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IETF RFC 9785
[ACTIVE]

Preference-Based EVPN Designated Forwarder (DF) Election

Metadata

Publisher
IETF
Doc Type
Standard
Pages
17
Abstract
The Designated Forwarder (DF) in Ethernet Virtual Private Networks (EVPNs) is defined as the Provider Edge (PE) router responsible for sending Broadcast, Unknown Unicast, and Multicast (BUM) traffic to a multihomed device/network in the case of an All-Active multihoming Ethernet Segment (ES) or BUM and unicast in the case of Single-Active multihoming. The Designated Forwarder is selected out of a candidate list of PEs that advertise the same Ethernet Segment Identifier (ESI) to the EVPN network, according to the default DF election algorithm. While the default algorithm provides an efficient and automated way of selecting the Designated Forwarder across different Ethernet Tags in the Ethernet Segment, there are some use cases where a more "deterministic" and user-controlled method is required. At the same time, Network Operators require an easy way to force an on-demand Designated Forwarder switchover in order to carry out some maintenance tasks on the existing Designated Forwarder or control whether a new active PE can preempt the existing Designated Forwarder PE. This document proposes use of a DF election algorithm that meets the requirements of determinism and operation control. This document updates RFC 8584 by modifying the definition of the DF Election Extended Community.
Publication Date
2025-06-01
Status Note
Proposed Standard
DOI
10.17487/RFC9785
Link
https://doi.org/10.17487/RFC9785
Author(s)
Jorge Rabadan
Senthil Sathappan
Wen Lin
John Drake
Ali Sajassi
Keyword(s)
Non-revertive, Preemption
Latest version of IETF RFC 9785

Document Versions — IETF RFC 9785

  • ▶ IETF RFC 9785 (2025-06-01)
    THIS DOC [ACTIVE] [LATEST VERSION]

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Amends:
IETF RFC 8584 [Active*]

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IETF RFC 9785, Preference-Based EVPN Designated Forwarder (DF) Election. Available at https://doi.org/10.17487/RFC9785
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IETF RFC 9785, Preference-Based EVPN Designated Forwarder (DF) Election. Available at https://doi.org/10.17487/RFC9785

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IETF RFC 9785, Preference-Based EVPN Designated Forwarder (DF) Election. Available at https://doi.org/10.17487/RFC9785
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<span class="citation"><cite>IETF RFC 9785</cite>, Preference-Based EVPN Designated Forwarder (DF) Election. Available at <a href="https://doi.org/10.17487/RFC9785" target="_blank" rel="noopener">https://doi.org/10.17487/RFC9785</a></span>

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IETF RFC 9785, Preference-Based EVPN Designated Forwarder (DF) Election
doi: 10.17487/RFC9785
url: https://doi.org/10.17487/RFC9785
Snippet:
<li>
<cite id="bib-rfc9785">IETF RFC 9785</cite>, Preference-Based EVPN Designated Forwarder (DF) Election
<span class="doi">10.17487/RFC9785</span>
</li>