Internet DRAFT - draft-spaghetti-grow-nrtm-v4
draft-spaghetti-grow-nrtm-v4
GROW S. Romijn
Internet-Draft Reliably Coded
Intended status: Standards Track J. Snijders
Expires: 7 August 2022 Fastly
E. Shryane
RIPE NCC
S. Konstantaras
AMS-IX
3 February 2022
Near Real Time Mirroring (NRTM) version 4
draft-spaghetti-grow-nrtm-v4-00
Abstract
This document specifies a one-way synchronization protocol for
Internet Routing Registry (IRR) records. The protocol allows
instances of IRR database servers to mirror IRR records, specified in
in the Routing Policy Specification Language (RPSL), between each
other.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 7 August 2022.
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Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Informal overview . . . . . . . . . . . . . . . . . . . . . . 3
3. Mirror server use . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Key Configuration and the Database Configuration File . . 5
3.2. Snapshot Initialization . . . . . . . . . . . . . . . . . 5
3.3. Publishing updates . . . . . . . . . . . . . . . . . . . 6
3.3.1. Delta Files . . . . . . . . . . . . . . . . . . . . . 6
3.3.2. Snapshot Files . . . . . . . . . . . . . . . . . . . 7
3.3.3. Update Notification File . . . . . . . . . . . . . . 7
3.3.4. Publication Policy Restrictions . . . . . . . . . . . 8
4. Mirror client use . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Configuration . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Initialization from snapshot . . . . . . . . . . . . . . 8
4.3. Processing Delta Files . . . . . . . . . . . . . . . . . 9
4.4. Signature and Staleness Verification . . . . . . . . . . 10
4.5. Policy Restrictions . . . . . . . . . . . . . . . . . . . 10
5. Database Configuration File . . . . . . . . . . . . . . . . . 10
5.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2. Cache concerns . . . . . . . . . . . . . . . . . . . . . 11
5.3. File format and validation . . . . . . . . . . . . . . . 11
6. Update Notification File . . . . . . . . . . . . . . . . . . 12
6.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.2. Cache concerns . . . . . . . . . . . . . . . . . . . . . 12
6.3. File format and validation . . . . . . . . . . . . . . . 12
6.4. Signature . . . . . . . . . . . . . . . . . . . . . . . . 14
7. Snapshot File . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.2. Cache Concerns . . . . . . . . . . . . . . . . . . . . . 14
7.3. File format and validation . . . . . . . . . . . . . . . 15
8. Delta File . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.1. Purpose . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.2. Cache Concerns . . . . . . . . . . . . . . . . . . . . . 16
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8.3. File format and validation . . . . . . . . . . . . . . . 16
9. Operational Considerations . . . . . . . . . . . . . . . . . 18
9.1. IRR object Validation . . . . . . . . . . . . . . . . . . 18
9.2. Intermediate mirror instances . . . . . . . . . . . . . . 19
9.3. Reading from local files . . . . . . . . . . . . . . . . 19
9.4. Public key rotation . . . . . . . . . . . . . . . . . . . 19
10. Security Considerations . . . . . . . . . . . . . . . . . . . 20
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
13.1. Normative References . . . . . . . . . . . . . . . . . . 20
13.2. Informative References . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction
The Internet Routing Registry (IRR) consists of several different IRR
Databases, each storing objects in the Routing Policy Specification
Language (RPSL). About a dozen larger IRR Databases are well known
and widely used, operated by different organisations, like RIRs and
some large network operators. IRR objects serve many purposes,
ranging from manual research by operators to automated network
configuration and filtering.
Most of these well known IRR Databases mirror IRR objects from some
others, so that queries run against these instances provide a
comprehensive view. Some parties also mirror IRR Databases to
private IRR server instances, to reduce latency in queries, analyze
IRR objects, or other purposes.
NRTM version 4 is a protocol for IRR mirroring, designed to address
issues in existing IRR Database mirroring protocols. In NRTMv4, IRR
Databases publish their records on a HTTPS endpoint, with periodic
Snapshot Files and regular Delta Files. Signing allows integrity
checks. By only generating files once and publishing them over
HTTPS, scalability is dramatically improved. It borrows some
concepts in [RFC8182], as there are overlaps between the two
protocols.
2. Informal overview
In NRTMv4, a mirror server is an instance of IRR Database software
that has a database of IRR objects and publishes them to allow
mirroring by others. This can be retrieved by mirror clients, which
then load the IRR objects into their local storage.
Publication consists of three different files:
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* A single Update Notification File. This specifies the current
Database version and locations of the Snapshot File and Delta
Files. Additionally, there is an Update Notification Signature
File, used to verify the authenticity of the Update Notification
File.
* A single active Snapshot File. This contains all published IRR
objects at a particular version. The mirror server periodically
generates a new snapshot.
* Zero or more Delta Files. These contain the changes between two
database version numbers.
Mirror clients initially retrieve the small Update Notification File
and a Snapshot File, from which they initialize their local copy of
the Database. After that, mirror clients only retrieve the Update
Notification File periodically to determine whether there are any
changes, and then retrieve only the relevant Delta Files, if any.
This minimizes data transfer. Deltas have sequential versions.
A mirror client is configured from a Database Configuration File on a
well-known URL, which contains a public signing key which it uses to
verify the Update Notification File, which in turn contains hashes of
all the Snapshot and Delta Files.
Upon initialization, the mirror server generates a session ID for the
Database. This allows long term caching and used by the client to
determine that the Delta Files continue to form a full set of changes
allowing an update to the latest version. If the mirror server loses
partial history, or the mirror client starts mirroring from a
different server, the session ID change will force a full reload from
the latest Snapshot File, ensuring there are no accidental mirroring
gaps.
Mirror servers can use caching to reduce their load, particularly
because snapshots and deltas are immutable for a given session ID and
version number. These are also the largest files. Update
Notification Files may not be cached for longer than one minute, but
are fairly small.
Note that in NRTMv4, a contiguous version number is used for the
Database version and Delta Files. This is different and unrelated to
the serial in NRTMv3. NRTMv3 serials refer to a single change to a
single object, whereas a NRTMv4 version refers to one delta, possibly
containing multiple changes to multiple objects. NRTMv3 serials can
also contain gaps, NRTMv4 versions may not.
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3. Mirror server use
3.1. Key Configuration and the Database Configuration File
_REMOVE BEFORE PUBLICATION: this whole section is wide open to
suggestions / ideas_
When enabling NRTMv4 publication for an IRR Database, the operator
MUST generate and configure a private Ed25519 [RFC8032] key. Then,
the operator MUST publish the public key, the name of the IRR
Database and the URL of the Update Notification File in the Database
Configuration File. This is a JSON file on a well-known URI on the
"irr-nrtm.json" suffix on the operator's authoritative domain name
[RFC8615].
The authoritative domain name is the domain which is generally known
by the IRR community to belong to the operator of the IRR Database.
Note that the Update Notification File, Snapshot File and Delta Files
MAY also be hosted on the authoritative domain, or an entirely
different host or domain.
It is RECOMMENDED that implementations provide easily accessible
tools for operators to generate new Ed25519 keys to enter into their
configuration, and propose a Database Configuration File from the
current configuration. Configuration options SHOULD be clearly named
to indicate that they are private keys.
3.2. Snapshot Initialization
A mirror server MUST follow the initialization steps upon the first
export for an IRR Database by that mirror server, or if the server
lost history and can not reliably produce a continuous set of deltas
from a previous state.
In other words, either the mirror server guarantees that clients
following the deltas have a correct and complete view, or MUST
reinitialize, which will force clients to reinitialize as well.
Initialization consists of these actions:
* The mirror server MUST generate a new session ID. This MUST be a
random v4 UUID [RFC4122] and MUST be the same across all client
sessions. However, if the server instance is serving two
different IRR databases (e.g. RIPE IRR and RIPE-NONAUTH IRR),
then it MUST generate two session IDs, each one associated with
the different database.
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* The server MUST generate a snapshot for version number one. This
may contain an empty array of objects if the IRR Database is
currently empty.
* The server MUST generate a new Update Notification File with the
new session ID, a reference to the new snapshot, and no deltas.
* The Update Notification Signature File MUST be updated for the new
Update Notification File contents.
Note that session IDs, versions and all files always relate to a
specific IRR Database. For example, a mirror server publishing
NRTMv4 for RIPE and RIPE-NONAUTH, will generate two Update
Notification Files, referring two Snapshot Files, and two sets of
Delta Files each with contiguous version numbers - all completely
independent to each other, with different session IDs. This applies
even if the same IRR server instance produces both.
3.3. Publishing updates
3.3.1. Delta Files
Changes to IRR objects MUST be recorded in Delta Files. One Delta
File can contain multiple changes.
Updates are generated as follows:
* A mirror server MUST publish a Delta File approximately every
minute, if there have been changes to IRR objects in that time
frame.
* If multiple changes have occurred within the time frame that would
cancel each other out, like an addition and immediate deletion of
the same object, the mirror server MUST still include all these
changes.
* If a mirror server is lagging in production of Delta Files, such
as after an initialization or server downtime, it MUST generate
one larger "catch up" Delta File, rather than individual Delta
Files for every one minute window.
* A new Delta File MUST be generated with a new version, one greater
than the last Delta File version, or one greater than the last
Snapshot File version if there were no prior deltas at all.
* The Delta File MUST include all changes that happened during the
time frame, in the order in which they occurred.
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* The URL where the Delta File is published MUST contain the session
ID and version number to allow it to be indefinitely cached. It
MUST also contain a random value that can not be predicted before
publication, to counter negative caching issues.
* After generating a new Delta File, a mirror server MUST remove all
Delta Files older than 24 hours.
* The Update Notification File MUST be updated to include the new
Delta File and update the database version.
3.3.2. Snapshot Files
Snapshot Files after initialization are generated as follows:
* The mirror server MUST generate a new Snapshot File between once
per hour and once per day, if there have been changes to the IRR
objects.
* The version number of the new snapshot MUST be equal to the last
Delta File version.
* If there have been no changes to the IRR objects since the last
snapshot, the mirror server MUST NOT generate a new snapshot.
* The URL where the Snapshot File is published MUST contain the
session ID and version number to allow it to be indefinitely
cached. It MUST also contain a random value that can not be
predicted before publication, to counter negative caching issues.
* The Update Notification File MUST be updated to include the new
snapshot, if one was generated.
3.3.3. Update Notification File
The Update Notification File must be updated when a new Delta or
Snapshot File is published and, even if there have been no changes,
at least every 24 hours.
After any update to the Update Notification file, the mirror server
MUST also update the Update Notification Signature File for the new
Update Notification File contents.
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3.3.4. Publication Policy Restrictions
A mirror server MAY have a policy that restricts the publication of
certain IRR objects or attributes, or modifies these before
publication. Typical scenarios for this include preventing the
distribution of certain personal data or password hashes, or
excluding objects which do not meet validation rules like RPKI
consistency. It is RECOMMENDED to modify objects in such a way that
this change is evident to humans reading the object text, for example
by adding remark lines or comments.
Mirror servers are RECOMMENDED to remove password hashes from the
auth lines in mntner objects, as they have little use beyond the
authoritative server, and their publication may be a security risk.
If a mirror server has a policy that restricts or modifies object
publication, this MUST be applied consistently to Snapshot Files and
Delta Files from the moment the policy is enacted or modified.
4. Mirror client use
4.1. Configuration
_REMOVE BEFORE PUBLICATION: this whole section is wide open to
suggestions / ideas_
Mirror clients are configured with the name of an IRR Database to
mirror and the domain considered authoritative by the mirror client
operator, which hosts the Database Configuration File. The mirror
client MUST retrieve this file, look for an entry under the expected
IRR Database name, and read the Update Notification File URL and the
public key. The mirror client MUST only allow retrieval of this file
over HTTPS.
The mirror client MUST retrieve the Database Configuration File every
24 hours, and update its local configuration if any settings in the
file have changed.
4.2. Initialization from snapshot
Clients MUST initialize from a Snapshot File when initially
configured or if they are not able to update their local data from
the provided Delta Files:
* The client MUST retrieve the Update Notification File.
* The client MUST verify that the source attribute in the Update
Notification File matches the configured IRR Database name.
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* The client MUST retrieve the Snapshot File and load the objects
into its local storage.
* The mirror client MUST verify that the hash of the Snapshot File
matches the hash in the Update Notification File that referenced
it. In case of a mismatch of this hash, the file MUST be
rejected.
* The client MUST record the configured authoritative domain, the
session_id and version from the Update Notification File.
4.3. Processing Delta Files
If a mirror client has previously initialized from a snapshot:
* The client MUST verify that the configured Update Notification
File URL matches the previously known URL. If this does not
match, the client MUST reinitialize from the Snapshot File, using
the new Update Notification File URL.
* The client MUST retrieve the Update Notification File.
* The client MUST verify that the session ID matches the previously
known session ID. If this does not match, the client MUST
reinitialize from the snapshot.
* The client MUST verify that the Update Notification File version
is the same or higher than the client's current most recent
version, to the latest version in the Update Notification File.
If not, the Update Notification File MUST be rejected.
* The client MUST verify that the Update Notification File contains
one contiguous set of Delta File versions from the client's
current most recent version up to the latest version in the Update
Notification File. If this is not found, the client MUST
reinitialize from the snapshot.
* The client MUST retrieve all Delta Files for versions since the
client's last known version, if there are any.
* The mirror client MUST verify that the hash of each newly
downloaded Delta File matches the hash in the Update Notification
File that referenced it. In case of a mismatch of this hash, the
Delta File MUST be rejected.
* The client MUST process all changes in the Delta Files in order:
lowest Delta File version number first, and in the order of the
changes list in the Delta File.
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* The client MUST update its record of the most recent version to
the version of the Update Notification File.
If the Update Notification File or one of the Delta Files is
rejected, the mirror client MUST NOT process any newer Deltas than
those that are valid and have been successfully verified.
4.4. Signature and Staleness Verification
Every time a mirror client retrieves a new version of the Update
Notification File, it MUST retrieve and verify the Update
Notification Signature File. The signature MUST be valid for the
configured public key for the contents of the Update Notification
File.
If the signature does not match, the mirror client MUST reject the
Update Notification File and retrieve the Database Configuration
File, as a mismatch may be caused by a key rotation by the mirror
server operator. If the Database Configuration File contains a new
public key, the mirror client will attempt to use that key for
signature verification instead.
A mirror client can use the generation timestamp in the Update
Notification File to check whether the file is stale, as the mirror
server must update this file at least every 24 hours. If the
generation timestamp is more than 24 hours ago, the file is stale and
the mirror client SHOULD warn the operator in log messages or other
alerting, but MAY continue to process it otherwise.
4.5. Policy Restrictions
A mirror client MAY have a policy that restricts the processing of
objects to certain object classes, or other limitations on which
objects it processes.
If a mirror client has a policy that restricts object processing,
this MUST be applied consistently to Snapshot Files and Delta Files
from the moment the policy is enacted or modified.
5. Database Configuration File
_REMOVE BEFORE PUBLICATION: this whole section is wide open to
suggestions / ideas_
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5.1. Purpose
The Database Configuration File is provided by the IRR Database
operator as configuration information for mirror clients. For each
IRR Database run by an operator, it contains the current signing key,
Snapshot Notification File URL and the IRR Database name. This JSON
file MUST be placed on a well-known URI [RFC8615] on the "irr-
nrtm.json" suffix on the authoritative domain name of the IRR
Database operator and must be available over HTTPS.
The operator MUST update this file if any of these configuration
details change.
5.2. Cache concerns
A mirror server may use caching infrastructure to cache the Database
Configuration File and reduce the load of HTTPS requests. Unlike
some of the other files, this file is both very small and quite
rarely retrieved, limiting the need for and benefits of caching.
Since this file is used by mirror clients to determine the current
signing key, this SHOULD not cached for longer than one minute to
support key rotations.
5.3. File format and validation
Example Database Configuration File:
[
{
"source": "EXAMPLE-A",
"update_notification": "https://example.net/db/nrtmv4/example-a/notification.json",
"key": "96..ae"
},
{
"source": "EXAMPLE-B",
"update_notification": "https://cdn.example.com/db/nrtmv4/example-b/notification.json",
"key": "b6..3d",
}
]
Note: the keys in this example are shortened because of formatting.
The following validation rules MUST be observed when creating or
parsing Database Configuration Files:
* The source contains the IRR Database name and MUST be a valid IRR
object name [RFC2622], which matches the source in the referred
Update Notification File.
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* The update_notification MUST be the HTTPS URL of the Update
Notification File.
* The key MUST be the Ed25519 [RFC8032] public key encoded in base64
[RFC4648], which the mirror server uses to sign the Update
Notification File.
* The file MUST contain at least one entry for an IRR Database, but
MAY contain multiple with different source values.
* The file MUST only contain US-ASCII characters.
6. Update Notification File
6.1. Purpose
The Update Notification File is generated by the mirror server and
used by mirror clients to discover whether any changes exist between
the state of the IRR mirror server and of the mirror client's. It
also describes the location of the Snapshot File and incremental
Delta Files. Finally, the generation timestamp can be used to detect
whether the file is stale.
The mirror server MUST generate a new Update Notification File every
time there are new deltas or snapshots and, even if there have been
no changes, at least every 24 hours.
6.2. Cache concerns
A mirror server may use caching infrastructure to cache the Update
Notification File and reduce the load of HTTPS requests.
However, since this file is used by mirror clients to determine
whether any updates are available, the mirror server SHOULD ensure
that this file is not cached for longer than one minute. An
exception to this rule is that it is better to serve a stale Update
Notification File rather than no Update Notification File.
6.3. File format and validation
Example Update Notification File:
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{
"nrtm_version": 4,
"timestamp": "2022-01-00T15:00:00Z",
"type": "notification",
"source": "EXAMPLE",
"session_id": "ca128382-78d9-41d1-8927-1ecef15275be",
"version": 3,
"snapshot": {
"version": 2,
"url": "https://example.com/ca128382-78d9-41d1-8927-1ecef15275be/nrtm-snapshot.2.047595d0fae972fbed0c51b4a41c7a349e0c47bb.json",
"hash": "9a..86"
}
"deltas": [
{
"version": 1,
"url": "https://example.com/ca128382-78d9-41d1-8927-1ecef15275be/nrtm-delta.1.784a2a65aba22e001fd25a1b9e8544e058fbc703.json",
"hash": "62..a2"
}
{
"version": 2,
"url": "https://example.com/ca128382-78d9-41d1-8927-1ecef15275be/nrtm-delta.2.0f681f07cfab5611f3681bf030ec9f6fa3442fb0.json",
"hash": "25..9a"
}
{
"version": 3,
"url": "https://example.com/ca128382-78d9-41d1-8927-1ecef15275be/nrtm-delta.3.d9c194acbb2cb0d4088c9d8a25d5871cdd802c79.json",
"hash": "b4..13"
}
]
}
Note: hash values in this example are shortened because of
formatting.
The following validation rules MUST be observed when creating or
parsing Update Notification Files:
* The nrtm_version MUST be 4.
* The timestamp MUST be an [RFC3339] timestamp.
* The type MUST be "notification".
* The source MUST be a valid IRR object name [RFC2622].
* The session_id attribute MUST be a random v4 UUID [RFC4122] unique
to this session for this source.
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* The version MUST be an unsigned positive integer and be equal to
the highest version of the deltas and snapshot.
* The file MUST contain exactly one snapshot.
* The file MAY contain one or more deltas.
* The deltas MUST have a sequential contiguous set of version
numbers.
* Each snapshot and delta element MUST have a version, HTTPS URL and
hash attribute.
* The hash attribute in snapshot and delta elements MUST be the
hexadecimal encoding of the SHA-256 hash [SHS] of the referenced
file. The mirror client MUST verify this hash when the file is
retrieved and reject the file if the hash does not match.
* The file MUST only contain US-ASCII characters.
6.4. Signature
The contents of Update Notification File MUST be signed using Ed25519
[RFC8032]. The public key for this signature is published in the
Database Configuration File. The signature of the Update
Notification File MUST be published under the same path as the Update
Notification File, appending ".sig".
7. Snapshot File
7.1. Purpose
The Snapshot File reflects the complete and current contents of all
IRR objects in an IRR Database. Mirror clients MUST use this to
initialize their local copy of the IRR Database.
7.2. Cache Concerns
A snapshot reflects the content of the IRR Database at a specific
point in time; for that reason, it can be considered immutable data.
Snapshot Files MUST be published at a URL that is unique to the
specific session and version. The URL MUST also contain a random
value that can not be predicted before publication, to counter
negative caching issues.
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Because these files never change, they MAY be cached indefinitely.
However, as snapshots are large and old snapshots will no longer be
referred by newer Update Notification Files, it is RECOMMENDED that a
limited interval is used in the order of hours or days.
To avoid race conditions where a mirror client retrieves an Update
Notification File moments before it's updated, mirror servers SHOULD
retain old Snapshot Files for at least 5 minutes after a new Update
Notification File is published.
7.3. File format and validation
Example Snapshot File:
{
"nrtm_version": 4,
"type": "snapshot",
"source": "EXAMPLE",
"session_id": "ca128382-78d9-41d1-8927-1ecef15275be",
"version": 2,
"objects": [
"route: 192.0.2.0/24\norigin: AS65530\nsource: EXAMPLE",
"route: 2001:db8::/32\norigin: AS65530\nsource: EXAMPLE"
]
}
Note: IRR object texts in this example are shortened because of
formatting.
The following validation rules MUST be observed when creating or
parsing Snapshot Files:
* The nrtm_version MUST be 4.
* The type MUST be "snapshot".
* The source MUST match the source in the Update Notification File.
* The session_id attribute MUST match the session_id in the Update
Notification File.
* The version MUST be an unsigned positive integer, matching the
Update Notification File entry for this snapshot.
* The objects attribute MUST be an array of zero or more elements,
each containing a string representation of an IRR object. The
string representation MUST be encoded in UTF-8 in Quoted-Printable
encoding [RFC2045].
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* The source attribute in the IRR object texts MUST match the source
attribute of the Snapshot File.
* The file MUST only contain US-ASCII characters.
8. Delta File
8.1. Purpose
A Delta File contains all changes for exactly one incremental update
of the IRR Database. It may include new, modified and deleted
objects. Delta Files can contain multiple alterations to multiple
objects.
8.2. Cache Concerns
Deltas reflect the difference in content of the IRR Database from one
version to another; for that reason, it can be considered immutable
data. Delta Files MUST be published at a URL that is unique to the
specific session and version. The URL MUST also contain a random
value that can not be predicted before publication, to counter
negative caching issues.
To avoid race conditions where a mirror client retrieves an Update
Notification File moments before it's updated, mirror servers SHOULD
retain old Delta Files for at least 5 minutes after a new Update
Notification File is published that no longer contains these Delta
Files.
8.3. File format and validation
Example Delta File:
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{
"nrtm_version": 4,
"type": "delta",
"source": "EXAMPLE",
"session_id": "ca128382-78d9-41d1-8927-1ecef15275be",
"version": 3,
"changes": [
{
"action": "delete",
"existing_object": "route: 192.0.2.0/24\norigin: AS65530\nsource: EXAMPLE",
}
{
"action": "add_modify",
"new_object": "route: 2001:db8::/32\norigin: AS65530\nsource: EXAMPLE",
}
]
}
Note: IRR object texts in this example are shortened because of
formatting.
The following validation rules MUST be observed when creating or
parsing Delta Files:
* The nrtm_version MUST be 4.
* The type MUST be "delta".
* The source MUST match the source in the Update Notification File.
* The session_id attribute MUST match the session_id in the Update
Notification File.
* The version MUST be an unsigned positive integer, matching the
Update Notification File entry for this delta.
* The changes attribute MUST be an array of one or more elements,
each having:
- An action attribute, which is either "delete" for object
deletions, or "add_modify" for additions or modifications.
- If action is "delete": an existing_object attribute with the
RPSL text of the last version of the object prior to deletion.
- If action is "add_modify": a new_object attribute with the RPSL
text of the new version of the object.
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- The string representation of the objects MUST be encoded in
UTF-8 in Quoted-Printable encoding [RFC2045].
* The source attribute in the IRR object texts MUST match the source
attribute of the Delta File.
* The file MUST only contain US-ASCII characters.
9. Operational Considerations
9.1. IRR object Validation
Throughout the years, various implementations of IRR servers have
taken liberties with the various RFCs regarding RPSL.
Implementations have introduced different new object classes,
attributes and validation rules. Current IRR Databases also contain
legacy objects which were created under different validation rules.
In practice, there is no uniformly implemented standard for RPSL, but
merely rough outlines partially documented in different places.
This has the potential to create interoperability issues. Some are
addressed by NRTMv4, like having a consistent character set when
mirroring data between implementations. However, some issues can not
be addressed in this way, such as one implementation introducing a
new object class that is entirely unknown to another implementation.
A mirror client SHOULD be able to handle unknown object classes and
objects that are invalid according to its own validation rules, which
may mean simply discarding them, without rejecting remaining objects
or preventing future updates.
It is RECOMMENDED for mirror clients to log these cases, particularly
those where an object was discarded due to violating validation
rules. These cases create an inconsistency between the IRR objects
of the server and client, and logs facilitate later analysis.
It is RECOMMENDED for mirror clients to be flexible where possible
and reasonable when applying their own validation rules to IRR
objects retrieved from mirror servers. For example, a route object
with an origin attribute that is not a valid AS number can't be
usefully interpreted. There is no way for an IRR server to correctly
parse and index such an object. However, a route-set object whose
name does not start with "RS-" [RFC2622], or an inetnum with an
unknown extra "org" attribute, still allows the mirror client to
interpret it unambiguously even if it does not meet the mirror
client's own validation rules for authoritative records.
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9.2. Intermediate mirror instances
An IRR Database generally has a single authoritative source. In some
cases, an instance run by a third party will function as a kind of
intermediate: both being a mirror client, mirroring IRR objects from
the authoritative source, and simultaneously function as a mirror
server to yet another mirror client.
There are various operational reasons for such a setup, such as the
intermediate filtering certain records. Regardless of the reason,
the mirror client and server function of an IRR server must be
treated as separate processes. In particular, this means they MUST
have separate session IDs. The intermediate server MUST NOT
republish the same files it retrieved from the authoritative source
with the same session ID.
9.3. Reading from local files
In the typical use case for NRTMv4, a mirror client retrieves files
from an HTTPS endpoint. However, implementations MAY also support
reading from files on the local filesystem instead, for when
operators want to use a different method to retrieve or distribute
the files. When reading from local files, mirror clients SHOULD
still follow all validation rules, including the validation of the
signature and hashes.
9.4. Public key rotation
It is RECOMMENDED that IRR Database operators rotate the signing key
on their mirror server about once per year. To support this, the
mirror server implementation MUST provide a way for operators to
immediately generate a new Update Notification File on demand. To
perform the rotation, the operator then:
* Generates a new key.
* Prepares a new Database Configuration File with the new public
key.
* Configures the new private key in the mirror server software.
* Makes the mirror server software generate a new Update
Notification File.
* Publishes the new Database Configuration File.
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Mirror clients will load the Update Notification File, find the
signature to be invalid, retrieve the Database Configuration File and
configure the new key. Note that key rotation will briefly but
significantly increase the retrievals of the Database Configuration
File, as almost every current mirror client will retrieve it within
the minute after publication of the new Update Notification File.
10. Security Considerations
IRR objects serve many purposes, including automated network
configuration and filtering. Manipulation of IRR objects can
therefore have a significant security impact. However, security in
existing protocols is mostly absent.
Before NRTMv4, the most common protocols for IRR Database mirroring
are FTP for retrieving full snapshots, and NRTM version 3 for
retrieving later changes. There are no provisions for integrity or
authenticity, and there are various scenarios where mirroring may not
be reliable.
NRTMv4 requires integrity verification. The Delta and Snapshot Files
are verified using the SHA-256 hash in the Update Notification File,
and the Update Notification File is verified using its signature
file. Additionally, the channel security offered by HTTPS further
limits security risks.
By allowing publication on any HTTPS endpoint, NRTMv4 allows for
extensive scaling, and there are many existing techniques and
services to protect against denial-of-service attacks. In contrast,
NRTMv3 required mirror clients to directly query the IRR server
instance with special whois queries. This scales poorly, and there
are no standard protections against denial-of-service available.
The HTTPS endpoint used for NRTMv4 MUST be configured according to
the best practices in [RFC7525].
11. IANA Considerations
This document requests IANA to ...
12. Acknowledgments
The authors would like to thank ... and ... for their helpful
review of this document.
13. References
13.1. Normative References
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[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message
Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
<https://www.rfc-editor.org/info/rfc2045>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2622] Alaettinoglu, C., Villamizar, C., Gerich, E., Kessens, D.,
Meyer, D., Bates, T., Karrenberg, D., and M. Terpstra,
"Routing Policy Specification Language (RPSL)", RFC 2622,
DOI 10.17487/RFC2622, June 1999,
<https://www.rfc-editor.org/info/rfc2622>.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002,
<https://www.rfc-editor.org/info/rfc3339>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<https://www.rfc-editor.org/info/rfc4122>.
[RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
<https://www.rfc-editor.org/info/rfc4648>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May
2015, <https://www.rfc-editor.org/info/rfc7525>.
[RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
Signature Algorithm (EdDSA)", RFC 8032,
DOI 10.17487/RFC8032, January 2017,
<https://www.rfc-editor.org/info/rfc8032>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8615] Nottingham, M., "Well-Known Uniform Resource Identifiers
(URIs)", RFC 8615, DOI 10.17487/RFC8615, May 2019,
<https://www.rfc-editor.org/info/rfc8615>.
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[SHS] National Institute of Standards and Technology, "Secure
Hash Standard", March 2012,
<http://csrc.nist.gov/publications/fips/fips180-4/fips-
180-4.pdf>.
13.2. Informative References
[RFC8182] Bruijnzeels, T., Muravskiy, O., Weber, B., and R. Austein,
"The RPKI Repository Delta Protocol (RRDP)", RFC 8182,
DOI 10.17487/RFC8182, July 2017,
<https://www.rfc-editor.org/info/rfc8182>.
Authors' Addresses
Sasha Romijn
Reliably Coded
Amsterdam
Netherlands
Email: sasha@reliablycoded.nl
Job Snijders
Fastly
Amsterdam
Netherlands
Email: job@fastly.com
Edward Shryane
RIPE NCC
Amsterdam
Netherlands
Email: eshryane@ripe.net
Stavros Konstantaras
AMS-IX
Amsterdam
Netherlands
Email: stavros.konstantaras@ams-ix.net
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