Supported

RFC 4760 - Multiprotocol Extensions for BGP-4

Every requirement this repository extracted from RFC 4760, 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 ways66.7%4 of 6 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 reason33.3%2 of 6 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 6 binding obligations

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

No test at all0.0%0 of 6 binding obligations

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

Proven by a recorded break0.0%0 of 22 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 MUSTs6of 17 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 6 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 6 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	17
Gated MUST-level	6
Obligations that bind Ze	6
Not applicable, so out of scope	0
Declared gaps	0
Gated with no test	0
Nightly-only evidence	0
Test tags	22
Tagged units	22
Recorded audit verdicts	0
Discrimination records	0
Summary	`rfc/short/rfc4760.md`
Requirement shard	`rfc/requirements/rfc4760.md`
RFC text	`rfc/full/rfc4760.txt`

Enrolment

Enrolled: Multiprotocol Extensions for BGP-4: six MUST-level requirements. Five are met: 3-2 (the next-hop length determines the next-hop protocol) carries positive+negative tags; 3-3 (an UPDATE with MP_REACH_NLRI also carries ORIGIN and AS_PATH) and 3-4 (an iBGP UPDATE carrying MP_REACH includes LOCAL_PREF) carry positive+negative tags on new internal/component/bgp/message tests; 3-1 (the MP_REACH Reserved octet is 0) and 8-1 (advertise the Multiprotocol capability) are {single-polarity: positive}. 7-1 (Section 7 bulk per-AFI/SAFI route deletion) is {not-applicable}: ze supersedes it with RFC 7606 revised error handling (treat-as-withdraw per NLRI or session reset).

What the public ledger says

Status: Supported

What the ledger says is covered:

AFI/SAFI capability negotiation, MP_REACH_NLRI, MP_UNREACH_NLRI, family-specific UPDATE handling.

What the ledger says remains:

RFC 7606 MP attribute ordering tradeoff is tracked under RFC 7606.

Coverage

Bucket	Count	What it counts
Positive and negative tests	4	one part of the gated population
Annotated instead of tested	2	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	6	every gated MUST falls in exactly one bucket above

Positive and negative tests (4): RFC4760-3-2, RFC4760-3-3, RFC4760-3-4, RFC4760-7-1

Annotated instead of tested (2): RFC4760-3-1, RFC4760-8-1

Requirements

Requirement	Level	Section	Tests
`RFC4760-3-1`	Reserved field in MP_REACH_NLRI MUST be set to 0 (Section 3)
	MUST	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`unit/verifyTestMPReachNLRI_WriteTo` positive`unit/verifyTestRFC4760ReservedIsWrittenNotInherited` positive`unit/verifyTestRFC4760ReservedSurvivesBufferReuse` negative`no test`no negative test {single-polarity}: MPReachNLRI.WriteTo writes the Reserved octet as 0 unconditionally, so there is no non-zero form to reject (internal/core/bgp/attribute/mpnlri.go:182)
`RFC4760-3-2`	If Next Hop is allowed to be from more than one Network Layer protocol, encoding of the Next Hop MUST provide a way to determine its Network Layer protocol (Section 3)
	MUST	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`unit/verifyTestCommitVPNAnnounceCarriesTheRFC4364NextHop` positive`unit/verifyTestMPReachNLRI_WriteTo` positive`unit/verifyTestMPReachNextHopLengthCountsTheOctetsWritten` positive`unit/verifyTestParseMPReachNLRI` negative`unit/verifyTestBuildRIBRouteUpdate_RefusesANextHopWithNoWireForm` negative`unit/verifyTestCommitRefusesAnAnnounceWhoseNextHopHasNoWireForm` negative`unit/verifyTestMPReachValidateNextHopsRefusesAnAddressWithNoWireForm` negative`unit/verifyTestParseMPReachNLRI_InvalidNextHopLength`
`RFC4760-3-3`	An UPDATE message carrying MP_REACH_NLRI MUST also carry the ORIGIN and AS_PATH attributes (Section 3)
	MUST	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`unit/verifyTestRFC4760MPReachRequiresOriginAndASPath` negative`unit/verifyTestRFC4760MPReachRequiresOriginAndASPath`
`RFC4760-3-4`	In IBGP exchanges, an UPDATE with MP_REACH_NLRI MUST also carry the LOCAL_PREF attribute (Section 3)
	MUST	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`unit/verifyTestRFC4760IBGPMPReachCarriesLocalPref` negative`unit/verifyTestRFC4760IBGPMPReachCarriesLocalPref`
`RFC4760-7-1`	On incorrect MP_REACH_NLRI or MP_UNREACH_NLRI, the speaker MUST delete all BGP routes from that neighbor for that AFI/SAFI (Section 7). RFC 7606 does not retire this: Section 3 clause (j) says that when the MP attribute cannot be parsed, "the procedures of [RFC4271] and/or [RFC4760] continue to apply, meaning that the 'session reset' approach (or the 'AFI/SAFI disable' approach) MUST be followed". Ze follows session reset, the stronger of the two, which drops every route from that neighbor and so a superset of that AFI/SAFI's routes. ValidateUpdateRFC7606 (internal/component/bgp/message/rfc7606.go) returns RFC7606ActionSessionReset for an unparseable MP_REACH_NLRI or MP_UNREACH_NLRI, and rfc7606SessionReset (internal/component/bgp/reactor/session_validation.go) sends the NOTIFICATION and closes the connection.
	MUST	7 - Error Handling	positive`unit/verifyTestHandleState_PeerDown` positive`unit/verifyTestRFC4760IncorrectMPAttributeResetsTheSession` positive`unit/verifyTestRFC4760IncorrectMPReachDeletesTheNeighborsRoutes` positive`unit/verifyTestRFC4760IncorrectMPUnreachDeletesTheNeighborsRoutes` negative`unit/verifyTestRFC4760CorrectMPReachKeepsTheNeighborsRoutes` negative`unit/verifyTestRFC4760IncorrectMPAttributeResetsTheSession`
`RFC4760-8-1`	For bi-directional exchange of routing information for a particular AFI/SAFI, each speaker MUST advertise the capability to support that AFI/SAFI via Capability Advertisement (Section 8)
	MUST	8 - Use of BGP Capability Advertisement	positive`unit/verifyTestParseCapabilities` negative`no test`no negative test {single-polarity}: the obligation is to advertise a well-formed Multiprotocol capability per AFI/SAFI, enforced by the fixed 4-octet AFI/Reserved/SAFI wire form (internal/core/bgp/capability/capability.go:299-318); there is no malformed-advertisement counter-case distinct from RFC 5492 TLV framing
`RFC4760-3-5`	Reserved field in MP_REACH_NLRI SHOULD be ignored upon receipt (Section 3)
	SHOULD	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`no test`no positive test negative`no test`no negative test
`RFC4760-3-6`	The next hop in MP_REACH_NLRI SHOULD be used as the next hop to listed destinations (Section 3)
	SHOULD	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`no test`no positive test negative`no test`no negative test
`RFC4760-3-7`	An UPDATE carrying no NLRI other than MP_REACH_NLRI SHOULD NOT carry the NEXT_HOP attribute (Section 3)
	SHOULD NOT	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`no test`no positive test negative`no test`no negative test
`RFC4760-3-8`	If such a message contains NEXT_HOP, the receiver SHOULD ignore this attribute (Section 3)
	SHOULD	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`no test`no positive test negative`no test`no negative test
`RFC4760-3-9`	An UPDATE SHOULD NOT include the same address prefix in more than one of WITHDRAWN ROUTES, NLRI, MP_REACH_NLRI, and MP_UNREACH_NLRI fields (Section 3)
	SHOULD NOT	3 - Multiprotocol Reachable NLRI - MP_REACH_NLRI (Type Code 14)	positive`no test`no positive test negative`no test`no negative test
`RFC4760-7-2`	After deleting routes for an incorrect attribute, speaker SHOULD ignore all subsequent routes with that AFI/SAFI for the session (Section 7)
	SHOULD	7 - Error Handling	positive`no test`no positive test negative`no test`no negative test
`RFC4760-7-3`	Session SHOULD be terminated with UPDATE Message Error / Optional Attribute Error on incorrect attribute (Section 7)
	SHOULD	7 - Error Handling	positive`no test`no positive test negative`no test`no negative test
`RFC4760-8-2`	A BGP speaker using Multiprotocol Extensions SHOULD use Capability Advertisement to determine support with a peer (Section 8)
	SHOULD	8 - Use of BGP Capability Advertisement	positive`no test`no positive test negative`no test`no negative test
`RFC4760-8-3`	Reserved field in Multiprotocol Capability SHOULD be set to 0 by sender and ignored by receiver (Section 8)
	SHOULD	8 - Use of BGP Capability Advertisement	positive`no test`no positive test negative`no test`no negative test
`RFC4760-7-4`	The speaker MAY terminate the BGP session on incorrect MP_REACH_NLRI or MP_UNREACH_NLRI (Section 7)
	MAY	7 - Error Handling	positive`no test`no positive test negative`no test`no negative test
`RFC4760-6-1`	An implementation MAY support all, some, or none of the SAFI values defined in this document (Section 6)
	MAY	6 - Subsequent Address Family Identifier	positive`no test`no positive test negative`no test`no negative test

Gaps and untested MUSTs

RFC 4760 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.