GROW N. Geng
Internet-Draft S. Zhuang
Intended status: Standards Track Huawei Technologies
Expires: 4 September 2025 3 March 2025
Synchronizing BMP Monitoring Options and State
draft-geng-grow-bmp-sync-options-and-state-00
Abstract
This document proposes methods to facilitate correction of BGP
Routing Information Base inconsistencies in a non-disruptive manner
from the BMP Sender to the BMP Collector.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. BMP Route-Refresh message . . . . . . . . . . . . . . . . . . 2
2.1. Example of using BMP Route-Refresh messages . . . . . . . 3
3. BMP Monitoring Options message . . . . . . . . . . . . . . . 4
3.1. Example of using BMP Monitoring Options message . . . . . 6
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
5. Security Considerations of Inter-domain SPD . . . . . . . . . 8
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
8.1. Normative References . . . . . . . . . . . . . . . . . . 8
8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
The generation of BGP Adj-RIB-In, Loc-RIB and Adj-RIB-Out comes from
BGP route exchange and route policy processing. BGP Monitoring
Protocol (BMP) provides the monitoring of BGP Adj-RIB-In [RFC7854],
BGP Loc-RIB [RFC9069] and BGP Adj-RIB-Out [RFC8671]. The RIB view
inconsistency may occur between the BMP sender and BMP collector due
to message loss, network flapping, instability, and faults. In this
document, we define methods to facilitate correction of BGP Routing
Information Base (RIB) inconsistencies in a non-disruptive manner
from the BMP Sender to the BMP Collector.
1.1. 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.
2. BMP Route-Refresh message
This document defines a new BMP Route-Refresh message type (TBD1)
that is used to synchronize the RIB view from the BMP sender to the
BMP collector. Following the common BMP header and per-peer header
is a Route-Refresh PDU. The Route-Refresh PDU is a ROUTE-REFRESH
message defined in [RFC2918] and updated by [RFC7313], and its format
is as follows:
Type: 5 - ROUTE-REFRESH
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Message Format: One <AFI, Sub-Type, SAFI> tuple encoded as:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI | Sub-Type | SAFI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: ROUTE-REFRESH Message
The meaning, usage, and encoding of this <AFI, Sub-Type, SAFI> tuple
are defined in [RFC2918] and updated by [RFC7313] as follows:
* AFI - Address Family Identifier (2 octets)
* Sub-Type - Message Subtype (1 octet):
- 0 - Normal route refresh request [RFC2918] with/without
Outbound Route Filtering (ORF) [RFC5291]
- 1 - Demarcation of the beginning of a route refresh (BoRR)
operation
- 2 - Demarcation of the ending of a route refresh (EoRR)
operation
- 255 - Reserved
* SAFI - Subsequent Address Family Identifier (1 octet).
2.1. Example of using BMP Route-Refresh messages
The sequences of BMP messages transmissions shown as follows:
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BMP Sender BMP Collector
~ ~
| ------- BMP BoRR ---------> | Sender notifies BoRR operation
| |
| | Collector marks the routes of
| | the specific RIB view as
| | stale/historical or purges
| | them directly
| |
| ------- BMP RM Msg.-------> | Sender sends zero or more
| --------........----------> | Route Monitoring Messages for
| ------- BMP RM Msg.-------> | the specific RIB view
| | Collector uses the new routes
| | to update the stale/historical
| | routes
| ------- BMP EoRR ---------> | Sender notifies EoRR operation
| |
| | Collector purges the routes
| | remaining the stale/historical
| | state
| |
~ ~
Figure 2: An example of using BMP Route-Refresh messages
3. BMP Monitoring Options message
This document defines a new Monitoring Options (MO) message type
(TBD2) that is used to synchronize the monitoring options from the
BMP sender to BMP collector. Following the common BMP header and
per-peer header is a BMP Monitoring Options PDU. The BMP Monitoring
Options PDU is defined 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | SubType |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI1 | Res. | SAFI1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI2 | Res. | SAFI2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFIn | Res. | SAFIn |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Figure 3: The BMP Monitoring Options PDU
Where:
* Type - 2 octets, It indicates as follows:
- 1 - Adj-RIB-In
- 2 - Adj-RIB-Out
- 3 - Loc-RIB
* SubType - 2 octets, It indicates as follows:
- 1 - pre-policy
- 2 - post-policy
* Flags - 2 octets, the least significant bit of Flags Indicates
whether the options are enabled or disabled, and other bits are
reserved.
* Length - 2 octets
* The list of (AFI, SAFI) follows the Length field.
- AFI - Address Family Identifier (2 octets)
- SAFI - Subsequent Address Family Identifier (1 octet)
- Res. - Reserved field that will be set Zero (1 octet)
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stat Type 1 | Stat Type 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ...... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Stat Type n-1 | Stat Type n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: The BMP Monitoring Options PDU
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Where:
* Type - 2 octets, It indicates as follows:
- 4 - Stats
* Flags - 2 octets, the least significant bit of Flags Indicates
whether the options are enabled or disabled, and other bits are
reserved.
* Length - 2 octets
* The list of Stat Types follows the Length field.
- Stat Type - Defines the type of the statistic [RFC7854]. (2
octets)
3.1. Example of using BMP Monitoring Options message
In the following scenario, a BGP session is established between
Router1 and Router2, and IPv4 unicast, IPv4 multicast, and IPv4
labeled unicast address families are enabled on both the BGP
speakers. The two BGP speakers exchange IPv4 unicast, IPv4
multicast, and IPv4 labeled unicast address family routes. Router1
as the BMP Sender sends BMP messages to the BMP Collector.
BMP Collector
|
|
| BGP Session
Router1(BMP Sender)----------------Router2
Figure 5: BGP Monitoring Example
Sender initiates the BMP protocol with the Collector:
BMP Sender BMP Collector
~ ~
|------ Initial Export -------> | Sender Sends Route Monitoring
| | messages for IPv4 unicast,
| | IPv4 multicast and IPv4
| | labeled unicast address
| | families
| | Collector stores the RIB info
| | for the Sender
Figure 6: Sender sends Initial Export to Collector
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Sender disabled the monitoring on IPv4 multicast address family:
BMP Sender BMP Collector
|-MO with(AFI 1/SAFI 2) disable-| Sender sends an MO message
| | to Collector
| | Collector purges the IPv4
| | multicast RIB view of the
| | specific BGP peer
Figure 7: Sender disabled the monitoring on IPv4 multicast
address family
Sender disabled the monitoring on IPv4 labeled unicast address
family:
BMP Sender BMP Collector
|-MO with(AFI 1/SAFI 4) disable-| Sender sends an MO message
| | to Collector
| | Collector purges the IPv4
| | labeled unicast RIB view
| | of the specific BGP peer
| |
Figure 8: Sender disabled the monitoring on IPv4 labeled unicast
address family
Sender enabled the monitoring on IPv4 multicast address family:
BMP Sender BMP Collector
|-MO with(AFI 1/SAFI 2) enabled-| Sender sends an MO message
| | to Collector
|-------BMP RM(AFI 1/SAFI 2)--> | Sender sends zero or more
| | Route Monitoring Messages
| | for theIPv4 multicast
| | address family of the
| | specific BGP peer
| | Collector stores the RIB
| | info for IPv4 multicast
| | address family of the
| | specific BGP peer
Figure 9: Sender enabled the monitoring on IPv4 multicast address
family
4. IANA Considerations
TBD
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5. Security Considerations of Inter-domain SPD
The same considerations as in Section 11 of [RFC7854] apply to this
document. Implementations of this protocol SHOULD require that
sessions only be established with authorized and trusted monitoring
devices. It is also believed that this document does not introduce
any additional security considerations.
6. Contributors
The following people made significant contributions to this document:
To be added.
7. Acknowledgements
The authors would like to acknowledge the review and inputs from xxx.
8. References
8.1. Normative References
[RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918,
DOI 10.17487/RFC2918, September 2000,
<https://www.rfc-editor.org/info/rfc2918>.
[RFC7313] Patel, K., Chen, E., and B. Venkatachalapathy, "Enhanced
Route Refresh Capability for BGP-4", RFC 7313,
DOI 10.17487/RFC7313, July 2014,
<https://www.rfc-editor.org/info/rfc7313>.
[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>.
[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>.
8.2. Informative References
[RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering
Capability for BGP-4", RFC 5291, DOI 10.17487/RFC5291,
August 2008, <https://www.rfc-editor.org/info/rfc5291>.
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[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>.
[RFC8671] Evens, T., Bayraktar, S., Lucente, P., Mi, P., and S.
Zhuang, "Support for Adj-RIB-Out in the BGP Monitoring
Protocol (BMP)", RFC 8671, DOI 10.17487/RFC8671, November
2019, <https://www.rfc-editor.org/info/rfc8671>.
[RFC9069] Evens, T., Bayraktar, S., Bhardwaj, M., and P. Lucente,
"Support for Local RIB in the BGP Monitoring Protocol
(BMP)", RFC 9069, DOI 10.17487/RFC9069, February 2022,
<https://www.rfc-editor.org/info/rfc9069>.
Authors' Addresses
Nan Geng
Huawei Technologies
Beijing
China
Email: gengnan@huawei.com
Shunwan Zhuang
Huawei Technologies
Beijing
China
Email: zhuangshunwan@huawei.com
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