Supported

RFC 9774 - Deprecation of AS_SET and AS_CONFED_SET in BGP

Every requirement this repository extracted from RFC 9774, the tests bound to it, and what a reader has verified about them. This summary is enrolled and gated by ./le rfc check.

Overview

Positive

what Ze has

Tested both ways100.0%2 of 2 gated MUSTs

a positive test proves Ze does what the requirement demands and a negative one proves it refuses what the requirement forbids

One polarity plus reason0.0%0 of 2 gated MUSTs

the requirement admits no counter-case, so one polarity plus a recorded reason is the whole proof available for it

One polarity, unexcused0.0%0 of 2 gated MUSTs

one direction is tested, the other is neither tested nor excused, and nothing states which

Partial proof; remaining gap0.0%0 of 2 gated MUSTs

scoped tests exist; the remaining obligation is unmet or unproven, with zero whole-requirement credit

No test at all0.0%0 of 2 gated MUSTs

no test carries the requirement id, whether or not a gap states why

Proven by a recorded break100.0%10 of 10 tagged units

a red was observed once under a recorded procedure, and the unit, the claim and the producer it rested on still hash to what was recorded. The break is not re-run. A test pair is not a proof until one has been observed

Neutral

measures that are neither good news nor bad

Gated MUSTs2of 2 this summary declares

MUST-level requirements the gate HOLDS. A population, not a result: the shares beside it are what says how Ze stands

Out of scope0of 2 gated MUSTs

an obligation that does not bind Ze. A {not-applicable} annotation says it never bound; a {feature-declined} annotation says its condition is an optional feature Ze does not offer, and quotes the RFC sentence that makes it optional. Scope, not coverage: it stays in the denominator every share on this page is taken over

Not applicable0.0%0 of 2 gated MUSTs

a {not-applicable} annotation says the obligation does not bind Ze, so no test is owed for it. It stays in the denominator every share here is taken over

Met below Ze0.0%0 of 2 gated MUSTs

a {lower-layer} annotation says a layer under Ze performs the behavior, on state Ze installs into that layer, and names the producer that installs it. The obligation binds Ze and is met; Ze proves none of it, because its own boundary carries no value the behavior reads

Optional feature declined0.0%0 of 2 gated MUSTs

a {feature-declined} annotation says the obligation is conditional on a feature the RFC makes optional and Ze does not offer, and it quotes the sentence that makes it optional. The condition is false, so nothing is owed and nothing is missing. It stays in the denominator every share here is taken over

The 8 shares marked as a part above are the whole of the 2 gated MUSTs: they add to 100%. Proven by a recorded break is a share of TAGGED UNITS, a different population, so it is not one of them.

How to read the colors

A color names what the measure MEANS, not how well Ze scores on it. Green is a good outcome at any value, red is a bad one, and neither a population nor a scope count is an outcome, so both take no color. The number under the label is what says how far Ze has got.

Card	Tone here	Why that color
Gated MUSTs	neutral	no color: a population is a scale, and a larger one is neither good news nor bad. It is the accounting total
Out of scope	neutral	no color: an obligation that never bound Ze is neither an achievement nor a failure, and counting it either way would be a claim
Tested both ways	ok	green at every value: a test pair is the outcome this gate exists to produce, and the share under the label is what says how far Ze has got
One polarity plus reason	ok	green at every value: where no counter-case exists, one polarity IS the complete answer, and a recorded reason is what the gate demands beside it
One polarity, unexcused	ok	green at zero, RED above it: half a proof with no reason for the other half
Partial proof; remaining gap	ok	green at zero, RED above it: a tested clause cannot prove the whole requirement
No test at all	ok	green at zero, RED above it: a binding obligation nothing exercises is a claim with nothing behind it, whether or not a reason is stated
Not applicable	neutral	no color: an obligation that never bound Ze is neither an achievement nor a failure, and counting it either way would be a claim
Met below Ze	neutral	no color: an obligation met below Ze is neither a test Ze wrote nor work Ze owes, and the two green shares above are what says how much Ze proves itself
Optional feature declined	neutral	no color: an obligation whose condition Ze never meets is neither an achievement nor a failure. The absent FEATURE is disclosed on the RFC's own status row, as an implementation gap a later scope decision can revisit
Proven by a recorded break	ok	green at every value: an observed break is the outcome the discrimination gate exists to produce. The denominator is TAGGED UNITS, not obligations, so this share is not one of the parts above
Audit verdicts	warn	RED on the first weak, wrong or unimplemented verdict, amber while a verdict is no longer current or a gated MUST is unjudged, green when every one is judged sound and current

At a glance

Field	Value
Public status	Supported
Enrolment	Enrolled
Requirements	2
Gated MUST-level	2
Not applicable, so out of scope	0
Declared gaps	0
Declared gaps a test demonstrates	0
Gated with no test	0
Nightly-only evidence	0
Test tags	10
Tagged units	10
Recorded audit verdicts	1
Discrimination records	10
Summary	`rfc/short/rfc9774.md`
Requirement shard	`rfc/requirements/rfc9774.md`
RFC text	`rfc/full/rfc9774.txt`

Enrolment

Enrolled: Owner decision 2026-10-18, "Implement RFC 9774", lifting the 2026-10-08 enrolment freeze for this RFC only. Two MUST-level requirements, both in Section 3, both met and proven in both polarities. RFC9774-3-2 (treat-as-withdraw on receipt of an AS_SET or AS_CONFED_SET in AS_PATH or AS4_PATH) is enforced by validateASPathAttr (internal/component/bgp/message/rfc7606.go) and validateAS4PathAttr (internal/component/bgp/message/rfc7607.go), which share ASPathSetSegment (internal/component/bgp/message/rfc9774.go). RFC9774-3-1 (never advertise an UPDATE containing either set) is enforced by Session.transmittedPathHoldsSet and Session.writeUpdateAsWithdrawal (internal/component/bgp/reactor/session_rfc9774.go), called from Session.writeUpdateBody, the one UPDATE writer. The two MUST-level sites of Sections 5.2 and 6.1 bind route aggregation, which Ze does not implement, and are excluded as feature-out-of-scope in rfc/extraction/rfc9774.json. Enrolled 2026-10-19.

What the public ledger says

Status: Supported

What the ledger says is covered

internal/component/bgp/message/rfc9774.go (ASPathSetSegment), internal/component/bgp/message/rfc7606.go (validateASPathAttr), internal/component/bgp/message/rfc7607.go (validateAS4PathAttr), internal/component/bgp/reactor/session_rfc9774.go (transmittedPathHoldsSet, writeUpdateAsWithdrawal), internal/component/bgp/reactor/session_write.go (writeUpdateBody)

What the ledger says remains

Both Section 3 MUST-level requirements implemented, each with a positive and a negative test tag.

One operator override, on receive only: the peer leaf session as-set accept, set by the operator (and written by ze exabgp migrate for an ExaBGP as-set accept neighbor), keeps a received set (see "Owner-approved deviation"; not counted as conformant). The send bgp <peer> raw test instrument writes operator bytes as given. Route aggregation (Sections 5, 5.2, 6.1, 6.2) is not implemented, so its obligations are an implementation gap outside the conformance count.

Coverage

Bucket	Count	What it counts
Positive and negative tests	2	one part of the gated population
Annotated (including scoped evidence)	0	one part of the gated population
One polarity only	0	one part of the gated population
No test and no annotation	0	one part of the gated population
Partial proof; remaining gap (subset of annotated; zero whole-requirement credit)	0	an overlay: each of these is also counted by the part it falls in
Evidence that runs nightly only	0	an overlay: each of these is also counted by the part it falls in
Derived from other rows	0	outside the gated population: each asserts nothing and derives its state from the rows it names, which the parts above already count
Gated MUST-level requirements	2	every gated MUST falls in exactly one bucket above

Positive and negative tests (2): RFC9774-3-1, RFC9774-3-2

Requirements

Requirement	Level	Section	Tests
`RFC9774-3-1`	MUST NOT advertise BGP UPDATE messages containing AS_SETs or AS_CONFED_SETs (§3)
	MUST NOT	3	positive`unit/verifyTestRFC9774SendASSetWrittenAsWithdrawal` negative`unit/verifyTestRFC9774SendASSetWrittenAsWithdrawal`
`RFC9774-3-2`	MUST use the "treat-as-withdraw" error handling behavior per [RFC7606] upon reception of BGP UPDATE messages containing AS_SETs or AS_CONFED_SETs in the AS_PATH or AS4_PATH [RFC6793] (§3)
	MUST	3	positive`unit/verifyTestRFC9774ReceiveAS4PathSetTreatAsWithdraw` positive`unit/verifyTestRFC9774ReceiveASSetAcceptedByOperator` positive`unit/verifyTestRFC9774ReceiveASSetTreatAsWithdraw` positive`unit/verifyTestValidateAS4PathRejectsSetSegments` positive`unit/verifyTestValidateASPathRejectsSetSegments` negative`unit/verifyTestRFC9774ReceiveAS4PathSetTreatAsWithdraw` negative`unit/verifyTestRFC9774ReceiveASSetTreatAsWithdraw` negative`unit/verifyTestValidateASPathRejectsSetSegments`

Gaps and untested MUSTs

RFC 9774 declares no gap, and every gated MUST it carries has a test bound to it.

Proof state

A tagged unit reads unproven where no discrimination record exists for it: nothing in this tree has been observed to break it, so the claim its tag makes is unproven.

`RFC9774-3-1`

MUST NOT advertise BGP UPDATE messages containing AS_SETs or AS_CONFED_SETs (§3)

Audit verdict: not audited: no reader has judged these tests

Polarity	Test	Kind and tier	Proof state
negative	`TestRFC9774SendASSetWrittenAsWithdrawal`	unit/verify	revert, verified
positive	`TestRFC9774SendASSetWrittenAsWithdrawal`	unit/verify	revert, verified

`RFC9774-3-2`

MUST use the "treat-as-withdraw" error handling behavior per [RFC7606] upon reception of BGP UPDATE messages containing AS_SETs or AS_CONFED_SETs in the AS_PATH or AS4_PATH [RFC6793] (§3)

Audit verdict: enforced (the tests do what the requirement demands), fresh. Re-judged 2026-10-24 (independent auditor, authored none of 9c3697d0d1 or 439a413ffd). RFC 9774 Section 3: "Unless explicitly configured by a network operator to do otherwise (e.g., during a transition phase), BGP speakers:" ... "MUST use the "treat-as-withdraw" error handling behavior per [RFC7606] upon reception of BGP UPDATE messages containing AS_SETs or AS_CONFED_SETs in the AS_PATH or AS4_PATH [RFC6793]." The weak judgement of 926410a332 (AS4_PATH clause proven at positive polarity only, AS_SET only, 2-octet session only) is answered by new tags, not new code: TestRFC9774ReceiveAS4PathSetTreatAsWithdraw now carries positive and negative. Re-read its body: an UPDATE with a sequence-only AS_PATH and an AS4_PATH holding AS_SET or AS_CONFED_SET draws exact TreatAsWithdraw from Session.enforceRFC7606 with no error on a 2-octet session (rfc7607Session) and on a 4-octet eBGP session (firstASSession with ASN4), and the twin with a sequence segment in the set's place draws exact None on both, so the verdict is bound to the segment type alone and an over-withdraw of a clean AS4_PATH goes red. TestValidateAS4PathRejectsSetSegments (new positive) asserts for asn4 false and true exact TreatAsWithdraw, AttrCode 17 and the exact RFC 9774 Section 3 description for AS_SET, AS_CONFED_SET and a set beside AS 0, and its controls assert discard for AS 0 alone, nil for a clean path and nil from the set scan for a misframed path. The AS_PATH clause stays enforced by TestValidateASPathRejectsSetSegments and TestRFC9774ReceiveASSetTreatAsWithdraw (unchanged); TestRFC9774ReceiveASSetAcceptedByOperator proves the default through parsePeerFromTree and its false comment (AS4_PATH reaches its validator only on a 2-octet session) is corrected. Both earlier findings closed. Each claim states what its body checks. Discrimination records observed red: positive on both AS4_PATH units under rfc7607.go !acceptASSet forced false, negative under the rfc9774.go segment-type comparison inverted. The operator exception is an uncounted deviation recorded in rfc/short/rfc9774.md. Units ran green at HEAD.

Polarity	Test	Kind and tier	Proof state
negative	`TestValidateASPathRejectsSetSegments`	unit/verify	revert, verified
negative	`TestRFC9774ReceiveAS4PathSetTreatAsWithdraw`	unit/verify	mutant, verified
negative	`TestRFC9774ReceiveASSetTreatAsWithdraw`	unit/verify	revert, verified
positive	`TestValidateAS4PathRejectsSetSegments`	unit/verify	mutant, verified
positive	`TestValidateASPathRejectsSetSegments`	unit/verify	revert, verified
positive	`TestRFC9774ReceiveASSetAcceptedByOperator`	unit/verify	revert, verified
positive	`TestRFC9774ReceiveAS4PathSetTreatAsWithdraw`	unit/verify	mutant, verified
positive	`TestRFC9774ReceiveASSetTreatAsWithdraw`	unit/verify	revert, verified

Extraction sign-off

Field	Value
Reviewer	ze-implement agent, spec-bgp-rfc9774-as-set-deprecation
Signed off	2026-10-19
Register	rfc2119
Source	rfc/full/rfc9774.txt
Source fingerprint	1c7ab2a8ddf3a013
Record	rfc/extraction/rfc9774.json
Mapped sentences	2
Declined as scope	2
Relocated to a spec, which Ze OWES	0
Unclassified	0

Sections

Section	Name	Sites	Disposition	Reason
`front`	not stated	0	skipped (front-matter)	Title block, Status of This Memo, copyright notice, Abstract and Table of Contents. The Abstract states scope and binds nobody.
`1`	Introduction	0	walked	Introduction. Explains why AS_SET and AS_CONFED_SET complicate BGP security and states the document updates RFC 4271 and RFC 5065 and obsoletes RFC 6472. No RFC 2119 keyword; the obligations are stated in section 3.
`2`	Requirements Language boilerplate citing BCP 14	0	walked	Requirements Language boilerplate citing BCP 14. It defines keywords and obliges nobody.
`3`	not stated	2	walked	The two obligations of the document, both mapped: 3:1 to RFC9774-3-1 (send) and 3:2 to RFC9774-3-2 (receive). The closing paragraph records which sections of RFC 4271 and RFC 5065 are updated and binds nothing further.
`4`	not stated	0	walked	Describes how RPKI-ROV, BGPsec and ASPA already treat a route with an AS_SET. Descriptive, no RFC 2119 keyword, and it obliges no BGP speaker beyond the documents it cites.
`5`	Describes brief aggregation	0	walked	Describes brief aggregation. Its one SHOULD is a quotation of RFC 4271 Section 5.1.6 and belongs to RFC 4271; the section adds no obligation of its own.
`5.1`	not stated	0	walked	Explains why brief aggregation yields an unpredictable origin AS for RPKI-ROV. Descriptive, no RFC 2119 keyword.
`5.2`	Consistent brief aggregation	1	walked	Consistent brief aggregation. Its MUST (5.2:1) and its SHOULD to attach ATOMIC_AGGREGATE bind an aggregating implementation; Ze implements no aggregation, so 5.2:1 is excluded as feature-out-of-scope.
`6`	not stated	0	walked	Section preamble: operator advice on deployment and configuration. No keyword.
`6.1`	not stated	1	walked	Its MUST (6.1:1) binds an operator that aggregates; excluded as feature-out-of-scope with 5.2:1.
`6.2`	not stated	0	walked	SHOULD NOT and SHOULD on announcing an aggregate to contributing ASes; recommendations conditional on aggregation, which Ze does not implement. No MUST-level site.
`6.3`	not stated	0	walked	Reminds that RFC 4632 Section 5.1 Rule 2 binds aggregating implementations; it restates another document and adds no keyword.
`7`	Security Considerations	0	walked	Security Considerations. Notes the deprecation shrinks the attack surface. No keyword.
`8`	not stated	0	skipped (iana)	IANA Considerations: marks segment types 1 and 4 deprecated in the registry. A registry action, no speaker obligation.
`9`	References heading	0	skipped (references)	References heading.
`9.1`	Normative references	0	skipped (references)	Normative references.
`9.2`	Informative references	0	skipped (references)	Informative references.
`A`	not stated	0	skipped (appendix-non-normative)	Example filtering policy for not advertising an aggregate to contributing ASes. Illustrative, no keyword.
`B`	not stated	0	skipped (appendix-non-normative)	Examples of consistent brief aggregation and the ROAs they need. Illustrative, no keyword.
`B.1`	Worked example of Appendix B	0	skipped (appendix-non-normative)	Worked example of Appendix B. Illustrative.
`B.2`	Worked example of Appendix B	0	skipped (appendix-non-normative)	Worked example of Appendix B. Illustrative.
`B.3`	Worked example of Appendix B	0	skipped (appendix-non-normative)	Worked example of Appendix B. Illustrative.
`B.4`	Worked example of Appendix B	0	skipped (appendix-non-normative)	Worked example of Appendix B. Illustrative.
`C`	Discussion of forwarding loops and AS_SETs	0	skipped (appendix-non-normative)	Discussion of forwarding loops and AS_SETs. Explanatory, no keyword.

Excluded sentences

Site	Excluded kind	Reason	Quote
`5.2:1`	`feature-out-of-scope` never bound Ze the RFC makes a feature OPTIONAL, Ze decided not to offer it, and this obligation is conditional on offering it	Binds implementations of brief BGP aggregation only. RFC 4271 Section 9.1 makes route aggregation optional: "Route aggregation and information reduction can optionally be performed within this phase." Owner decision 2026-10-18 scoped this work to RFC 9774 and not to an aggregation feature (spec-bgp-rfc9774-as-set-deprecation, Key Design Decisions). Ze has no aggregation code: the AS_PATH parsers (ParseASPathText, internal/core/bgp/attribute/text.go) build only AS_SEQUENCE.	To ensure a consistent BGP origin AS is announced for aggregate BGP routes for implementations of "brief" BGP aggregation, the implementation MUST be configured to truncate the AS_PATH after the right-most instance of the desired origin AS for the aggregate.
`6.1:1`	`feature-out-of-scope` never bound Ze the RFC makes a feature OPTIONAL, Ze decided not to offer it, and this obligation is conditional on offering it	Binds an operator "When aggregating prefixes", which needs an aggregation feature in the speaker. RFC 4271 Section 9.1 makes route aggregation optional: "Route aggregation and information reduction can optionally be performed within this phase." Owner decision 2026-10-18 scoped this work to RFC 9774 and not to an aggregation feature (spec-bgp-rfc9774-as-set-deprecation, Key Design Decisions). Ze has no aggregation code: the AS_PATH parsers (ParseASPathText, internal/core/bgp/attribute/text.go) build only AS_SEQUENCE.	When aggregating prefixes, network operators MUST use consistent brief aggregation as described in Section 5.2.

Superseded

No document obsoletes RFC 9774, so its obligations are stated where they were written.