Network Working Group E. Chen
Request for Comments: 5291 Cisco Systems
Category: Standards Track Y. Rekhter
Juniper Networks
August 2008
Network Working Group E. Chen
Request for Comments: 5291 Cisco Systems
Category: Standards Track Y. Rekhter
Juniper Networks
August 2008
Outbound Route Filtering Capability for BGP-4
BGP-4的出站路由过滤功能
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Abstract
摘要
This document defines a BGP-based mechanism that allows a BGP speaker to send to its BGP peer a set of Outbound Route Filters (ORFs) that the peer would use to constrain/filter its outbound routing updates to the speaker.
本文档定义了一种基于BGP的机制，该机制允许BGP演讲者向其BGP对等方发送一组出站路由筛选器（ORF），对等方将使用该筛选器约束/筛选其对演讲者的出站路由更新。
Currently, it is not uncommon for a BGP speaker [BGP-4] to receive, and then filter out some unwanted routes from its peers based on its local routing policy. Since the generation and transmission of routing updates by the sender, as well as the processing of routing updates by the receiver consume resources, it may be beneficial if the generation of such unwanted routing updates can be avoided in the first place.
目前，BGP演讲者[BGP-4]接收并根据其本地路由策略从其对等方过滤掉一些不需要的路由并不少见。由于发送方生成和传输路由更新以及接收方处理路由更新消耗资源，因此如果可以首先避免生成这种不需要的路由更新，则可能是有益的。
This document defines a BGP-based mechanism that allows a BGP speaker to send to its BGP peer a set of Outbound Route Filters (ORFs). The peer would then apply these filters, in addition to its locally configured outbound filters (if any), to constrain/filter its outbound routing updates to the speaker.
本文档定义了一种基于BGP的机制，允许BGP演讲者向其BGP对等方发送一组出站路由筛选器（ORF）。然后，除了本地配置的出站过滤器（如果有）之外，对等方还将应用这些过滤器，以约束/过滤对说话人的出站路由更新。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
This document uses the terms "Address Family Identifier (AFI)" and "Subsequent Address Family Identifier (SAFI)". In the context of this document, the meaning of these terms is the same as in [BGP-MP].
本文档使用术语“地址族标识符（AFI）”和“后续地址族标识符（SAFI）”。在本文件中，这些术语的含义与[BGP-MP]中的含义相同。
Conceptually, an ORF entry is a tuple of the form <AFI/SAFI, ORF-Type, Action, Match, ORF-value>; an ORF consists of one or more ORF entries that have a common AFI/SAFI and ORF-Type. An ORF is identified by <AFI/SAFI, ORF-Type>.
从概念上讲，ORF条目是一个元组，其形式为<AFI/SAFI，ORF类型，动作，匹配，ORF值>；ORF由一个或多个具有通用AFI/SAFI和ORF类型的ORF条目组成。ORF由<AFI/SAFI，ORF类型>标识。
The "AFI/SAFI" component provides a coarse granularity control by limiting the ORF to only the routes whose Network Layer Reachability Information (NLRI) matches the "AFI/SAFI" component of the ORF.
“AFI/SAFI”组件通过将ORF限制为仅其网络层可达性信息（NLRI）与ORF的“AFI/SAFI”组件匹配的路由来提供粗粒度控制。
The "ORF-Type" component determines the content of the ORF-value.
“ORF类型”组件确定ORF值的内容。
The "Action" component controls handling of the ORF Request by the remote peer. Action can be one of ADD, REMOVE, REMOVE-ALL. ADD adds an ORF entry to the ORF on the remote peer; REMOVE deletes a previously installed ORF entry on the remote peer; REMOVE-ALL deletes the previously installed entries in the specified ORF on the remote peer.
“操作”组件控制远程对等方对ORF请求的处理。操作可以是添加、删除、全部删除。ADD将ORF条目添加到远程对等机上的ORF中；REMOVE删除远程对等机上以前安装的ORF条目；REMOVE-ALL删除远程对等机上指定ORF中以前安装的条目。
The "Match" component is used to support matching granularity on a per ORF entry basis. It can be either PERMIT or DENY. The semantics of PERMIT is to ask the peer to pass updates for the set of routes that match the ORF entry. The semantics of DENY is to ask the peer not to pass updates for the set of routes that match the ORF entry.
“匹配”组件用于支持基于每个ORF条目的匹配粒度。它可以是允许或拒绝。PERMIT的语义是要求对等方传递与ORF条目匹配的路由集的更新。DENY的语义是要求对等方不要传递与ORF条目匹配的路由集的更新。
When an ORF is defined, an ORF-specific matching rule MUST be specified so that there is no ambiguity regarding which ORF entry is considered as the matching entry in the ORF when a route is passed through the ORF.
定义ORF时，必须指定特定于ORF的匹配规则，以确保当路线通过ORF时，ORF中的哪个ORF条目被视为匹配条目不存在歧义。
ORF entries are carried in the BGP ROUTE-REFRESH message [BGP-RR].
ORF条目包含在BGP路由刷新消息[BGP-RR]中。
A BGP speaker can distinguish an incoming ROUTE-REFRESH message that carries one or more ORF entries from an incoming plain ROUTE-REFRESH message by using the Message Length field in the BGP message header.
通过使用BGP消息头中的消息长度字段，BGP扬声器可以将携带一个或多个ORF条目的传入路由刷新消息与传入普通路由刷新消息区分开来。
A single ROUTE-REFRESH message MAY carry multiple ORF entries in one or more ORFs, as long as all these entries share the same AFI/SAFI.
一条路由刷新消息可以在一个或多个ORF中携带多个ORF条目，只要所有这些条目共享相同的AFI/SAFI。
From the encoding point of view, each ORF entry consists of a common part and type-specific part, as shown in Figures 1 and 2.
从编码的角度来看，每个ORF条目由一个公共部分和一个特定类型的部分组成，如图1和图2所示。
The common part consists of <AFI/SAFI, ORF-Type, Action, Match>, and is encoded as follows:
公共部分由<AFI/SAFI，ORF类型，动作，匹配>，编码如下：
The AFI/SAFI component of an ORF entry is encoded in the AFI/SAFI field of the ROUTE-REFRESH message.
ORF条目的AFI/SAFI组件编码在ROUTE-REFRESH消息的AFI/SAFI字段中。
Following the AFI/SAFI component is the one-octet When-to-refresh field. The value of this field can be either IMMEDIATE (0x01) or DEFER (0x02). The semantics of IMMEDIATE and DEFER are discussed in the "Operation" section of this document.
AFI/SAFI组件后面是“何时刷新”字段的一个八位字节。此字段的值可以是立即（0x01）或延迟（0x02）。立即和延迟的语义将在本文档的“操作”部分讨论。
Following the When-to-refresh field is a collection of one or more ORFs, grouped by ORF-Type.
“何时刷新”字段后面是一个或多个ORF的集合，按ORF类型分组。
The ORF-Type component is encoded as a one-octet field.
ORF类型组件编码为一个八位字节字段。
The "Length of ORF entries" component is a two-octet field that contains the total length (in octets) of the ORF entries that follows for the specified ORF type.
“ORF条目长度”组件是一个两个八位字节的字段，其中包含指定ORF类型的ORF条目的总长度（以八位字节为单位）。
+--------------------------------------------------+
| Address Family Identifier (2 octets) |
+--------------------------------------------------+
| Reserved (1 octet) |
+--------------------------------------------------+
| Subsequent Address Family Identifier (1 octet) |
+--------------------------------------------------+
| When-to-refresh (1 octet) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Length of ORF entries (2 octets) |
+--------------------------------------------------+
| First ORF entry (variable) |
+--------------------------------------------------+
| Second ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| N-th ORF entry (variable) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Length of ORF entries (2 octets) |
+--------------------------------------------------+
| First ORF entry (variable) |
+--------------------------------------------------+
| Second ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| N-th ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
+--------------------------------------------------+
| Address Family Identifier (2 octets) |
+--------------------------------------------------+
| Reserved (1 octet) |
+--------------------------------------------------+
| Subsequent Address Family Identifier (1 octet) |
+--------------------------------------------------+
| When-to-refresh (1 octet) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Length of ORF entries (2 octets) |
+--------------------------------------------------+
| First ORF entry (variable) |
+--------------------------------------------------+
| Second ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| N-th ORF entry (variable) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Length of ORF entries (2 octets) |
+--------------------------------------------------+
| First ORF entry (variable) |
+--------------------------------------------------+
| Second ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| N-th ORF entry (variable) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
Figure 1: Carrying ORF Entries in the ROUTE-REFRESH Message
图1：在ROUTE-REFRESH消息中携带ORF条目
The rest of the components in the common part are encoded in the first octet of each ORF-entry (from the most significant to the least significant bit) as shown in Figure 2:
公共部分中的其余组件编码在每个ORF条目的第一个八位字节中（从最高有效位到最低有效位），如图2所示：
Action is a two-bit field. The value of this field is 0 for ADD, 1 for REMOVE, and 2 for REMOVE-ALL.
动作是一个两位字段。此字段的值为0表示添加，1表示删除，2表示全部删除。
Match is a one-bit field. The value of this field is 0 for PERMIT and 1 for DENY. This field is significant only when the value of the Action field is either ADD or REMOVE.
匹配是一个一位字段。此字段的值为0表示允许，1表示拒绝。仅当“操作”字段的值为“添加”或“删除”时，此字段才有效。
Reserved is a 5-bit field. It is set to 0 on transmit and ignored on receipt.
保留是一个5位字段。传输时设置为0，接收时忽略。
+---------------------------------+
| Action (2 bit) |
+---------------------------------+
| Match (1 bit) |
+---------------------------------+
| Reserved (5 bits) |
+---------------------------------+
| Type specific part (variable) |
+---------------------------------+
+---------------------------------+
| Action (2 bit) |
+---------------------------------+
| Match (1 bit) |
+---------------------------------+
| Reserved (5 bits) |
+---------------------------------+
| Type specific part (variable) |
+---------------------------------+
Figure 2: ORF Entry Encoding
图2：ORF条目编码
When the Action component of an ORF entry specifies REMOVE-ALL, the entry consists of only the common part.
当ORF条目的Action组件指定REMOVE-ALL时，该条目只包含公共部分。
A BGP speaker that is willing to receive ORF entries from its peer, or a BGP speaker that would like to send ORF entries to its peer, advertises this to the peer by using the Outbound Route Filtering Capability, as described below.
愿意从其对等方接收ORF条目的BGP演讲者，或希望向其对等方发送ORF条目的BGP演讲者，通过使用出站路由过滤功能向对等方播发ORF条目，如下所述。
The Outbound Route Filtering Capability is a new BGP Capability [BGP-CAP] defined as follows:
出站路由过滤功能是一种新的BGP功能[BGP-CAP]，定义如下：
Capability code: 3
能力代码：3
Capability length: variable
能力长度：可变
Capability value: one or more of the entries as shown in Figure 3.
能力值：一个或多个条目，如图3所示。
+--------------------------------------------------+
| Address Family Identifier (2 octets) |
+--------------------------------------------------+
| Reserved (1 octet) |
+--------------------------------------------------+
| Subsequent Address Family Identifier (1 octet) |
+--------------------------------------------------+
| Number of ORFs (1 octet) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Send/Receive (1 octet) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Send/Receive (1 octet) |
+--------------------------------------------------+
+--------------------------------------------------+
| Address Family Identifier (2 octets) |
+--------------------------------------------------+
| Reserved (1 octet) |
+--------------------------------------------------+
| Subsequent Address Family Identifier (1 octet) |
+--------------------------------------------------+
| Number of ORFs (1 octet) |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Send/Receive (1 octet) |
+--------------------------------------------------+
| ... |
+--------------------------------------------------+
| ORF Type (1 octet) |
+--------------------------------------------------+
| Send/Receive (1 octet) |
+--------------------------------------------------+
Figure 3: Outbound Route Filtering Capability Encoding
图3：出站路由过滤能力编码
The use and meaning of these fields are as follows:
这些字段的用法和含义如下：
Address Family Identifier (AFI):
地址族标识符（AFI）：
This field is the same as the one used in [BGP-MP].
此字段与[BGP-MP]中使用的字段相同。
Subsequent Address Family Identifier (SAFI):
后续地址系列标识符（SAFI）：
This field is the same as the one used in [BGP-MP].
此字段与[BGP-MP]中使用的字段相同。
Number of ORF Types:
ORF类型的数量：
This field contains the number of Filter Types to be listed in the following fields.
此字段包含要在以下字段中列出的过滤器类型数。
ORF Type:
ORF类型：
This field contains the value of an ORF Type.
此字段包含ORF类型的值。
Send/Receive:
发送/接收：
This field indicates whether the sender is (a) willing to receive ORF entries from its peer (value 1), (b) would like to send ORF entries to its peer (value 2), or (c) both (value 3) for the ORF Type.
此字段表示发送方是否（a）愿意从其对等方接收ORF条目（值1），（b）希望向其对等方发送ORF条目（值2），或（c）对于ORF类型，是否同时发送ORF条目（值3）。
A BGP speaker that is willing to receive ORF entries from its peer, or would like to send ORF entries to its peer SHOULD advertise the Outbound Route Filtering Capability to the peer using BGP Capabilities advertisement [BGP-CAP].
愿意从其对等方接收ORF条目或希望向其对等方发送ORF条目的BGP演讲者应使用BGP功能公告[BGP-CAP]向对等方公告出站路由过滤功能。
A BGP speaker that implements the Outbound Route Filtering Capability MUST support the BGP ROUTE-REFRESH message, as defined in [BGP-RR]. A BGP speaker that advertises the Outbound Route Filtering Capability to a peer using BGP Capabilities advertisement [BGP-CAP] does not have to advertise the BGP Route Refresh Capability to that peer.
实现出站路由过滤功能的BGP扬声器必须支持[BGP-RR]中定义的BGP Route-REFRESH消息。使用BGP功能公告[BGP-CAP]向对等方公告出站路由过滤功能的BGP扬声器不必向该对等方公告BGP路由刷新功能。
Consider a BGP speaker that advertises the Outbound Route Filtering Capability indicating its willingness to receive a particular set of <AFI/SAFI, ORF-Type> from its peer, and that receives the Outbound Route Filtering Capability indicating the desire of the peer to send a particular set <AFI/SAFI, ORF-Type> to the speaker. If for a given AFI/SAFI the intersection between these two sets is non-empty, the speaker SHOULD NOT advertise to the peer any routes with that AFI/SAFI prior to receiving from the peer any ROUTE-REFRESH message carrying that AFI/SAFI, where the message could be either without any ORF entries, or with one or more ORF entry and the When-to-refresh field set to IMMEDIATE. If, on the other hand, for a given AFI/SAFI the intersection between these two sets is empty, the speaker MUST follow normal BGP procedures.
考虑一个BGP扬声器，它宣传出站路由过滤能力，表明它愿意从它的对等点接收一组特定的<AFI/SAFI，ORF类型>，并且接收出线路由过滤能力，指示对等点发送特定的集合AFI/SAFI，ORF类型>到扬声器的愿望。如果对于给定的AFI/SAFI，这两个集合之间的交集是非空的，则演讲者在从对等方接收到携带该AFI/SAFI的任何路由刷新消息之前，不应向对等方通告该AFI/SAFI的任何路由，其中该消息可以没有任何ORF条目，或将一个或多个ORF条目和“何时刷新”字段设置为“立即”。另一方面，如果对于给定的AFI/SAFI，这两个集合之间的交点为空，则扬声器必须遵循正常的BGP程序。
A BGP speaker may send a ROUTE-REFRESH message with one or more ORF entries to its peer only if the peer advertises to the speaker the Outbound Route Filtering Capability indicating its willingness to receive ORF entries from the speaker, and the speaker advertises to the peer the Outbound Route Filtering Capability indicating its
BGP说话人可向其对等方发送带有一个或多个ORF条目的路由刷新消息，前提是对等方向说话人播发出站路由过滤能力，指示其愿意从说话人接收ORF条目，并且说话人向对等方播发出站路由过滤能力，指示其接收ORF条目
desire to send ORF entries to the peer. The message may contain only ORF entries of <AFI/SAFI, ORF-type> that the peer is willing to receive, as advertised to the speaker in the Outbound Route Filtering Capability.
希望向对等方发送ORF条目。消息可能仅包含对等方愿意接收的<AFI/SAFI，ORF type>的ORF条目，如在出站路由过滤功能中通告给说话人的。
When a BGP speaker receives a ROUTE-REFRESH message with one or more ORF entries from its peer, then the speaker performs the following actions. If an <AFI/SAFI, ORF-type> carried by the message does not match <AFI/SAFI, ORF-type> that the speaker is willing to receive from the peer (as advertised to the peer in the Outbound Route Filtering Capability), the specified ORF entries in the message are ignored. Otherwise, the speaker modifies the specified ORF previously received, according to the ORF entries carried in the message. If any of the fields of an ORF entry in the message contains an unrecognized value, the whole specified ORF previously received is removed.
当BGP演讲者从其对等方接收到包含一个或多个ORF条目的路由刷新消息时，演讲者将执行以下操作。如果消息携带的<AFI/SAFI，ORF type>与说话人愿意从对等方接收的<AFI/SAFI，ORF type>不匹配（如在出站路由过滤功能中通告给对等方），则消息中指定的ORF条目将被忽略。否则，说话人根据消息中的ORF条目修改先前接收到的指定ORF。如果消息中某个ORF条目的任何字段包含无法识别的值，则先前收到的整个指定ORF将被删除。
If the Action component of an ORF entry is REMOVE, but the ORF previously received does not contain the specified entry, the ORF entry in the message is ignored.
如果ORF条目的操作组件为REMOVE，但之前收到的ORF不包含指定条目，则忽略消息中的ORF条目。
ORF entries with either REMOVE or REMOVE-ALL cannot remove locally configured outbound route filters.
带有REMOVE或REMOVE-ALL的ORF条目无法删除本地配置的出站路由筛选器。
If the When-to-refresh indicates IMMEDIATE, then after processing all the ORF entries carried in the message the speaker re-advertises to the peer routes from the Adj-RIB-Out associated with the peer that have the same AFI/SAFI as what is carried in the message, and taking into account all the ORF entries for that AFI/SAFI received from the peer. The speaker MUST re-advertise all the routes that have been affected by the ORF entries carried in the message, but MAY also re-advertise the routes that have not been affected by the ORF entries carried in the message.
如果“何时刷新”指示立即刷新，则在处理消息中携带的所有ORF条目后，演讲者从与具有与消息中携带的AFI/SAFI相同的AFI/SAFI的对等方关联的Adj RIB Out向对等方重新播发，并考虑从对等方接收的该AFI/SAFI的所有ORF条目。演讲者必须重新公布所有受消息中所载ORF条目影响的路由，但也可以重新公布未受消息中所载ORF条目影响的路由。
If the When-to-refresh indicates DEFER, then after processing all the ORF entries carried in the message the speaker defers re-advertisement to the peer routes from the Adj-RIB-Out associated with the peer that have the same AFI/SAFI as what is carried in the message, and taking into account all the ORF entries received from the peer until the speaker receives a subsequent ROUTE-REFRESH message for the same AFI/SAFI either without any ORF entries, or with one or more ORF entries and When-to-refresh set to IMMEDIATE.
如果“何时刷新”指示延迟，则在处理消息中携带的所有ORF条目后，说话人延迟从与具有与消息中携带的相同AFI/SAFI的对等方相关联的Adj RIB Out向对等方路由重新播发，以及考虑从对等方接收到的所有ORF条目，直到说话人接收到针对相同AFI/SAFI的后续路由刷新消息，该消息或者没有任何ORF条目，或者具有一个或多个ORF条目，并且何时刷新设置为立即。
If the speaker receives from the peer a ROUTE-REFRESH message without any ORF entries, then the speaker sends to the peer all routes from the Adj-RIB-Out associated with the peer whose AFI/SAFI is the same as what is carried in the message and taking into account the ORFs (if any) previously received from the peer.
如果说话人从对等方接收到一条没有任何ORF条目的路由刷新消息，则说话人将来自Adj RIB Out的所有路由发送给对等方，该Adj RIB Out与该对等方的AFI/SAFI与消息中携带的相同，并考虑到先前从对等方接收到的ORF（如果有）。
The set of ORF entries that the speaker sends to the peer expresses the speaker's local preference, that the peer may or may not decide to honor.
说话人发送给对等方的一组ORF条目表示说话人的本地偏好，对等方可能会也可能不会决定遵守。
During a single BGP session, the speaker MAY pass multiple ORF entries to the peer.
在单个BGP会话期间，演讲者可以将多个ORF条目传递给对等方。
After a BGP speaker makes changes to the ORF entries previously sent to a peer, the speaker MUST send to the peer the updated ORF entries with either (a) When-to-refresh set to IMMEDIATE, or (b) When-to-refresh set to DEFER followed by a plain ROUTE-REFRESH message. The latter MUST be used by the speaker when there are other policy changes (in addition to the ORF entries) that require the peer to re-advertise all the routes.
BGP演讲者对先前发送给对等方的ORF条目进行更改后，演讲者必须向对等方发送更新的ORF条目，其中包括（a）何时刷新设置为立即，或（b）何时刷新设置为延迟，然后发送普通路由刷新消息。当有其他策略更改（除ORF条目外）需要对等方重新公布所有路由时，演讲者必须使用后者。
The lifetime of an ORF is the duration of the BGP session during which the ORF is exchanged.
ORF的生存期是交换ORF的BGP会话的持续时间。
An ORF is removed when the last ORF entry is removed (either via REMOVE-ALL, or via a sequence of REMOVE).
当最后一个ORF条目被删除时，ORF被删除（通过REMOVE-ALL或通过REMOVE序列）。
If a particular route maintained by a BGP speaker does not match any of the ORF entries of any of the (non-empty) ORFs associated with a particular peer, then this route SHOULD NOT be advertised to the peer.
如果BGP演讲者维护的特定路由与与特定对等方关联的任何（非空）ORF的任何ORF条目不匹配，则不应向该对等方通告该路由。
If a BGP speaker maintains multiple ORFs of different ORF-Types for a particular peer, then the decision by the speaker to advertise a route to the peer is determined by passing the route through each such ORF, and combining the results (combining of PERMIT and DENY results in DENY).
如果BGP演讲者为特定对等方维护多个不同ORF类型的ORF，则演讲者向对等方通告路由的决定通过将路由通过每个这样的ORF并组合结果来确定（在DENY中组合许可和拒绝结果）。
This document defines a new BGP Capability - Outbound Route Filtering Capability. The Capability Code for the Outbound Route Filtering Capability is 3.
本文档定义了一种新的BGP功能—出站路由过滤功能。出站路由过滤功能的功能代码为3。
As specified in this document, an ORF entry contains the ORF-Type field for which IANA has created and now maintains a registry entitled "BGP Outbound Route Filtering (ORF) Types".
如本文档所述，ORF条目包含IANA为其创建的ORF类型字段，现在维护一个名为“BGP出站路由筛选（ORF）类型”的注册表。
IANA maintains and registers values for ORF-Type field as follows:
IANA维护并注册ORF类型字段的值，如下所示：
- ORF-Type value 0 is reserved.
- ORF类型值0是保留的。
- ORF-Type values 1 through 63 are to be assigned by IANA using either the Standards Action process defined in RFC 5226 [RFC5226], or the Early IANA Allocation process defined in RFC 4020 [RFC4020].
- ORF类型值1至63由IANA使用RFC 5226[RFC5226]中定义的标准行动流程或RFC 4020[RFC4020]中定义的早期IANA分配流程进行分配。
- ORF-Type values 64 through 127 are to be assigned by IANA, using the "First Come First Served" policy defined in RFC 5226 [RFC5226].
- 使用RFC 5226[RFC5226]中定义的“先到先得”策略，IANA将分配ORF类型值64到127。
- ORF-Type values 128 through 255 are vendor-specific, and values in this range are not to be assigned by IANA.
- ORF类型值128到255是特定于供应商的，此范围内的值不由IANA分配。
The management objects for BGP ORFs will be defined separately, outside this document. However, it is suggested that the following management objects be defined:
BGP ORF的管理对象将在本文件之外单独定义。但是，建议定义以下管理对象：
The ORF Capability object, which describes the ORF Capability exchanged over a BGP session, should include the ORF types and the Send/Receive values advertised and received for a BGP peer.
ORF能力对象描述通过BGP会话交换的ORF能力，应包括为BGP对等方播发和接收的ORF类型和发送/接收值。
The ORF entry object should contain the ORF entries of each ORF sent and received for a BGP peer.
ORF条目对象应包含BGP对等方发送和接收的每个ORF的ORF条目。
This extension to BGP does not change the underlying security issues [BGP-4].
BGP的此扩展不会改变基础安全问题[BGP-4]。
Some of the material in the document is adapted from a proposal for selective updates by Yakov Rekhter, Kannan Varadhan, and Curtis Villamizar.
文件中的一些材料是根据雅科夫·雷克特、坎南·瓦拉丹和柯蒂斯·维拉米扎的选择性更新建议改编而成的。
[BGP-4] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.
[BGP-4]Rekhter，Y.，Ed.，Li，T.，Ed.，和S.Hares，Ed.，“边境网关协议4（BGP-4）”，RFC 42712006年1月。
[BGP-MP] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, "Multiprotocol Extensions for BGP-4", RFC 4760, January 2007.
[BGP-MP]Bates，T.，Chandra，R.，Katz，D.，和Y.Rekhter，“BGP-4的多协议扩展”，RFC 4760，2007年1月。
[BGP-CAP] Chandra, R. and J. Scudder, "Capabilities Advertisement with BGP-4", RFC 3392, November 2002.
[BGP-CAP]Chandra，R.和J.Scudder，“BGP-4的能力广告”，RFC 3392，2002年11月。
[BGP-RR] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918, September 2000.
[BGP-RR]Chen，E.“BGP-4的路由刷新能力”，RFC 2918，2000年9月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC4020] Kompella, K. and A. Zinin, "Early IANA Allocation of Standards Track Code Points", BCP 100, RFC 4020, February 2005.
[RFC4020]Kompella，K.和A.Zinin，“早期IANA标准轨道代码点分配”，BCP 100，RFC 4020，2005年2月。
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
[RFC5226]Narten，T.和H.Alvestrand，“在RFCs中编写IANA注意事项部分的指南”，BCP 26，RFC 5226，2008年5月。
Authors' Addresses
作者地址
Enke Chen Cisco Systems, Inc. 170 W. Tasman Dr. San Jose, CA 95134
Enke Chen思科系统公司170 W.Tasman Dr.San Jose，CA 95134
Email: enkechen@cisco.com
Email: enkechen@cisco.com
Yakov Rekhter Juniper Networks 1194 N. Mathilda Ave Sunnyvale, CA 94089
加利福尼亚州桑尼维尔马蒂尔达大道北1194号雅科夫·雷克特·朱尼珀网络公司，邮编94089
Email: yakov@juniper.net
Email: yakov@juniper.net
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