Supported

RFC 7705 - Autonomous System Migration Mechanisms and Their Effects on the BGP AS_PATH Attribute

Every requirement this repository extracted from RFC 7705, 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%9 of 9 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 9 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 9 gated MUSTs

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

No test at all0.0%0 of 9 gated MUSTs

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

Proven by a recorded break100.0%18 of 18 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 MUSTs9of 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 9 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 9 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 9 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 9 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 7 shares marked as a part above are the whole of the 9 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
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	17
Gated MUST-level	9
Not applicable, so out of scope	0
Declared gaps	0
Gated with no test	0
Nightly-only evidence	0
Test tags	18
Tagged units	18
Recorded audit verdicts	0
Discrimination records	18
Summary	`rfc/short/rfc7705.md`
Requirement shard	`rfc/requirements/rfc7705.md`
RFC text	`rfc/full/rfc7705.txt`

Enrolment

Enrolled: Autonomous System migration: the four de facto mechanisms a renumbering speaker runs, all four implemented, and all nine of this document's MUST-level requirements proven by a tagged test in both polarities. Section 3.3 "Local AS", "No Prepend Inbound" and "Replace Old AS" reach the AS_PATH through `secondaryPrependAS` and `localASPrependFor` (internal/component/bgp/reactor/peer_forward_facts.go). Section 4.2 "Internal BGP AS Migration" is `setMigrationAS`, `isIBGPWith`, `peerASAccepted`, `openLocalAS` and `noteASMigrationRejection` (internal/component/bgp/reactor/session_as_migration.go). The extraction sign-off is rfc/extraction/rfc7705.json: eight derived sites, all mapped, none excluded.

What the public ledger says

Status: Supported

What the ledger says is covered

All four mechanisms. Configuration is one session > asn container read by parsePeerSettings (internal/component/bgp/reactor/config.go) out of the peer-fields grouping that a group and a peer both use, so local, local-options and migration are each settable per neighbor and per neighbor group (RFC7705-3.3-1, RFC7705-4.2-1). Section 3.3: local-options no-prepend keeps the Local AS value out of the AS_PATH of a route received from that peer, and leaves the globally configured AS number on the path every other external neighbor receives (RFC7705-3.3-2, RFC7705-3.3-3)
local-options replace-as sends the Local AS value alone toward that peer, with the globally configured AS number absent from AS_PATH and from AS4_PATH (RFC7705-3.3-4, RFC7705-3.3-5). Section 4.2: session > asn > migration widens one iBGP session to exactly two of this speaker's AS numbers. An OPEN carrying either is accepted and any third AS is answered with OPEN Message Error / Bad Peer AS, which ze originates for the first time (validateOpenPeerAS, internal/component/bgp/reactor/session_open_as.go, RFC7705-4.2-2). The OPEN ze sends carries the globally configured AS number first and the locally configured one after a peer answers Bad Peer AS, in My Autonomous System and in the Four-octet AS capability alike (openLocalAS, RFC7705-4.2-3, and the Section 4.2 SHOULD RFC7705-4.2-5 through noteASMigrationRejection). The session is internal under either AS number, from one rule every AS-scoped decision reads (isIBGPWith, RFC7705-4.2-4), so no external AS_PATH prepend runs and the RFC 4456 reflection rules apply. Requirements bound per line below.

What the ledger says remains

Two advisory items, neither of them a MUST. RFC7705-3.3-9, the Section 3.3 SHOULD that the Local AS value be appended inbound before a route is installed or advertised to an internal neighbor, is not performed by the engine: an operator writes it as policy, and plan/spec-bgp-local-as-inbound-append.md holds the ruling. RFC7705-3.3-11, the MAY letting an EXTERNAL speaker attempt the session under either AS number, is not offered: the two-AS session is iBGP only, because setMigrationAS refuses a remote AS that is neither of the pair. RFC7705-3.3-8, the SHOULD NOT that follows from that MAY, is therefore met by the scope decision rather than by a branch: no external session of ze establishes on the globally configured AS number while a Local AS is set for it.

Coverage

Bucket	Count	What it counts
Positive and negative tests	9	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	9	every gated MUST falls in exactly one bucket above

Positive and negative tests (9): RFC7705-3.3-1, RFC7705-3.3-2, RFC7705-3.3-3, RFC7705-3.3-4, RFC7705-3.3-5, RFC7705-4.2-1, RFC7705-4.2-2, RFC7705-4.2-3, RFC7705-4.2-4

Requirements

Requirement	Level	Section	Tests
`RFC7705-3.3-1`	"The mechanisms introduced in this section MUST be configurable on a per-neighbor or per-neighbor-group basis to allow for maximum flexibility." (§3.3)
	MUST	3.3	positive`unit/verifyTestPeersFromConfigTree_LocalASOptionsPerNeighborGroup` negative`unit/verifyTestPeersFromConfigTree_LocalASOptionsPerNeighborGroup`
`RFC7705-3.3-2`	With "No Prepend Inbound", on inbound UPDATEs from the configured eBGP neighbour the router "MUST NOT append the 'Local AS' ASN value in the AS_PATH attribute when installing the route or advertising that UPDATE to iBGP neighbors" (§3.3)
	MUST NOT	3.3	positive`unit/verifyTestLocalASNoPrependLeavesEveryOutboundPathAlone` negative`unit/verifyTestLocalASNoPrependLeavesEveryOutboundPathAlone`
`RFC7705-3.3-3`	With "No Prepend Inbound", the router "MUST still append the globally configured ASN as normal when advertising the UPDATE to other local eBGP neighbors" (§3.3)
	MUST	3.3	positive`unit/verifyTestLocalASNoPrependLeavesEveryOutboundPathAlone` negative`unit/verifyTestLocalASNoPrependLeavesEveryOutboundPathAlone`
`RFC7705-3.3-4`	With "Replace Old AS", on outbound UPDATEs toward the configured eBGP neighbour "the BGP speaker MUST NOT append the globally configured ASN from the AS_PATH attribute" (§3.3)
	MUST NOT	3.3	positive`unit/verifyTestLocalASReplaceASSendsOnlyTheLocalAS` negative`unit/verifyTestLocalASReplaceASSendsOnlyTheLocalAS`
`RFC7705-3.3-5`	With "Replace Old AS", "The BGP router MUST append only the configured 'Local AS' ASN value to the AS_PATH attribute before sending the BGP UPDATEs outbound to the eBGP neighbor." (§3.3)
	MUST	3.3	positive`unit/verifyTestLocalASReplaceASSendsOnlyTheLocalAS` negative`unit/verifyTestLocalASReplaceASSendsOnlyTheLocalAS`
`RFC7705-4.2-1`	"The mechanism introduced in this section MUST be configurable on a per-neighbor or per-neighbor-group basis to allow for maximum flexibility." (§4.2)
	MUST	4.2	positive`unit/verifyTestPeersFromConfigTree_ASMigrationPerNeighborGroup` negative`unit/verifyTestPeersFromConfigTree_ASMigrationPerNeighborGroup`
`RFC7705-4.2-2`	A speaker configured with "Internal BGP AS Migration" "MUST accept BGP OPEN and establish an iBGP session from configured iBGP peers if the ASN value in 'My Autonomous System' is either the globally configured ASN or a locally configured ASN" (§4.2)
	MUST	4.2	positive`unit/verifyTestMigrationAcceptsEitherASN` negative`unit/verifyTestMigrationAcceptsEitherASN`
`RFC7705-4.2-3`	A router configured with "Internal BGP AS Migration" "MUST send its own BGP OPEN ... using either the globally configured or the locally configured ASN in 'My Autonomous System'" (§4.2)
	MUST	4.2	positive`unit/verifyTestMigrationOpenCarriesResolvedASN` negative`unit/verifyTestMigrationOpenCarriesResolvedASN`
`RFC7705-4.2-4`	"In each case, the BGP speaker MUST treat UPDATEs sent and received to this peer as if this was a natively configured iBGP session, as defined by [RFC4271] and [RFC4456]." (§4.2)
	MUST	4.2	positive`unit/verifyTestMigrationSessionIsIBGP` negative`unit/verifyTestMigrationSessionIsIBGP`
`RFC7705-3.3-6`	To implement "Local AS", "a BGP speaker SHOULD send BGP OPEN ... messages to the configured eBGP peer(s) using the local ASN configured for this session as the value sent in 'My Autonomous System'" (§3.3)
	SHOULD	3.3	positive`no test`no positive test negative`no test`no negative test
`RFC7705-3.3-7`	"The BGP router SHOULD NOT use the ASN configured globally within the BGP process as the value sent in 'My Autonomous System' in the OPEN message." (§3.3)
	SHOULD NOT	3.3	positive`no test`no positive test negative`no test`no negative test
`RFC7705-3.3-8`	"If the session is successfully established to the globally configured ASN, then the modifications to AS_PATH described in this document SHOULD NOT be performed, as they are unnecessary." (§3.3)
	SHOULD NOT	3.3	positive`no test`no positive test negative`no test`no negative test
`RFC7705-3.3-9`	Internal direction: "The router SHOULD append the configured 'Local AS' ASN in the AS_PATH attribute before installing the route or advertising the UPDATE to an iBGP neighbor." (§3.3)
	SHOULD	3.3	positive`no test`no positive test negative`no test`no negative test
`RFC7705-3.3-10`	External direction: "The BGP router SHOULD first append the globally configured ASN to the AS_PATH immediately followed by the 'Local AS' value before advertising the UPDATE to an eBGP neighbor." (§3.3)
	SHOULD	3.3	positive`no test`no positive test negative`no test`no negative test
`RFC7705-4.2-5`	To avoid deadlock when both speakers run the mechanism, "the speaker SHOULD send BGP OPEN using the globally configured ASN first, and only send a BGP OPEN using the locally configured ASN as a fallback if the remote neighbor responds with the BGP error 'Bad Peer AS'" (§4.2)
	SHOULD	4.2	positive`no test`no positive test negative`no test`no negative test
`RFC7705-6-1`	"BGP sessions SHOULD be protected using TCP Authentication Option [RFC5925] and the Generalized TTL Security Mechanism [RFC5082]" (§6)
	SHOULD	6	positive`no test`no positive test negative`no test`no negative test
`RFC7705-3.3-11`	"Implementations MAY support a more flexible model where the eBGP speaker attempts to open the BGP session using either the ASN configured as 'Local AS' or the globally configured AS as discussed in BGP Alias" (§3.3)
	MAY	3.3	positive`no test`no positive test negative`no test`no negative test

Gaps and untested MUSTs

RFC 7705 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.

`RFC7705-3.3-1`

"The mechanisms introduced in this section MUST be configurable on a per-neighbor or per-neighbor-group basis to allow for maximum flexibility." (§3.3)