Supported

RFC 1997 - BGP Communities Attribute

Every requirement this repository extracted from RFC 1997, 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%5 of 5 binding obligations

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 5 binding obligations

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 5 binding obligations

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

No test at all0.0%0 of 5 binding obligations

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

Proven by a recorded break3.8%1 of 26 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 MUSTs5of 9 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 5 gated MUSTs

a {not-applicable} annotation says the obligation does not bind Ze. Scope, not coverage: it is in no share below

The 4 shares marked as a part above are the whole of the 5 obligations that bind Ze: 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
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
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	9
Gated MUST-level	5
Obligations that bind Ze	5
Not applicable, so out of scope	0
Declared gaps	0
Gated with no test	0
Nightly-only evidence	0
Test tags	26
Tagged units	26
Recorded audit verdicts	0
Discrimination records	1
Summary	`rfc/short/rfc1997.md`
Requirement shard	`rfc/requirements/rfc1997.md`
RFC text	`rfc/full/rfc1997.txt`

Enrolment

Enrolled: BGP Communities: five MUST-level requirements. RFC1997-Encoding-1 (attribute length a multiple of 4) is enforced on the wire-decode path by ParseCommunities (internal/core/bgp/attribute/community.go:201, wired via wire.go knownAttrParsers); the positive/negative pair proves a valid multiple-of-4 parses into length/4 communities while a non-multiple-of-4 is rejected as malformed (ErrInvalidLength). The three egress MUST-NOTs (Well-1 NO_EXPORT, Well-2 NO_ADVERTISE, Well-3 NO_EXPORT_SUBCONFED) and the Well-4 SHALL are enforced automatically, with no operator policy involved: wireu.ScanWellKnown reads the RECEIVED payload once per UPDATE and WellKnown.AllowsEgressTo (internal/component/bgp/wireu/wellknown.go) decides per destination, asked by both forward rails through Reactor.wellKnownAllowsEgress (internal/component/bgp/reactor/forward_wellknown.go). The word "received" in each clause is load-bearing and bounds the check: a route Ze ORIGINATES carrying NO_EXPORT is using the community for its purpose and is still advertised (test/interop/scenarios/as112-community-frr). The confederation boundary is the AS boundary because Ze configures no confederation, which is what the NO_EXPORT clause itself directs for "a stand-alone autonomous system that is not part of a confederation". Proof runs at three tiers: unit pairs over the decision and both rails, test/plugin/wellknown-no-export-egress.ci and wellknown-no-advertise-egress.ci over a running daemon's wire in the verify tier, and test/interop/scenarios/bgp-wellknown-noexport-frr with FRR (external, must not learn it) and BIRD (internal, must) as independent observers.

What the public ledger says

Status: Supported

What the ledger says is covered

COMMUNITY attribute parsing (multiple-of-4 length enforced), encoding, JSON, well-known names, operator community-match policy, and the well-known egress operations. A route received carrying NO_EXPORT or NO_EXPORT_SUBCONFED is withheld from every external peer, and one carrying NO_ADVERTISE from every peer. The suppression is automatic and needs no operator policy
it is counted by ze_bgp_wellknown_community_suppressed_total. Ze configures no confederation, so the confederation boundary is the AS boundary, which is what RFC 1997 says to do for "a stand-alone autonomous system that is not part of a confederation".

What the ledger says remains:

Gated per requirement in rfc/short/rfc1997.md via ./le rfc check.

Coverage

Bucket	Count	What it counts
Positive and negative tests	5	one part of the gated population
Annotated instead of tested	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
Evidence that runs nightly only	0	an overlay: each of these is also counted by the part it falls in
Gated MUST-level requirements	5	every gated MUST falls in exactly one bucket above

Positive and negative tests (5): RFC1997-Well-1, RFC1997-Well-2, RFC1997-Well-3, RFC1997-Encoding-1, RFC1997-Well-4

Requirements

Requirement	Level	Section	Tests
`RFC1997-Well-1`	Routes with NO_EXPORT community MUST NOT be advertised outside a BGP confederation boundary (§Well-known Communities)
	MUST NOT	Well	positive`unit/verifyTestForwardNoExportSkipsExternalPeerOnly` positive`unit/verifyTestWellKnownNoExportRefusesExternalPeer` negative`unit/verifyTestForwardNoExportStillWithdrawsFromExternalPeer` negative`unit/verifyTestForwardWithoutNoExportReachesExternalPeer` negative`unit/verifyTestWellKnownNoExportAllowsInternalPeer` positive`functional/verifywellknown-no-export-egress.ci` negative`functional/verifywellknown-no-export-egress.ci` negative`functional/verifywellknown-no-export-withdraw-egress.ci` positive`interop/nightlycheckNoExportBoundary` negative`interop/nightlycheckNoExportBoundary`
`RFC1997-Well-2`	Routes with NO_ADVERTISE community MUST NOT be advertised to other BGP peers (§Well-known Communities)
	MUST NOT	Well	positive`unit/verifyTestForwardNoAdvertiseSkipsEveryPeer` positive`unit/verifyTestWellKnownNoAdvertiseRefusesEveryPeer` negative`unit/verifyTestWellKnownNoAdvertiseAbsentAdvertisesToEveryPeer` positive`functional/verifywellknown-no-advertise-egress.ci` negative`functional/verifywellknown-no-advertise-egress.ci`
`RFC1997-Well-3`	Routes with NO_EXPORT_SUBCONFED community MUST NOT be advertised to external BGP peers, including peers in other member ASes inside a confederation (§Well-known Communities)
	MUST NOT	Well	positive`unit/verifyTestForwardNoExportSubconfedSkipsExternalPeerOnly` positive`unit/verifyTestWellKnownNoExportSubconfedRefusesExternalPeer` negative`unit/verifyTestWellKnownNoExportSubconfedAllowsInternalPeer` positive`functional/verifywellknown-no-advertise-egress.ci` negative`functional/verifywellknown-no-advertise-egress.ci`
`RFC1997-Encoding-1`	Attribute length MUST be a multiple of 4 (§Encoding Rules)
	MUST	Encoding	positive`unit/verifyTestCommunitiesParse` negative`unit/verifyTestCommunitiesParseRejectsNonMultipleOf4`
`RFC1997-Well-4`	Well-known community operations SHALL be implemented in any community-attribute-aware BGP speaker (§Well-known Communities)
	SHALL	Well	positive`unit/verifyTestForwardWellKnownNeedsNoOperatorPolicy` positive`unit/verifyTestWellKnownAllThreeOperationsImplemented` negative`unit/verifyTestForwardOtherReservedCommunitiesReachExternalPeer` negative`unit/verifyTestWellKnownIgnoresOtherReservedCommunities`
`RFC1997-Aggregation-1`	When aggregating routes without ATOMIC_AGGREGATE, the resulting aggregate SHOULD have a COMMUNITIES attribute containing all communities from all aggregated routes (§Aggregation)
	SHOULD	Aggregation	positive`no test`no positive test negative`no test`no negative test
`RFC1997-Operation-1`	A BGP speaker MAY use the COMMUNITIES attribute to control which routing information it accepts, prefers, or distributes (§Operation)
	MAY	Operation	positive`no test`no positive test negative`no test`no negative test
`RFC1997-Operation-2`	A BGP speaker receiving a route without COMMUNITIES MAY append this attribute when propagating to peers (§Operation)
	MAY	Operation	positive`no test`no positive test negative`no test`no negative test
`RFC1997-Operation-3`	A BGP speaker receiving a route with COMMUNITIES MAY modify the attribute according to local policy (§Operation)
	MAY	Operation	positive`no test`no positive test negative`no test`no negative test

Gaps and untested MUSTs

RFC 1997 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.

`RFC1997-Well-1`

Routes with NO_EXPORT community MUST NOT be advertised outside a BGP confederation boundary (§Well-known Communities)