the IPv4 prefix (with trailing 0 bits to - make 32 bits in all), and the prefix length, as follows: + BGP labeled IPv4 prefixes are defined in [BGP-LABEL]. When a BGP + labeled IPv4 prefix is encoded in a label stack, the following format + is used. The value field consists the IPv4 prefix (with trailing 0 + bits to make 32 bits in all), and the prefix length, as follows: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 Prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.12. BGP Labeled IPv6 Prefix - The value consists of sixteen octets of an IPv6 prefix followed by - one octet of prefix length in bits; the format is given below. The - IPv6 prefix is in network byte order; if the prefix is shorter than - 128 bits, the trailing bits SHOULD be set to zero. + BGP labeled IPv6 prefixes are defined in [BGP-LABEL]. When a BGP + labeled IPv6 prefix is encoded in a label stack, the following format + is used. The value consists of sixteen octets of an IPv6 prefix fol- + lowed by one octet of prefix length in bits; the format is given + below. The IPv6 prefix is in network byte order; if the prefix is + shorter than 128 bits, the trailing bits SHOULD be set to zero. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv6 prefix | | (16 octets) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.13. Generic IPv4 Prefix The value consists of four octets of an IPv4 prefix followed by one octet of prefix length in bits; the format is given below. The IPv4 prefix is in network byte order; if the prefix is shorter than 32 bits, trailing bits SHOULD be set to zero. This FEC is used if the protocol advertising the label is unknown, or may change during the course of the LSP. An example is an inter-AS LSP that may be sig- - naled by LDP in one AS, by RSVP-TE in another AS, and by BGP between - the ASes, such as is common for inter-AS VPNs. + naled by LDP in one AS, by RSVP-TE [RSVP-TE] in another AS, and by + BGP between the ASes, such as is common for inter-AS VPNs. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IPv4 prefix | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Prefix Length | Must Be Zero | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3.2.14. Generic IPv6 Prefix @@ -784,22 +807,22 @@ 3.3. Downstream Mapping The Downstream Mapping object is a TLV which MAY be included in an echo request message. Only one Downstream Mapping object may appear in an echo request. The presence of a Downstream Mapping object is a request that Downstream Mapping objects be included in the echo reply. If the replying router is the destination of the FEC, then a Downstream Mapping TLV SHOULD NOT be included in the echo reply. Otherwise the replying router SHOULD include a Downstream Mapping object for each interface over which this FEC could be forwarded. - For a more precise definition of the notion of "downstream", see the - section named "Downstream". + For a more precise definition of the notion of "downstream", see sec- + tion 3.3.2, "Downstream Router and Interface". The Length is K + M + 4*N octets, where M is the Multipath Length, and N is the number of Downstream Labels. Values for K are found in the description of Address Type below. The Value field of a Down- stream Mapping has the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MTU | Address Type | DS Flags | @@ -818,22 +841,22 @@ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Downstream Label | Protocol | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Maximum Transmission Unit (MTU) - The MTU is the largest MPLS frame (including label stack) that fits - on the interface to the Downstream LSR. + The MTU is the size in octets of the largest MPLS frame (including + label stack) that fits on the interface to the Downstream LSR. Address Type The Address Type indicates if the interface is numbered or unnum- bered. It also determines the length of the Downstream IP Address and Downstream Interface fields. The resulting total for the initial part of the TLV is listed in the table below as "K Octets". The Address Type is set to one of the following values: Type # Address Type K Octets @@ -905,21 +928,21 @@ Unnumbered. For IPv4 it MUST set the Downstream IP Address to 224.0.0.2, for IPv6 the address MUST be set to FF02::2. In both cases the interface index MUST be set to 0. If an LSR receives an Echo Request packet with the all-routers multicast address, then this indicates that it MUST bypass both interface and label stack valida- tion, but return Downstream Mapping TLVs using the information pro- vided. Multipath Type - The following Mutipath Types are defined: + The following Multipath Types are defined: Key Type Multipath Information --- ---------------- --------------------- 0 no multipath Empty (Multipath Length = 0) 2 IP address IP addresses 4 IP address range low/high address pairs 8 Bit-masked IPv4 IP address prefix and bit mask address set 9 Bit-masked label set Label prefix and bit mask @@ -1160,21 +1183,22 @@ The label stack of the received echo request message. If any TTL values have been changed by this router, they SHOULD be restored. 3.7. Errored TLVs The following TLV is a TLV which MAY be included in an echo reply to inform the sender of an echo request of Mandatory TLVs either not supported by an implementation, or parsed and found to be in error. - The Value field contains the TLVs not understood encoded as sub-TLVs. + The Value field contains the TLVs that were not understood, encoded + as sub-TLVs. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 9 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Value | . . . . . . @@ -1515,27 +1540,28 @@ echo reply is received for a given Sequence Number (for a given UDP port and Handle), the Sequence Number for subsequent echo requests for that UDP port and Handle SHOULD be incremented. If the echo reply contains Downstream Mappings, and X wishes to traceroute further, it SHOULD copy the Downstream Mapping(s) into its next echo request(s) (with TTL incremented by one). 4.7. Issue with VPN IPv4 and IPv6 Prefixes - Typically, a LSP ping for a VPN IPv4 or IPv6 prefix is sent with a - label stack of depth greater than 1, with the innermost label having - a TTL of 1. This is to terminate the ping at the egress PE, before - it gets sent to the customer device. However, under certain circum- - stances, the label stack can shrink to a single label before the ping - hits the egress PE; this will result in the ping terminating prema- - turely. One such scenario is a multi-AS Carrier's Carrier VPN. + Typically, a LSP ping for a VPN IPv4 prefix or VPN IPv6 prefix is + sent with a label stack of depth greater than 1, with the innermost + label having a TTL of 1. This is to terminate the ping at the egress + PE, before it gets sent to the customer device. However, under cer- + tain circumstances, the label stack can shrink to a single label + before the ping hits the egress PE; this will result in the ping ter- + minating prematurely. One such scenario is a multi-AS Carrier's Car- + rier VPN. To get around this problem, one approach is for the LSR that receives such a ping to realize that the ping terminated prematurely, and send back error code 13. In that case, the initiating LSR can retry the ping after incrementing the TTL on the VPN label. In this fashion, the ingress LSR will sequentially try TTL values until it finds one that allows the VPN ping to reach the egress PE. 4.8. Non-compliant Routers @@ -1550,37 +1576,58 @@ the ALLROUTERs multicast address until a reply is received with a Downstream Mapping TLV. The Label Stack MAY be omitted from the Downstream Mapping TLV. Further the "Validate FEC Stack" flag SHOULD NOT be set until an echo reply packet with a Downstream Mapping TLV is received. 5. References Normative References + [BGP] Rekhter, Y. and T. Li, "A Border Gateway Protocol 4 + (BGP-4)", RFC 1771, March 1995. + [IANA] Narten, T. and H. Alvestrand, "Guidelines for IANA Considerations", BCP 26, RFC 2434, October 1998. [KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [LABEL-STACK] Rosen, E., et al, "MPLS Label Stack Encoding", RFC 3032, January 2001. Informative References + [BGP-LABEL] Rekhter, Y. and E. Rosen, "Carrying Label Information + in BGP-4", RFC 3107, May 2001. + [ICMP] Postel, J., "Internet Control Message Protocol", RFC 792. [LDP] Andersson, L., et al, "LDP Specification", RFC 3036, January 2001. + [MPLS-L3-VPN] Rekhter, Y. & Rosen, E., "BGP/MPLS IP VPNs", + draft-ietf-l3vpn-rfc2547bis-03.txt, work-in-progress. + + [PW-CONTROL] Martini, L. et al., "Pseudowire Setup and Maintenance + using the Label Distribution Protocol", + draft-ietf-pwe3-control-protocol-17.txt, + work-in-progress. + + [RSVP-TE] Awduche, D., et al., "RSVP-TE: Extensions to RSVP for + LSP Tunnels", RFC 3209, December 2001. + + [VPLS] Kompella, K. and Rekhter, Y., "Virtual Private LAN + Service", draft-ietf-l2vpn-vpls-bgp-05, + work-in-progress. + 6. Security Considerations Overall, the security needs for LSP Ping are are similar to those of ICMP Ping. There are at least two approaches to attacking LSRs using the mecha- nisms defined here. One is a Denial of Service attack, by sending MPLS echo requests/replies to LSRs and thereby increasing their work- load. The other is obfuscating the state of the MPLS data plane liveness by spoofing, hijacking, replaying or otherwise tampering @@ -1612,24 +1659,24 @@ The TCP and UDP port number 3503 has been allocated by IANA for LSP echo requests and replies. The following sections detail the new name spaces to be managed by IANA. For each of these name spaces, the space is divided into assignment ranges; the following terms are used in describing the procedures by which IANA allocates values: "Standards Action" (as defined in [IANA]); "Expert Review" and "Vendor Private Use". - Values from "Expert Review" ranges MUST be registered with IANA, and - MUST be accompanied by an Experimental RFC that describes the format - and procedures for using the code point; the actual assignment is - made during the IANA actions for the RFC. + Values from "Expert Review" ranges MUST be registered with IANA. The + request MUST be made via an Experimental RFC that describes the + format and procedures for using the code point; the actual assignment + is made during the IANA actions for the RFC. Values from "Vendor Private" ranges MUST NOT be registered with IANA; however, the message MUST contain an enterprise code as registered with the IANA SMI Network Management Private Enterprise Codes. For each name space that has a Vendor Private range, it must be specified where exactly the SMI Enterprise Code resides; see below for exam- ples. In this way, several enterprises (vendors) can use the same code point without fear of collision. 7.1. Message Types, Reply Modes, Return Codes @@ -1659,26 +1706,29 @@ 2 Reply via an IPv4/IPv6 UDP packet 3 Reply via an IPv4/IPv6 UDP packet with Router Alert 4 Reply via application level control channel Return Codes defined in this document are listed in section 3.1. 7.2. TLVs It is requested that IANA maintain a registry for the Type field of top-level TLVs as well as for any associated sub-TLVs. Note the - meaning of a sub-TLV is scoped by the TLV. The valid range for each - of these is 0-65535. Assignments in the range 0-16383 and - 32768-49161 are made via Standards Action as defined in [IANA]; - assignments in the range 16384-31743 and 49162-64511 are made via - Expert Review (see below); values in the range 31744-32746 and - 64512-65535 are for Vendor Private Use, and MUST NOT be allocated. + meaning of a sub-TLV is scoped by the TLV. The number spaces for the + sub-TLVs of various TLVs are independent. + + The valid range for TLVs and sub-TLVs is 0-65535. Assignments in the + range 0-16383 and 32768-49161 are made via Standards Action as + defined in [IANA]; assignments in the range 16384-31743 and + 49162-64511 are made via Expert Review as defined above; values in + the range 31744-32767 and 64512-65535 are for Vendor Private Use, and + MUST NOT be allocated. If a TLV or sub-TLV has a Type that falls in the range for Vendor Private Use, the Length MUST be at least 4, and the first four octets MUST be that vendor's SMI Enterprise Code, in network octet order. The rest of the Value field is private to the vendor. TLVs and sub-TLVs defined in this document are: Type Sub-Type Value Field ---- -------- ----------- @@ -1714,21 +1764,21 @@ This document is the outcome of many discussions among many people, that include Manoj Leelanivas, Paul Traina, Yakov Rekhter, Der-Hwa Gan, Brook Bailey, Eric Rosen, Ina Minei, Shivani Aggarwal and Vanson Lim. The description of the Multipath Information sub-field of the Down- stream Mapping TLV was adapted from text suggested by Curtis Vil- lamizar. -Authors' Address +Authors' Addresses Kireeti Kompella Juniper Networks 1194 N.Mathilda Ave Sunnyvale, CA 94089 Email: kireeti@juniper.net George Swallow Cisco Systems 1414 Massachusetts Ave, @@ -1737,21 +1787,21 @@ Email: swallow@cisco.com Copyright Notice Copyright (C) The Internet Society (2005). 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. Expiration Date - March 2006 + May 2006 Disclaimer of Validity 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 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.