Definition for BMP Multiple Peer Header
draft-liu-grow-bmp-multiple-peer-header-02
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Yisong Liu , Changwang Lin , Narasimha Prasad , Mukul Kumar Srivastava | ||
| Last updated | 2026-07-06 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
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| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-liu-grow-bmp-multiple-peer-header-02
GROW Working Group Y. Liu
Internet-Draft China Mobile
Intended status: Standards Track C. Lin
Expires: 7 January 2027 New H3C Technologies
P. Narasimha
Cisco Systems, Inc.
M. Srivastava
Hewlett Packard Enterprise
6 July 2026
Definition for BMP Multiple Peer Header
draft-liu-grow-bmp-multiple-peer-header-02
Abstract
This document proposes a format of multiple peer header for
aggregating BMP messages. It can be used to compress multiple BMP
messages with per-peer header into one aggregated BMP message, which
could reduce the amount of reported BMP messages and reduce network
overhead.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 7 January 2027.
Copyright Notice
Copyright (c) 2026 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
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and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. Multi-Peer Header Definition . . . . . . . . . . . . . . . . 3
4. Multi-Peer Header Message Format . . . . . . . . . . . . . . 3
5. Common Multi-Peer Header Format . . . . . . . . . . . . . . . 4
6. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Aggregation of Peer Down Notifications . . . . . . . . . 7
6.2. Optimized Route Monitoring and Route Mirroring for Common
Updates . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.3. Aggregation of Peer-up Notifications . . . . . . . . . . 8
6.4. Aggregation of Statistics Reports . . . . . . . . . . . . 9
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
9. Normative References . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
[RFC7854] defines the format of BMP messages including Initiation
message, Termination message, Route Monitoring message, Route
Mirroring message, Stats Reports message, and Peer Down/Up
Notification message. Except Initiation and Termination message, all
other BMP messages contain a Per-Peer Header. For BMP messages that
include a Per-Peer Header, referred to as BMP Per-Peer message, a
common format is defined as shown in Figure 1.
+------------------------------+
| Common Header |
+------------------------------+
| Per-Peer Header |
+------------------------------+
| BMP TLV |
+------------------------------+
Figure 1: Common Format of BMP Per-Peer Message
Depending on the BMP message type in Common Header, the BMP TLV
represents the corresponding BMP information.
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For multiple BMP Per-Peer messages, their BMP TLV may have both
identical and differing parts. When transmitting BMP Per-Peer
messages of the same type, these messages can be consolidated into a
single message, retaining only one copy of the identical parts to
reduce the message size, network overhead and improve overall network
performance.
This document defines a new BMP message type, referred to as Multi-
Peer Header message. It can be used to compress multiple BMP
messages of same type, each with a per-peer header, into a single
aggregated BMP message, which could reduce the amount of reported BMP
messages and reduce network overhead.
2. Requirements Language
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. Multi-Peer Header Definition
This section adds a new BMP message type for Multi-Peer Header, which
is populated in the message type field of the Common Header.
Message Type = TBD: Multi-Peer Header, Recommended value 7.
The Multi-Peer Header mechanism defined in this document serves as a
general framework for aggregating any BMP message type that includes
a Per-Peer Header. While specific optimizations and detailed formats
for particular message types (such as Statistics Reports) may be
defined in future extensions, this document establishes the
foundational structure that enables such optimizations.
4. Multi-Peer Header Message Format
This section defines the BMP Multi-Peer Header message format, as
shown in Figure 2.
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+-------------------------------------+
| Common Header (Type = TBD) |
+-------------------------------------+
| Common Multi-Peer Header |
~ ~
+-------------------------------------+
| Common Information |
~ ~
+-------------------------------------+
Figure 2: BMP Multi-Peer Header Message Format
In the BMP Multi-Peer Header message format, the Common Header is the
same as that defined in Section 4.1 of [RFC7854], the Common Multi-
Peer Header carries the distinct Per-Peer Information of the
corresponding BMP Per-Peer message, and the Common Information
comprises the identical part of the corresponding BMP Per-Peer
message.
The Common Multi-Peer Header format is defined in Section 5. The
Common Information format is defined differently based on various
Message Types in the Common Multi-Peer Header.
5. Common Multi-Peer Header Format
This section defines the format of the Common Multi-Peer Header in
BMP Multi-Peer Header message, as shown in Figure 3. The Multi-Peer
Message Type maps to existing BMP message types that include a Per-
Peer Header, as defined in [RFC7854] (such as Route Monitoring, Peer
Down Notification and Peer Up Notification).
The Common Multi-Peer Header can be used to construct a BMP Multi-
Peer Header message with various Multi-Peer Message Type. The Wild
Card Per-Peer Header is defined below and is similar to the Per-Peer
Header defined in Section 4.2 of [RFC7854]. The Per-Peer Information
is the different part of the corresponding BMP Per-Peer message.
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+--------------------------------------------------------+
| Multi-Peer Message Type (1 byte) |
+--------------------------------------------------------+
| Multi-Peer Message Length (2 byte) |
+--------------------------------------------------------+
| Wild Card Per-Peer Header 1 |
+--------------------------------------------------------+
| Per-Peer Information Length 1 (2 bytes) |
+--------------------------------------------------------+
| Per-Peer Information 1 |
~ ~
+--------------------------------------------------------+
| Wild Card Per-Peer Header N |
+--------------------------------------------------------+
| Per-Peer Information Length N (2 bytes) |
+--------------------------------------------------------+
| Per-Peer Information N |
~ ~
+--------------------------------------------------------+
Figure 3: Common Multi-Peer Header Format
In the Common Multi-Peer Header format, The Multi-Peer Message Type
definition is not included in this document, and it needs to be
defined according to the specific application of BMP message type.
The Multi-Peer Message Length is the length of Common Multi-Peer
Header in bytes (including all Wild Card Per-Peer Headers, Per-Peer
Information Lengths, and Per-Peer Information).
The Per-Peer Information format can vary based on the various Multi-
Peer Message Types. Each Wild Card Per-Peer Header could be followed
by its unique/distinct Per-Peer Information corresponding the BMP
Per-Peer Message. If no Per-Peer Information follows the Wild Card
Per-Peer Header, the corresponding Per-Peer Information Length MUST
be set to 0.
This document defines an Wild Card Per-Peer Header, that could be
used to apply to multiple peers, if desired. It is defined according
to Per-Peer Header of [RFC7854], as shown in Figure 4.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Type | Peer Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Distinguisher (present based on peer type) |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Address (16 bytes) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Mask (16 bytes) |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer AS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer BGP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp (seconds) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp (microseconds) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Wild Card Per-Peer Header Format
Compared with Per-Peer Header define in Section 4.2 of [RFC7854], the
Peer Mask is added to indicate the mask of Peer Address.
* When Peer Mask is 32 for IPv4 and 128 for IPv6 - the Peer Address
is used to indicate a specific peer (like the Peer Address of Per-
Peer Header in RFC 7854).
* When Peer Mask is 0 and Peer Address is 0 - the Wild Card Peer
Header applies to for all peers.
* Other non-zero values of Peer Mask - the Wild Card peer header
applies to multiple peers matching 'peer address' AND 'peer mask'
criteria.
6. Use Cases
The Multi-Peer Header mechanism defined in this document is designed
to optimize the transmission efficiency of BMP [RFC7854] by
aggregating messages that share common data across multiple peers.
This section outlines several practical use cases where applying the
Multi-Peer Header can significantly reduce network overhead and
improve processing scalability at the monitoring station.
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6.1. Aggregation of Peer Down Notifications
In scenarios where a monitoring router experiences a common failure
event (e.g., a link failure, maintenance action, or local software
restart) that causes simultaneous BGP session discontinuities with
multiple peers, multiple Peer Down Notification messages would
typically be generated. These Peer Down Notification messages can be
aggregated by using the Multi-Peer Header mechanism.
* How it works: The Common Information section of the Multi-Peer
Header Message would contain the common Reason code and any
associated Reason TLVs (e.g., descriptive text) that apply to all
affected sessions. Each distinct peer session is then represented
by a Wild Card Per-Peer Header (with its specific Peer Address,
AS, etc.) in the Common Multi-Peer Header. The Per-Peer
Information for each may be empty or contain peer-specific details
if needed.
* Benefit: Instead of sending N individual Peer Down Notification
messages (each with a full Per-Peer Header and repeated Reason
information), a single aggregated message is transmitted. This
drastically reduces the number of packets during failure storms,
easing the load on the network and the collection system.
6.2. Optimized Route Monitoring and Route Mirroring for Common Updates
Route Monitoring and Route Mirroring messages are the core BMP
message types that carry actual BGP UPDATE message. When similar BGP
UPDATE messages affect multiple peers, aggregation using the Multi-
Peer Header mechanism can significantly improve efficiency.
* How it works: The identical parts of BGP UPDATE PDUs (Protocol
Data Unit) form the Common Information section. The Common Multi-
Peer Header then lists the different parts of the set of peers
(identified by their Wild Card Per-Peer Headers) associated with
these BGP UPDATE PDUs.
* Benefit: Avoids transmitting multiple similar copies of the same,
potentially large, BGP UPDATE payload. This is particularly
useful for recording widespread routing events or anomalies in a
bandwidth-efficient manner.
* Notes:
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- Route Monitoring: This represents the most straightforward and
efficient use case for aggregation. Since standard Route
Monitoring messages primarily record which prefixes/paths were
advertised or withdrawn by which peer, aggregation does not
lose essential information.
- Route Mirroring: Implementers should be aware that this
aggregation loses the precise temporal ordering and per-peer
context that might be critical for some debugging purposes.
Its use should be configurable and appropriate to the
troubleshooting scenario.
6.3. Aggregation of Peer-up Notifications
In scenarios where a monitoring router establishes BGP sessions with
multiple peers that share common session parameters, Peer Up
Notification messages can be efficiently aggregated using the Multi-
Peer Header mechanism.
* How it works: The 'Common Information' section would contain the
shared parts of the Peer Up Notification, such as:
- Identical local and remote capabilities (if negotiated to be
the same across peers)
- Any other TLVs that are identical across the peer sessions
Each distinct peer session is represented by a 'Wild Card Per-Peer
Header' containing its specific addressing information (Peer
Address, Peer AS, etc.). Peer-specific details, such as local
address or unique TLVs, would be placed in the corresponding 'Per-
Peer Information' section.
* Benefit: When establishing sessions with a large group of
similarly configured peers (e.g., route reflector clients or peers
in a peer group), this aggregation avoids sending numerous nearly
identical Peer Up Notification messages. This significantly
reduces the initial message storm during network startup or
maintenance operations.
Note: The effectiveness of this aggregation depends on the degree of
commonality in session parameters. Peers within the same
administrative group or those configured with identical templates are
ideal candidates for this optimization.
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6.4. Aggregation of Statistics Reports
Statistics Reports messages, which convey various counter values per
peer, can also benefit from the Multi-Peer Header mechanism, albeit
with different trade-offs.
* How it works: The 'Common Information' would typically contain
only the Stat Type field (identifying which counter is being
reported). The actual counter values, which are almost always
peer-specific, are placed in the individual 'Per-Peer Information'
sections along with their respective 'Wild Card Per-Peer Headers'.
* Benefit: The primary optimization comes from header compression.
Instead of sending N separate BMP messages (each with its own
Common Header and Per-Peer Header), a single aggregated message
carries one Common Header and multiple concise Per-Peer entries.
This reduces:
- Network packet count (from N to 1)
- Processing overhead at both sender and receiver for handling
multiple message headers
- Total bandwidth consumption by eliminating redundant header
fields
* Notes:
- The aggregated message may become quite large if reporting
statistics for many peers, potentially exceeding the MTU and
causing fragmentation. Implementations SHOULD provide
mechanisms to limit the number of peers included in a single
aggregated message or to split large reports appropriately.
- Since counter values are rarely identical across peers, the
compression ratio for Statistics Reports is generally lower
than for other message types like Peer Down or Peer Up.
However, the reduction in protocol overhead remains
significant.
- The timing of statistics collection and reporting should be
considered. Aggregating near-simultaneous reports from
multiple peers maintains temporal coherence while reducing
message volume.
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7. Security Considerations
All security considerations for BMP [RFC7854]apply equally to
messages using the Multi-Peer Header mechanism.
8. IANA Considerations
This document requests that IANA assign a following new message type
in "BMP Message Types" registry of the BMP parameters namespace
(https://www.iana.org/assignments/bmp-parameters/bmp-
parameters.xhtml).
* Type = TBD (recommended value: 7): Multi-Peer Header
Additionally, this document creates a new registry for "Multi-Peer
Message Types" under the BMP parameters namespace. Future additions
to this registry require either Standards Action or IESG Approval.
9. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP
Monitoring Protocol (BMP)", RFC 7854,
DOI 10.17487/RFC7854, June 2016,
<https://www.rfc-editor.org/info/rfc7854>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
Authors' Addresses
Yisong Liu
China Mobile
China
Email: liuyisong@chinamobile.com
Changwang Lin
New H3C Technologies
China
Email: linchangwang.04414@h3c.com
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Prasad S. Narasimha
Cisco Systems, Inc.
Email: snprasad@cisco.com
Mukul Srivastava
Hewlett Packard Enterprise
10 Technology Park Dr
Westford, MA 01886
United States of America
Email: mukul.srivastava@hpe.com
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