a positive test proves Ze does what the requirement demands and a negative one proves it refuses what the requirement forbids
Supported
RFC 8203 - BGP Administrative Shutdown Communication
Every requirement this repository extracted from RFC 8203, 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
the requirement admits no counter-case, so one polarity plus a recorded reason is the whole proof available for it
one direction is tested, the other is neither tested nor excused, and nothing states which
scoped tests exist; the remaining obligation is unmet or unproven, with zero whole-requirement credit
no test carries the requirement id, whether or not a gap states why
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
0 weak, wrong or unimplemented, 0 no longer current. Each is named below under its own requirement id
Neutral
measures that are neither good news nor bad
MUST-level requirements the gate HOLDS. A population, not a result: the shares beside it are what says how Ze stands
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
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
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
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 5 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 | ok | 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 |
| 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 | 15 |
| Tagged units | 15 |
| Recorded audit verdicts | 5 |
| Discrimination records | 6 |
| Summary | rfc/short/rfc8203.md |
| Requirement shard | rfc/requirements/rfc8203.md |
| RFC text | rfc/full/rfc8203.txt |
Enrolment
Enrolled: Administrative Shutdown Communication: five MUST-level requirements over the Cease NOTIFICATION shutdown message, all bound to the message codec (internal/component/bgp/message/notification.go). RFC8203-2-1 (subcode 2/4) is proven by ShutdownMessage extracting for Admin Shutdown/Reset and returning empty for any other subcode; RFC8203-2-3 (UTF-8) and RFC8203-2-4 (MUST NOT interpret invalid UTF-8) by a valid message round-tripping while an invalid sequence is rejected; RFC8203-6-1 (shortest form) by an overlong 0xC0 0xAF encoding being rejected where the canonical form is accepted (Go utf8.Valid enforces shortest form). RFC8203-2-2 (length 0-128) is {single-polarity: positive}: BuildShutdownData caps the sender at 128, while the receiver deliberately follows RFC 9003 (which obsoletes RFC 8203 and raised the cap to 255), so there is no over-128 rejection on receive to assert.
What the public ledger says
Status: Supported
What the ledger says is covered:
UTF-8 shutdown message for Cease/Admin Shutdown and Cease/Admin Reset.What the ledger says remains:
Sender keeps the conservative 128-byte RFC 8203 limit.Coverage
| Bucket | Count | What it counts |
|---|---|---|
| Positive and negative tests | 4 | one part of the gated population |
| Annotated (including scoped evidence) | 1 | 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 | 5 | every gated MUST falls in exactly one bucket above |
Positive and negative tests (4): RFC8203-2-1, RFC8203-2-3, RFC8203-6-1, RFC8203-2-4
Annotated (including scoped evidence) (1): RFC8203-2-2
Requirements
| Requirement | Level | Section | Tests |
|---|---|---|---|
RFC8203-2-1 | Subcode: the Error Subcode value MUST be one of the following values: 2 ("Administrative Shutdown") or 4 ("Administrative Reset"). (§2) | ||
| MUST | 2 - Shutdown Communication | ||
RFC8203-2-2 | The length value MUST range from 0 to 128 inclusive. (§2) | ||
| MUST | 2 - Shutdown Communication | negative
no testno negative test{single-polarity}: the sender enforces the 0-128 range -- BuildShutdownData truncates a longer message to 128 at a UTF-8 boundary (internal/component/bgp/message/notification.go:312) -- but the receiver deliberately follows RFC 9003, which obsoletes RFC 8203 and raised the cap to 255 (ShutdownMessage reads a 1-byte length up to 255, notification.go:268-284), so ze intentionally does not reject a 129-255 length on receive and there is no over-128-rejected behavior to assert |
|
RFC8203-2-3 | Shutdown Communication: to support international characters, the Shutdown Communication field MUST be encoded using UTF-8. (§2) | ||
| MUST | 2 - Shutdown Communication | ||
RFC8203-6-1 | UTF-8 "Shortest Form" encoding is REQUIRED to guard against the technical issues outlined in [UTR36]. (§6) | ||
| MUST | 6 - Security Considerations | ||
RFC8203-2-4 | A receiving BGP speaker MUST NOT interpret invalid UTF-8 sequences. (§2) | ||
| MUST NOT | 2 - Shutdown Communication | ||
RFC8203-2-5 | Mechanisms concerning the reporting of information contained in the Shutdown Communication are implementation specific but SHOULD include methods such as Syslog [RFC5424]. (§2) | ||
| SHOULD | 2 - Shutdown Communication | positive
no testno positive testnegative
no testno negative test |
|
RFC8203-4-1 | If a Shutdown Communication with an invalid Length value, or an invalid UTF-8 sequence is received, a message indicating this event SHOULD be logged for the attention of the operator. (§4) | ||
| SHOULD | 4 - Error Handling | positive
no testno positive testnegative
no testno negative test |
|
RFC8203-2-6 | If a BGP speaker decides to terminate its session with a BGP neighbor, and it sends a NOTIFICATION message with the Error Code "Cease" and Error Subcode "Administrative Shutdown" or "Administrative Reset" [RFC4486], it MAY include an UTF-8 encoded string. (§2) | ||
| MAY | 2 - Shutdown Communication | positive
no testno positive testnegative
no testno negative test |
|
RFC8203-4-2 | An erroneous or malformed Shutdown Communication itself MAY be logged in a hexdump format. (§4) | ||
| MAY | 4 - Error Handling | positive
no testno positive testnegative
no testno negative test |
|
Gaps and untested MUSTs
RFC 8203 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.
RFC8203-2-1
Subcode: the Error Subcode value MUST be one of the following values: 2 ("Administrative Shutdown") or 4 ("Administrative Reset"). (§2)
Audit verdict: enforced (the tests do what the requirement demands), fresh. Sender side: TestRFC8203ShutdownCommunicationOnlyUnderSubcode2Or4 requires BuildCeaseData to return length+message under subcodes 2 and 4 and nothing under 0,1,3,5..10. BuildCeaseData is the teardown's only Cease-data builder (session_connection.go, behaviour unchanged); other Cease senders (max-prefix, collision, policy) send their own non-shutdown data. Judge break (return the message for every subcode): red.
| Polarity | Test | Kind and tier | Proof state |
|---|---|---|---|
| negative | TestRFC8203Subcode |
unit/verify | unproven |
| negative | TestRFC8203ShutdownCommunicationOnlyUnderSubcode2Or4 |
unit/verify | revert, verified |
| positive | TestRFC8203Subcode |
unit/verify | unproven |
| positive | TestRFC8203ShutdownCommunicationOnlyUnderSubcode2Or4 |
unit/verify | revert, verified |
RFC8203-2-2
The length value MUST range from 0 to 128 inclusive. (§2)
Audit verdict: enforced (the tests do what the requirement demands), fresh. Forbidden behaviour: Ze emitting a Length above 128. TestRFC8203LengthCap feeds a 200-byte message to BuildShutdownData and require.Equal(byte(128), data[0]) goes red if the cap is lost. Receive-side 129-255 acceptance follows RFC 9003 and is covered by the row's {single-polarity: positive} marker.
| Polarity | Test | Kind and tier | Proof state |
|---|---|---|---|
| positive | TestRFC8203LengthCap |
unit/verify | unproven |
RFC8203-2-3
Shutdown Communication: to support international characters, the Shutdown Communication field MUST be encoded using UTF-8. (§2)
Audit verdict: enforced (the tests do what the requirement demands), fresh. TestRFC8203ShutdownCommunicationSentAsShortestFormUTF8: valid 2/3/4-octet UTF-8 sent octet-exact; stray octets, overlong, surrogate and a 128-octet cut inside a character each yield a field with a consistent length octet, utf8.Valid and <=128 octets; overlong input sent as 'xy'.
| Polarity | Test | Kind and tier | Proof state |
|---|---|---|---|
| negative | TestRFC8203UTF8Invalid |
unit/verify | unproven |
| negative | TestRFC8203ShutdownCommunicationSentAsShortestFormUTF8 |
unit/verify | revert, verified |
| positive | TestRFC8203UTF8Valid |
unit/verify | unproven |
| positive | TestRFC8203ShutdownCommunicationSentAsShortestFormUTF8 |
unit/verify | revert, verified |
RFC8203-6-1
UTF-8 "Shortest Form" encoding is REQUIRED to guard against the technical issues outlined in [UTR36]. (§6)
Audit verdict: enforced (the tests do what the requirement demands), fresh. Same unit: U+00E9 shortest form sent unchanged; the overlong 0xC0 0xAF and surrogate 0xED 0xA0 0x80 never reach the field (utf8.Valid refuses both forms, and the overlong case is asserted exact). Receive side held by the HEAD units.
| Polarity | Test | Kind and tier | Proof state |
|---|---|---|---|
| negative | TestRFC8203ShortestFormUTF8 |
unit/verify | unproven |
| negative | TestRFC8203ShutdownCommunicationSentAsShortestFormUTF8 |
unit/verify | revert, verified |
| positive | TestRFC8203ShortestFormUTF8 |
unit/verify | unproven |
| positive | TestRFC8203ShutdownCommunicationSentAsShortestFormUTF8 |
unit/verify | revert, verified |
RFC8203-2-4
A receiving BGP speaker MUST NOT interpret invalid UTF-8 sequences. (§2)
Audit verdict: enforced (the tests do what the requirement demands), fresh. Forbidden behaviour: the receiver interpreting an invalid UTF-8 sequence. TestRFC8203UTF8Invalid feeds 0xff 0xfe 0xfd and require.Error plus require.Empty(msg) go red if ShutdownMessage returns decoded text. The negative tag TestRFC8203UTF8Valid proves valid multibyte text is still interpreted (require.Equal "日本語").
| Polarity | Test | Kind and tier | Proof state |
|---|---|---|---|
| negative | TestRFC8203UTF8Valid |
unit/verify | unproven |
| positive | TestRFC8203UTF8Invalid |
unit/verify | unproven |
Extraction sign-off
| Field | Value |
|---|---|
| Reviewer | ze-work agent, spec-rfcgate-6, rfc8203 |
| Signed off | 2026-08-31 |
| Register | rfc2119 |
| Source | rfc/full/rfc8203.txt |
| Source fingerprint | f4dedca562743ae1 |
| Record | rfc/extraction/rfc8203.json |
| Mapped sentences | 5 |
| Declined as scope | 0 |
| 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 restates the Introduction and directs no speaker. |
1 |
Introduction | 0 | walked | Introduction. Indicative prose: correlating a session teardown with an offline notice is troublesome, and this document updates RFC 4486 by specifying a mechanism to carry a short freeform UTF-8 message in a Cease NOTIFICATION. It states what the document does, never what a speaker must do. |
1.1 |
Requirements Language | 0 | walked | Requirements Language. The BCP 14 key-words paragraph, which also states that the key words bind only when they appear in all capitals. It tells a reader how to read the other sections and binds no speaker, which is why the derivation excludes it from the site inventory. |
2 |
Shutdown Communication | 4 | walked | Shutdown Communication. The document's whole normative surface for the wire format: four capitalised MUST-level sites, mapped below to RFC8203-2-1 through RFC8203-2-4. Its remaining directives are the opening MAY (a speaker MAY include a UTF-8 string) and the closing SHOULD (reporting mechanisms SHOULD include methods such as Syslog); both are the unsourced ids below. Three sentences the site scan cannot see are descriptive, not obligations: the Figure 1 field diagram and its Error Code 6, the note that a multibyte Shutdown Communication holds fewer characters than the length value, and "This field is not NUL terminated", which describes the field rather than directing a receiver. Ze's receiver already reads exactly the length-prefixed extent and never scans for a terminator (Notification.ShutdownMessage, internal/component/bgp/message/notification.go). |
3 |
Operational Considerations | 0 | walked | Operational Considerations. Encourages operators to describe the reason for the shutdown and works through the "[TICKET-1-1438367390] software upgrade" example. Advice to an operator writing a message, with no RFC 2119 keyword and no directive to an implementation. |
4 |
Error Handling | 0 | walked | Error Handling. Two directives, neither MUST-level and neither visible to the site scan: an invalid Length value or an invalid UTF-8 sequence SHOULD be logged for the attention of the operator, and the malformed Shutdown Communication MAY be logged in a hexdump format. Both are the unsourced ids below. |
5 |
IANA Considerations | 0 | skipped (iana) | IANA Considerations. Records that IANA references this document, in addition to RFC 4486, for subcodes 2 and 4 in the "Cease NOTIFICATION message subcodes" registry. Binds IANA, not a speaker. |
6 |
Security Considerations | 1 | walked | Security Considerations. Carries one capitalised site, the REQUIRED UTF-8 "Shortest Form" encoding, mapped below to RFC8203-6-1. This is the ONLY place RFC 8203 states shortest form; its section 2 does not, which is a real difference from RFC 9003, where the same sentence appears in both sections. The rest is risk narration: the Unicode issues of UTR36, the syslog-injection risk the 128-octet limit is said to limit, forgery and snooping without an integrity or confidentiality transport, and the RFC 6973 section 6.1 data-minimization advice. Each is stated as advice to implementers and operators, with no keyword. |
7 |
References | 0 | skipped (references) | References. Section header for the two reference lists below. |
7.1 |
not stated | 0 | skipped (references) | Normative References: RFC 2119, RFC 3629, RFC 4271, RFC 4486, RFC 8174. |
7.2 |
Informative References: RFC 4272, RFC 5424, RFC 6973, UTR36 | 0 | skipped (references) | Informative References: RFC 4272, RFC 5424, RFC 6973, UTR36. |
Excluded sentences
The walk over RFC 8203 declined no sentence: every site it found is mapped to a requirement.
Superseded
No document obsoletes RFC 8203, so its obligations are stated where they were written.