Mirroring with IRRd

IRRd can mirror other sources, and offers mirroring services for other users.

This page explains the processes and caveats involved in mirroring. For details on all configuration options, see the configuration documentation.

Note

If RPKI-aware mode is enabled, mirroring is also affected by RPKI validation. This is documented in the RPKI integration documentation.

Scheduling

All mirroring processes, except answering NRTM queries, are run in a separate thread for each source. The frequencies at which they run can be configured for each source and for importing and exporting separately, but there are default settings.

A global scheduler runs every 15 seconds, which will start mirror import and/or export processes for every source for which the import_timer or export_timer has expired. On startup, all mirror processes are started, as all their timers are considered expired.

If a previously scheduled process is still running, no new process will be run, until the current run for this source is finished and the timer expires again. This means that, for example, when mirroring a source in NRTM mode, import_timer can be safely kept low, even though the initial large full import may take some time.

Mirroring services for others (exporting)

IRRd can produce periodic exports and generate NRTM responses to support mirroring of authoritative or mirrored data by other users.

Periodic exports of the database can be produced for all sources. They consist of a full export of the text of all objects for a source, gzipped and encoded in UTF-8. If a serial is known, another file is exported with the serial number of this export. If the database is entirely empty, an error is logged and no files are exported.

NRTM responses can be generated for all sources that have keep_journal enabled, as the NRTM response is based on the journal, which records changes to objects. A journal can be kept for both authoritative sources and mirrors.

In typical setups, the files exported to export_destination will be published over FTP to allow mirrors to load all initial data. After that, NRTM requests can be made to receive recent changes. If a mirroring client lags behind too far, it may need to re-import the entire database to catch up.

The NRTM query format is:

-g <source>:<version>:<serial start>-<serial end>

The version can be 1 or 3. The serial range included the starting and ending serials. If the ending serial is LAST, all changes from the starting serial up to the most recent change will be sent. Admins can configure an access list for NRTM queries. By default all NRTM requests are denied.

To a query like -g EXAMPLESOURCE:3:998350-LAST, the response may look like this:

%START Version: 3 EXAMPLESOURCE 998350-998351

ADD 998350

person:         Test person
address:        DashCare BV
address:        Amsterdam
address:        The Netherlands
phone:          +31 20 000 0000
nic-hdl:        PERSON-TEST
mnt-by:         TEST-MNT
e-mail:         email@example.com
source:         EXAMPLESOURCE

DEL 998351

route-set:      RS-TEST
descr:          TEST route set
mbrs-by-ref:    TEST-MNT
tech-c:         PERSON-TEST
admin-c:        PERSON-TEST
mnt-by:         TEST-MNT
source:         EXAMPLESOURCE

%END EXAMPLESOURCE

In NRTM version 1, serials for individual operations (on the ADD/DEL lines are omitted, and the version in the header is 1.

Caution

NRTM version 1 can be ambiguous when there are gaps in NRTM serials. These can occur in a variety of situations. It is strongly recommended to always use NRTM version 3.

For authoritative databases in IRRd, serials are guaranteed to be sequential without any gaps. However, various scenarios can result in gaps in serials from mirrored databases.

Mirroring other databases (importing)

There are fundamentally two different modes to mirror other databases: NRTM mode and periodic full imports. Regardless of mode, all updates are performed in a single transaction. This means that, for example, when a full reload of a mirror is performed, clients will keep seeing the old objects until the import is entirely ready. Clients should never see half-finished imports.

NRTM mode

NRTM mode uses a download of a full copy of the database, followed by updating the local data using NRTM queries. This requires a downloadable full copy, the serial belonging to that copy, and NRTM access. This method is recommended, as it is efficient and allows IRRd to generate a journal, if enabled, so that others can mirror the source from this IRRd instance too.

The local IRRd journal, if enabled, may have different serials for the same changes, than the serials provided by the original source.

Updates will be retrieved every import_timer, and IRRd will automatically perform a full import the first time, and then use NRTM for updates.

Even in sources that normally use NRTM, IRRd can run a full new import of the database. This may be needed if the NRTM stream has gotten so far behind that the updates IRRd needs are no longer available. To start a full reload, use the irrd_mirror_force_reload command. For example, to force a full reload for the MIRROR-EXAMPLE source:

irrd_mirror_force_reload --config /etc/irrd.yaml MIRROR-EXAMPLE

The config parameter is optional. The reload will start the next time import_timer expires. After the reload, IRRd will resume mirroring from the NRTM stream.

Note that any instances mirroring from your instance (i.e. your IRRd is mirroring a source, a third party mirrors this from your instance), will also have to do a full reload, as the journal for NRTM queries is purged when doing a full reload.

Periodic full imports

For sources that do not offer NRTM, simply configuring a source of the data in import_source will make IRRd perform a new full import, every import_timer. Journals can not be generated, and NRTM queries by clients for this source will be rejected.

When import_serial_source, is set, a full import will only be run if the serial in that file is greater than the highest imported serial so far. The serial is checked every import_timer.

Downloads

For downloads, FTP and local files are supported. The full copy to be imported can consist of one or multiple files.

Validation and filtering

Regardless of mode, all objects received from mirrors are processed with non-strict object validation. Any objects that are rejected, are logged at the CRITICAL level, as they cause a data inconsistency between the original source and the mirror.

The mirror can be limited to certain RPSL object classes using the object_class_filter setting. Any objects encountered that are not included in this list, are immediately discarded. No logs are kept of this. They are also not kept in the local journal. If this setting is undefined, all known classes are accepted.

Manually loading data

IRRd also supports manually loading data. The primary use for this is a scenario where an external system or script generate RPSL data, and IRRd should serve that data. It can also be useful for testing.

It’s somewhat different from typical mirroring, where the authority for the data lies with a third party. For this reason, manual data loading uses stricter validation as well.

There are two ways to use manual data loading:

  • Calling the irrd_load_database command periodically. Each call will overwrite all data for a specific source, and erase existing journal entries.

  • Calling the irrd_load_database command once, and then using the irrd_update_database command to update the state of the database. This may be slower, but will generate journal entries to support offering NRTM mirroring services.

Caution

This process is intended for data sources such as produced by scripts. The validation is quite strict, as in script output, an error in script execution is a likely cause for any issues in the data. To force a reload of a regular mirror that normally uses NRTM, use the irrd_mirror_force_reload command instead. Mixing manual data loading with the regular mirroring options documented above is not recommended.

Command usage

The irrd_load_database and irrd_update_database command work as follows:

  • The command can be called, providing a name of a source and a path to the file to import. This file can not be gzipped.

  • The source must already be in the config file, with empty settings otherwise if no other settings are needed. The source does not have to be authoritative.

  • Upon encountering the first error, the process is aborted, and an error is printed to stdout. No records are made/changed in the database or in the logs, the previously existing objects will remain in the database. The exit status is 1.

  • When no errors were encountered, the provided file is considered the new and current state for the source. Log messages are written about the result of the import. The exit status is 0. Nothing is written to stdout.

  • An error means encountering an object that raises errors in non-strict object validation, an object with an unknown object class, or an object for which the source attribute is inconsistent with the –source argument. Unknown object classes that start with *xx are silently ignored, as these are harmless artefacts from certain legacy IRRd versions.

  • The object class filter configured, if any, is followed.

  • Manual object loading and other mirroring settings can not be mixed for the same source. Both commands will return an error and exit with status 2 if import_source or import_serial_source are set for the provided source.

Serial handling

The irrd_load_database command can be passed a serial to set:

  • If no serial is provided, and none has in the past, no serial is recorded. This is similar to sources that have import_source set, but not import_serial_source.

  • If no serial is provided, but a serial has been provided in a past command, or through another mirroring process, the existing serial is kept.

  • If a lower serial is provided than in a past import, the lower serial is recorded, but the existing data is still overwritten. This is not recommended.

  • The data is always reloaded from the provided file regardless of whether a serial was provided, or what the provided serial is.

Note

When other databases mirror the source being loaded, it is advisable to use incrementing serials, as they may use the CURRENTSERIAL file to determine whether to run a new import.

The irrd_update_database command automatically generates the correct serials, as required for NRTM support.

Examples

For example, to load data for source TEST with serial 10:

irrd_load_database --source TEST --serial 10 testv1.db

This command will replace all objects for source TEST with the contents of testv1.db, and delete all journal entries.

To update the database from a new file:

irrd_update_database --source TEST testv2.db

This command will update the objects for source TEST to match the contents of testv2.db. Journal entries, available over NRTM, are generated for the changes between testv1.db and testv2.db.

The --config parameter can be used to read the configuration from a different config file. Note that this script always acts on the current configuration file - not on the configuration that IRRd started with.

Caution

Each time irrd_load_database is called, all existing journal entries for the source are discarded, as they may no longer be complete. This breaks any ongoing NRTM mirroring by third parties. This only applies if loading was successful.

Performance

The irrd_update_database command is one of the slower processes in IRRd, due to the complexity of determining the changes between the data sets. It is not intended for larger data sets, e.g. those over 150.000 objects.