fort(8)

NAME
fort - RPKI validator and RTR server

SYNOPSIS
fort [--mode=server] [OPTIONS]

fort --mode=standalone [OPTIONS]

fort --init-tals --tal=PATH

fort [-h|--help|--V|--version|--usage]

DESCRIPTION
Fort is an RPKI "Relying Party" (RP). It's an artifact that validates Route Origin Attestations (ROAs) and BGPsec Router Keys, by way of a Public Key Infrastructure (PKI). ROAs are employed by routers, to verify BGP routing attestations.

The main validation input is one or more Trust Anchor Locator (TAL) files (--tal), which point to the RPKI Trust Anchors (ie. root certificates). Fort downloads all the resources governed by the trust anchors into a local cache (--local-repository), and proceeds to validate their entirety. The output of the validation is a set of trusted ROAs and Router Keys, which are printed to files (--output.roa and --output.bgpsec) and/or served to routers (--mode=server, --server.address, --server.port) through the RTR protocol (version 0 or 1).

OPTIONS

-h, --help
    Print long usage message and exit.

--usage
    Print short usage message and exit.

-V, --version
    Print program version and exit.

--init-tals
    Download the currently known core TALs into the existent local directory --tal, then exit.

    The "currently known core TALs" are

    https://rpki.afrinic.net/tal/afrinic.tal
    https://tal.apnic.net/apnic.tal
    https://www.arin.net/resources/manage/rpki/arin.tal
    https://www.lacnic.net/innovaportal/file/4983/1/lacnic.tal
    https://tal.rpki.ripe.net/ripe-ncc.tal

    Please note that ARIN requires that you accept a Relying Party Agreement before you can download their TAL: https://www.arin.net/resources/manage/rpki/rpa.pdf
--init-as0-tals
    Download the currently known AS0 TALs into the existent local directory --tal, then exit.

    The "currently known AS0 TALs" are

    https://tal.apnic.net/apnic-as0.tal
    https://www.lacnic.net/innovaportal/file/4983/1/lacnic-as0.tal

-f, --configuration-file=FILE
    Path to a JSON file from where additional configuration will be read.

    The configuration options are mostly the same as the ones presented in this manual. Each property is mapped as a member of the main JSON object, the members that contain a dot '.' must be set as objects (eg. "--server.port=8323" will be set as "{ "server": { "port": "8323" } }".

    An example configuration file can be seen in this manual at the EXAMPLES section.

    Some configuration options can't be set at the JSON configuration file: --version, --help, --version, and --configuration-file.

    Other configuration options can be configured exclusively at the JSON configuration file:

    rsync.program
        Name of the program needed to invoke an rsync file transfer. The default value is "rsync".

    rsync.arguments-recursive
        Arguments needed by rsync.program to perform a recursive rsync. The arguments are specified as a JSON string array; its default value is: [ "--recursive", "--delete", "--times", "--contimeout=20", "--timeout=15", "$REMOTE", "$LOCAL" ]

        FORT will replace "$REMOTE" with the remote URL it needs to download, and "$LOCAL" with the target local directory where the file is supposed to be dropped.

        If rsync.program set is rsync (default value), see more about its arguments and behavior at rsync(1).

    rsync.arguments-flat
        Arguments needed by rsync.program to perform a single-file rsync. The arguments are specified as a JSON string array; its default value is: [ "--times", "--contimeout=20", "--timeout=15", "--dirs", "$REMOTE", "$LOCAL" ]

        FORT will replace "$REMOTE" with the remote URL it needs to download, and "$LOCAL" with the target local directory where the file is supposed to be dropped.

        If rsync.program set is rsync (default value), see more about its arguments and behavior at rsync(1).

    incidences
        A listing of actions to be performed by validation upon encountering certain common error conditions. This configuration is a means to modify FORTs validator behavior upon encountering profile violations that, from experience, are often overlooked.

        The incidences are configured inside the member "incidences" as a JSON array of objects, each with two members "name" and "action", eg:

        "incidences": [
            {
                "name": "incid-hashalg-has-params",
                "action": "warn"
            }, {
                "name": "incid-obj-not-der-encoded",
                "action": "error"
            }
        ]

        An incidence contains a name and an action. The name is merely an identifier defined by FORT that states a particular error condition, and the action is an enumeration that states the outcome of a violation of the corresponding incidence.

        The action can have one of three values:
            error: Print error message in error log level, fail validation of the offending object (and all of its children).
            warn: Print error message in warning log level, continue validation as if nothing happened.
            ignore: Do not print error message, continue validation as if nothing happened.

        Currently these are the registered incidences, each with a distinct action configured by default.
            incid-hashalg-has-params (Signed Object's hash algorithm has NULL object as parameters). [Default action: ignore]
            incid-obj-not-der-encoded (Object isn't DER encoded). [Default action: ignore]
            incid-file-at-mft-not-found (File listed at manifest doesn't exist). [Default action: error]
            incid-file-at-mft-hash-not-match (File hash listed at manifest doesn't match the actual file hash). [Default action: error]
            incid-mft-stale (Manifest is stale). [Default action: error]
            incid-crl-stale (CRL is stale). [Default action: error]

        More information about incidences can be consulted at FORT's web docs.

-t, --tal=(FILE|DIRECTORY)
    Path to a .tal, or a directory containing .tal files. Fort will validate the trees pointed by them.

    The TAL ("Trust Anchor Locator") is a text file that lists a few URLs which can be used to access the "Trust Anchor" (the root of a particular RPKI tree) and its public key. (See RFC 8630.)

-r, --local-repository=DIRECTORY
    Path to a directory where the local cache of the repository will be stored and/or read.

    FORT accesses RPKI repositories either with rsync or RRDP (see RFC 8182). During each validation cycle, and depending on the preferred access methods defined by the CAs, Fort can do two things:
        - Literally invoke an rsync command (see rsync.program and rsync.arguments-recursive), which will download the files into --local-repository.
        - Fetch the RRDP Update Notification file (which implies an HTTP request) and fetch the files from there on (can be obtained from a Snapshot file or Delta files). The files will be downloaed into --local-repository.

    Fort's entire validation process operates on the resulting copy of the files (doesn't matter if the files where fetched by rsync of https).

    Because rsync uses delta encoding, you’re advised to keep this cache around. It significantly speeds up subsequent validation cycles.

    By default, the path is /tmp/fort/repository.

--daemon
    If this flag is activated, Fort will run as a daemon. The process is detached from the calling terminal and sent to the background.

    All the enabled logs will be sent to syslog, so the configured values of --log.output and --validation-log.output will be ignored.

--sync-strategy=(off|strict|root|root-except-ta)
    This argument will be DEPRECATED. Use --rsync.strategy or --rsync.enabled (if rsync is meant to be disabled) instead.

    rsync download strategy; states the way rsync URLs are approached during downloads.

    Despite this argument will be deprecated, it still can be utilized. It can have one of four values:
        - off: will disable rsync execution. So, using --sync-strategy=off will be the same as --rsync.enabled=false.
        - strict: will be the same as --rsync.strategy=strict.
        - root: will be the same as --rsync.strategy=root.
        - root-except-ta (default value): will be the same as --rsync.strategy=root-except-ta.

--work-offline
    If this flag is activated, Fort will disable all outgoing requests (currently done with: rsync and https (RRDP protocol uses HTTPS to fetch data)). All repository files (certificates, ROAs, etc.) are expected to exist at configured --local-repository.

    Otherwise, Fort will perform outgoing requests whenever this is needed. If a specific protocol needs to be deactivated, use --rsync.enabled or --http.enabled.

--shuffle-uris
    If enabled, FORT will access TAL URLs in random order. This is meant for load balancing. If disabled, FORT will access TAL URLs in sequential order.

    By default, the flag is disabled.

    This flag is only relevant if the TAL lists more than one URL. Regardless of this flag, FORT will stop iterating through the URLs as soon as it finds one that yields a successful traversal.

    If the TAL lists more than one URL, the shuffle is done honoring the priority of the protocols (see --rsync.priority and --http.priority). i.e. if the HTTP protocol has a higher priority than RSYNC, then all the shuffled HTTP URLs will come first.

--maximum-certificate-depth=UNSIGNED_INTEGER
    Maximum allowable certificate chain length. Meant to protect FORT from iterating infinitely due to certificate chain loops.

    By default, it has a value of 32. The minimum allowed value is 5.

    (Required to prevent loops and "other degenerate forms of the logical RPKI hierarchy." (RFC 6481))

--slurm=(FILE|DIRECTORY)
    Path to the SLURM FILE or SLURMs DIRECTORY.

    The SLURM definition is from RFC 8416. SLURM stands for "Simplified Local Internet Number Resource Management with the RPKI", basically is a document that can override (either as a filter or adding assertions) the global RPKI repository data fetched by FORT; potentially useful for network operators.

    In case a DIRECTORY is set, the files with extension '.slurm' will be the ones considered as SLURM files and FORT will use them.

    The configured SLURM path (either FILE or DIRECTORY) will be read each time a new validation cycle begins. If there's a syntax or content error, the last valid version of the SLURM will be applied (if there's one) and a message will be logged to indicate this action. Note that all this will happen only if --mode=server and --slurm is configured.

    A basic example of a SLURM file can be seen in this manual at the EXAMPLES section (it's almost the same as the one in RFC 8416).

    See more about SLURM configuration at FORT's web docs.

--mode=(server|standalone)
    Commands the way FORT executes the validation, its possible values are:

    server
        Enable the RTR server using the server.* arguments.

    standalone
        Disable the RTR server, the configuration options server.* are ignored and FORT performs an in-place standalone validation.

    By default, the mode is server.

--server.address=NODE(S)
    List of hostnames or numeric host addresses the RTR server will be bound to. Must resolve to (or be) bindable IP addresses. IPv4 and IPv6 are supported.

    The list of addresses must be comma sepparated, and each address must have the following format: <address>[#<port>]. Note that the port is optional; in case that a port isn't specified, the value of --server.port will be utilized with the corresponding address.

    Here are some examples of valid values for this argument:
    - --server.address="localhost": will bind to 'localhost' and the configured port at --server.port.
    - --server.address="localhost,::1#8324": same as the previous example, and also will bind to IPv6 address '::1' at the port '8324'.
    - --server.address="localhost#8323,::1#8324": will bind to 'localhost' at port '8323', and to '::1' port '8324'. The value of --server.port isn't utilized.

    If this field is omitted, FORT will attempt to bind the server using the IP address INADDR_ANY (for an IPv4 address) or IN6ADDR_ANY_INIT (for an IPv6 address). See getaddrinfo(3).

--server.port=SERVICE
    TCP port or service the server address(es) will be bound to by default if no port is set (see --server.address).

    This is a string because a service alias can be used as a valid value. The alias are commonly located at /etc/services. See also getaddrinfo(3) and services(5).

    The default port (323) is privileged. To improve security, either change or jail it.

    In case you don't wish to use another port nor execute FORT validator as root, you could use CAP_NET_BIND_SERVICE capability (to bind to privileged ports), or NAT/firewall port redirection.

--server.backlog=UNSIGNED_INTEGER
    RTR server’s listen queue length. It’s the second argument of the function listen (see more at man listen(2)). This provides a hint to the implementation which the implementation shall use to limit the number of outstanding connections in the socket’s listen queue.

    By default, it has a value of SOMAXCONN.

--server.interval.validation=UNSIGNED_INTEGER
    Number of seconds that FORT will sleep between validation cycles. The timer starts counting every time a validation is finished, not every time it begins. Therefore, the actual validation loop is longer than this number.

    By default, it has a value of 3600.

--server.interval.refresh=UNSIGNED_INTEGER
    Number of seconds that a router should wait before the next attempt to poll FORT using either a Serial Query PDU or Reset Query PDU. Countdown for this timer starts upon receipt of an End Of Data PDU (this should be administered by the client).

    This value is utilized only on RTR version 1 sessions (more information at RFC 8210 section 6).

    By default, it has a value of 3600. Minimum allowed value: 1, maximum allowed value 86400.

--server.interval.retry=UNSIGNED_INTEGER
    Number of seconds that a router should wait before retrying a failed Serial Query PDU or Reset Query PDU. Countdown for this timer starts upon failure of the query and restarts after each subsequent failure until a query succeeds (this should be administered by the client).

    This value is utilized only on RTR version 1 sessions (more information at RFC 8210 section 6).

    By default, it has a value of 600. Minimum allowed value: 1, maximum allowed value 7200.

--server.interval.expire=UNSIGNED_INTEGER
    Number of seconds that a router can retain the current version of data while unable to perform a successful subsequent query. Countdown for this timer starts upon receipt of an End Of Data PDU (this should be administered by the client).

    This value is utilized only on RTR version 1 sessions (more information at RFC 8210 section 6).

    By default, it has a value of 7200. Minimum allowed value: 600, maximum allowed value 172800. It must be larger than server.interval.refresh and server.interval.retry.

--server.deltas.lifetime=UNSIGNED_INTEGER
    When routers first connect to Fort, they request a snapshot of the validation results. (ROAs and Router Keys.) Because they need to keep their validated objects updated, and snapshots tend to be relatively large amounts of information, they request deltas afterwards over configurable intervals. ("Deltas" being the differences between snapshots.)

    During each validation cycle, Fort generates a new snapshot, as well as the deltas needed to build the new snapshot from the previous one. These are all stored in RAM. --server.deltas.lifetime is the number of iterations a set of deltas will be kept before being deallocated. (Recall that every iteration lasts --server.interval.validation seconds, plus however long the validation takes.)

    If a router lags behind, to the point Fort has already deleted the deltas it needs to update the router’s snapshot, Fort will have to fall back to fetch the entire latest snapshot instead.

--log.enabled=true|false
    Enables the operation logs.

    By default, it has a value of true (these logs are enabled).

    Read more about logs at FORT validator's web docs, module 'Logging'.

--log.level=(error|warning|info|debug)
    Defines which operation log messages will be logged according to its priority, e.g. a value of info will log messages of equal or higher level (info, warning, and error).

    The priority levels, from higher to lowest, are:
        - error
        - warning
        - info
        - debug

    By default, it has a value of warning.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--log.output=(syslog|console)
    Desired output where the operation logs will be printed.

    The value console will log messages at standard output and standard error; syslog will log to syslog.

    Depending on the OS, distinct implementations of syslog could be installed (syslog, rsyslog, or syslog-ng are the most common ones). Syslog usage and configuration is out of this man scope.

    By default, it has a value of console.

    Read more about logs at FORT validator's web docs, module 'Logging'.

-c, --log.color-output=true|false
    If enabled, the operation logs output will contain ANSI color codes. Meant for human consumption.

    Meaningful only if --log.output value is console.

    By default, it has a value of false (it's disabled).

    Read more about logs at FORT validator's web docs, module 'Logging'.

--log.file-name-format=(global-url | local-path | file-name)
    Decides which version of file names should be printed during most debug/error messages at the operation logs.

    Suppose a certificate was downloaded from `rsync://rpki.example.com/foo/bar/baz.cer` into the local cache `repository/`:

    global-url
        Will print the certificate's name as `rsync://rpki.example.com/foo/bar/baz.cer`.

    local-path
        Will print the certificate's name as `repository/rpki.example.com/foo/bar/baz.cer`.

    file-name
        Will print the certificate's name as `baz.cer`.

    By default, it has a value of global-url.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--log.facility=(auth | authpriv | cron | daemon | ftp | lpr | mail | news | user | uucp | from local0 to local7)
    Syslog facility utilized for operation logs (meaningful only if --log.output is syslog).

    By default, it has a value of daemon.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--log.tag=STRING
    Text tag that will be added to the operation log messages (it will appear inside square brackets).

    By default, it has a NULL value.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.enabled=true|false
    Enables the validation logs.

    By default, it has a value of false (these logs are disabled).

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.level=(error|warning|info|debug)
    Defines which validation log messages will be logged according to its priority, e.g. a value of info will log messages of equal or higher level (info, warning, and error).

    The priority levels, from higher to lowest, are:
        - error
        - warning
        - info
        - debug

    By default, it has a value of warning.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.output=(syslog|console)
    Desired output where the validation logs will be printed.

    The value console will log messages at standard output and standard error; syslog will log to syslog.

    Depending on the OS, distinct implementations of syslog could be installed (syslog, rsyslog, or syslog-ng are the most common ones). Syslog usage and configuration is out of this man scope.

    By default, it has a value of console.

    Read more about logs at FORT validator's web docs, module 'Logging'.

-c, --validation-log.color-output=true|false
    If enabled, the validation logs output will contain ANSI color codes. Meant for human consumption.

    Meaningful only if --validation-log.output value is console.

    By default, it has a value of false (it's disabled).

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.file-name-format=(global-url | local-path | file-name)
    Decides which version of file names should be printed during most debug/error messages at the validation logs.

    Suppose a certificate was downloaded from `rsync://rpki.example.com/foo/bar/baz.cer` into the local cache `repository/`:

    global-url
        Will print the certificate's name as `rsync://rpki.example.com/foo/bar/baz.cer`.

    local-path
        Will print the certificate's name as `repository/rpki.example.com/foo/bar/baz.cer`.

    file-name
        Will print the certificate's name as `baz.cer`.

    By default, it has a value of global-url.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.facility=(auth | authpriv | cron | daemon | ftp | lpr | mail | news | user | uucp | from local0 to local7)
    Syslog facility utilized for validation logs (meaningful only if --validation-log.output is syslog).

    By default, it has a value of daemon.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--validation-log.tag=STRING
    Text tag that will be added to the validation log messages (it will appear inside square brackets).

    By default, it has the value Validation.

    Read more about logs at FORT validator's web docs, module 'Logging'.

--http.enabled=true|false
    Enables outgoing HTTP requests.

    If disabled (eg. --http.enabled=false), FORT validator won't request HTTP URIs, and will expect to find all the corresponding repository files at --local-repository.

--http.priority=UNSIGNED_INTEGER
    Assign priority to use HTTP to fetch repository files. A higher value means a higher priority.

    This argument works along with --rsync.priority, since the higher value of the two arguments will result in the first protocol to utilize when fetching repositories files. Of course, this depends also on certificates information or the TAL URIs, since currently HTTP URIs are optional and not every RIR repository makes use of them.

    Whenever a certificate or a TAL has both RSYNC and HTTP URIs, the following criteria is followed to prioritize which one to use first:
        - --rsync.priority equals --http.priority: use the order specified at the certificate or the TAL to fetch the corresponding URI.
        - --rsync.priority greater than --http.priority: use RSYNC repository/TAL URI first; if there's an error fetching data, fallback to fetch HTTP repository/TAL URI.
        - --rsync.priority less than --http.priority: use HTTP repository/TAL URI first; if there's an error fetching data, fallback to use RSYNC repository/TAL URI.

    By default, the value is 60, so HTTP requests are preferred over rsync requests.

--http.retry.count=UNSIGNED_INTEGER
    Maximum number of retries whenever there's an error requesting an HTTP URI.

    A value of 0 means no retries.

    Whenever is necessary to request an HTTP URI, the validator will try the request at least once. If there was an error requesting the URI, the validator will retry at most --http.retry.count times to fetch the file, waiting --http.retry.interval seconds between each retry.

    By default, the value is 2.

--http.retry.interval=UNSIGNED_INTEGER
    Period (in seconds) to wait between retries after an error ocurred requestin HTTP URIs.

    By default, the value is 5.

--http.user-agent=STRING
    User-Agent to use at HTTP requests.

    The value specified (either by the argument or the default value) is utilized in libcurl’s option CURLOPT_USERAGENT.

    By default, the value is fort/<current-version>.

--http.connect-timeout=UNSIGNED_INTEGER
    Timeout (in seconds) for the connect phase.

    Whenever an HTTP connection will try to be established, the validator will wait a maximum of http.connect-timeout seconds for the peer to respond to the connection request; if the timeout is reached, the connection attempt will be ceased.

    The value specified (either by the argument or the default value) is utilized in libcurl’s option CURLOPT_CONNECTTIMEOUT.

    By default, it has a value of 30. The minimum allowed value is 1.

--http.transfer-timeout=UNSIGNED_INTEGER
    Maximum time in seconds (once the connection is established) that the request can last.

    Once the connection is established with the server, the request will last a maximum of http.transfer-timeout seconds. A value of 0 means unlimited time (default value).

    The value specified (either by the argument or the default value) is utilized in libcurl’s option CURLOPT_TIMEOUT.

    By default, it has a value of 0.

--low-speed-limit=UNSIGNED_INTEGER
    The value Fort employs as CURLOPT_LOW_SPEED_LIMIT during every HTTP transfer.

    "Abort connection if slower than LIMIT bytes/sec during TIME seconds."

    (See --low-speed-time.)

    Default: 100000 (100 KB/s)

--low-speed-time=UNSIGNED_INTEGER
    The value Fort employs as CURLOPT_LOW_SPEED_TIME during every HTTP transfer.

    "Abort connection if slower than LIMIT bytes/sec during TIME seconds."

    (See --low-speed-limit.)

    Default: 10

--http.max-file-size=UNSIGNED_INTEGER
    Maximum amount of bytes files are allowed to length during HTTP transfers.

    Default: 1000000000 (1 GB)

--http.ca-path=DIRECTORY
    Local path where the CA’s utilized to verify the peers are located.

    Useful when the CA from the peer isn’t located at the default OS certificate bundle. If specified, the peer certificate will be verified using the CAs at the path. The directory MUST be prepared using the rehash utility from the SSL library:
        - OpenSSL command (with help): $ openssl rehash -h
        - LibreSSL command (with help): $ openssl certhash -h

    The value specified is utilized in libcurl’s option CURLOPT_CAPATH.

    By default, the path has a NULL value.

--rrdp.enabled=true|false
    This argument will be DEPRECATED. Use --http.enabled instead.

--rrdp.priority=UNSIGNED_INTEGER
    This argument will be DEPRECATED. Use --http.priority instead.

--rrdp.retry.count=UNSIGNED_INTEGER
    This argument will be DEPRECATED. Use --http.retry.count instead.

--rrdp.retry.interval=UNSIGNED_INTEGER
    This argument will be DEPRECATED. Use --http.retry.interval instead.

--rsync.enabled=true|false
    Enables RSYNC requests.

    If disabled (eg. --rsync.enabled=false), FORT validator won't download files nor directories via RSYNC, and will expect to find all repository files at --local-repository.

--rsync.priority=UNSIGNED_INTEGER
    Assign priority to use RSYNC to fetch repository files. A higher value means a higher priority.

    This argument works along with --http.priority, since the higher value of the two arguments will result in the first protocol to utilize when fetching repositories files. Of course, this depends also on certificates information or the TAL URIs, since currently HTTP URIs are optional and not every RIR repository makes use of them.

    Whenever a certificate has both RSYNC and HTTP URIs, the following criteria is followed to prioritize which one to use first:
        - --rsync.priority equals --http.priority: use the order specified at the certificate or the TAL to fetch the corresponding URI.
        - --rsync.priority greater than --http.priority: use RSYNC repository/TAL URI first; if there's an error fetching data, fallback to use fetch HTTP repository/TAL URI.
        - --rsync.priority less than --http.priority: use HTTP repository/TAL URI first; if there's an error fetching data, fallback to use RSYNC repository/TAL URI.

    By default, the value is 50, so HTTP requests are preferred over rsync requests.

--rsync.strategy=(strict|root|root-except-ta)
    rsync download strategy; states the way rsync URLs are approached during downloads. It can have one of three values: strict, root, root-except-ta(default value).

    strict
        In order to enable this strategy, FORT must be compiled using the flag: ENABLE_STRICT_STRATEGY. e.g. $ make FORT_FLAGS='-DENABLE_STRICT_STRATEGY'

        RSYNC every repository publication point separately. Only skip publication points that have already been downloaded during the current validation cycle. (Assuming each synchronization is recursive.)

        For example, suppose the validator gets certificates whose caRepository access methods (in their Subject Information Access extensions) point to the following publication points:

        1. rsync://rpki.example.com/foo/bar/
        2. rsync://rpki.example.com/foo/qux/
        3. rsync://rpki.example.com/foo/bar/
        4. rsync://rpki.example.com/foo/corge/grault/
        5. rsync://rpki.example.com/foo/corge/
        6. rsync://rpki.example.com/foo/corge/waldo/

        A validator following the `strict` strategy would download `bar`, download `qux`, skip `bar`, download `corge/grault`, download `corge` and skip `corge/waldo`.

        This is the slowest, but also the strictly correct sync strategy.

    root
        For each publication point found, guess the root of its repository and RSYNC that instead. Then skip any subsequent children of said root.

        (To guess the root of a repository, the validator counts four slashes, and prunes the rest of the URL.)

        Reusing the caRepository URLs from the `strict` strategy (above) as example, a validator following the `root` strategy would download `rsync://rpki.example.com/foo`, and then skip everything else.

        Assuming that the repository is specifically structured to be found within as few roots as possible, and they contain minimal RPKI-unrelated noise files, this is the fastest synchronization strategy. At time of writing, this is true for all the current official repositories.

    root-except-ta
        Synchronizes the root certificate (the one pointed by the TAL) in 'strict' mode, and once it's validated, synchronizes the rest of the repository in 'root' mode.

        Useful if you want 'root', but the root certificate is separated from the rest of the repository. Also useful if you don't want the validator to download the entire repository without first confirming the integrity and legitimacy of the root certificate.

--rsync.retry.count=UNSIGNED_INTEGER
    Maximum number of retries whenever there's an error executing RSYNC.

    A value of 0 means no retries.

    Whenever is necessary to execute an RSYNC, the validator will try the execution at least once. If there was an error executing the RSYNC, the validator will retry it at most --rsync.retry.count times, waiting --rsync.retry.interval seconds between each retry.

    By default, the value is 2.

--rsync.retry.interval=UNSIGNED_INTEGER
    Period (in seconds) to wait between retries after an RSYNC error ocurred.

    By default, the value is 5.

--output.roa=FILE
    File where the ROAs will be printed in the configured format (see --output.format).

    When the FILE is specified, its content will be overwritten by the resulting ROAs of the validation (if FILE doesn't exists, it'll be created).

    When --output.format=csv (which is the default value), then each line of the result is printed in the following order: AS, Prefix, Max prefix length; the first line contains those column descriptors.

    When --output.format=json, then each element is printed inside an object array of "roas"; ie:
    {
      "roas": [
        {
          "asn": "AS64496",
          "prefix": "198.51.100.0/24",
          "maxLength": 24
        },
        {
          "asn": "AS64496",
          "prefix": "2001:DB8::/32",
          "maxLength": 48
        }
      ]
    }

    In order to print the ROAs at console, use a hyphen as the FILE value, eg. --output.roa=-

    By default, it has no value set.

--output.bgpsec=FILE
    File where the BGPsec Router Keys will be printed in the configured format (see --output.format).

    Since most of the data is binary (Subject Key Identifier and Subject Public Key Info), such data is base64url encoded without trailing pads.

    When the FILE is specified, its content will be overwritten by the resulting Router Keys of the validation (if FILE doesn't exists, it'll be created).

    When --output.format=csv (which is the default value), then each line of the result is printed in the following order: AS, Subject Key Identifier, Subject Public Key Info; the first line contains those column descriptors.

    When --output.format=json, then each element is printed inside an object array of "router-keys"; ie:
    {
      "router-keys": [
        {
          "asn": "AS64496",
          "ski": "<Base64 Encoded SKI>",
          "spki": "<Base64 Encoded SPKI>"
        },
        {
          "asn": "AS64496",
          "ski": "<Base64 Encoded SKI>",
          "spki": "<Base64 Encoded SPKI>"
        }
      ]
    }

    In order to print the Router Keys at console, use a hyphen as the FILE value, eg. --output.bgpsec=-

    By default, it has no value set.

--output.format=csv|json
    Output format for --output.roa and --output.bgpsec.

    By default, it has a value of csv.

--thread-pool.server.max=UNSIGNED_INTEGER
    Number of threads the RTR server will reserve for RTR client (router) request handling. The server will be able to handle --thread-pool.server.max requests at most, at once. Additional requests will queue.

    Minimum: 1
    Maximum: UINT_MAX
    Default: 20
--thread-pool.validation.max=UNSIGNED_INTEGER
    Maximum number of threads that will be spawned at an internal thread pool in order to run validation cycles.

    When a validation cycle begins, one thread per configured TAL is utilized; once the whole RPKI tree of the TAL is validated, the thread is returned to the pool.

    If there are more TALs at --tal than --thread-pool.validation.max threads at the pool, is very likely that the validation cycles take a bit more of time to complete since only --thread-pool.validation.max threads will be working at the same time. E.g. if --thread-pool.validation.max=2 and the location at --tal has 4 TAL files, only 2 TALs will be validated simultaneously while the rest waits in a queue until there's an available thread at the pool to attend them.

    By default, it has a value of 5. Minimum allowed value: 1, maximum allowed value 100.
--asn1-decode-max-stack=UNSIGNED_INTEGER
    ASN1 decoder max allowed stack size in bytes, utilized to avoid a stack overflow when a large nested ASN1 object is parsed.

    By default, it has a value of 4096 (4 kB).

--stale-repository-period=UNSIGNED_INTEGER
    Time period that must lapse to warn about a stale repository (the messages will be sent to the operation log). The time lapse starts once the repository download has been retried (see --rsync.retry.count and --http.retry.count) and failed after such retries.

    A repository is considered stale if its files can't be fetched due to a communication error and this error persists across validation cycles. This kind of issues can be due to a local misconfiguration (eg. a firewall that blocks incoming data) or a problem at the server (eg. the server is down).

    Despite who's "fault" is, FORT validator will try to work with the local files from --local-repository.

    The communication errors sent to the operation log, are those related to "first level" RPKI servers; commonly this are the servers maintained by the RIRs.

    Currently all the communication errors are logged at the validation log. This argument (--stale-repository-period) is merely to send this error messages also to the operation log.

    A value equal to 0 means that the communication errors will be logged at once.

    By default, it has a value of 43200 (12 hours).

EXAMPLES
fort --init-tals --tal=/tmp/tal
    Download the 5 RIR TALs into the specified directory. ARIN TAL will be downloaded only if the user accepts ARIN's RPA.

fort -t /tmp/tal -r /tmp/repository --server.port=9323
    Run FORT with all the default values, using a custom TALs directory, a custom repository directory as well, and binding the RTR server to port 9323.

fort -t /tmp/tal -r /tmp/repository --mode=standalone --output.roa=-
    Run FORT as standalone and output ROAs CSV to the console.

fort -t /tmp/tal -r /tmp/repository \
     --mode=standalone \
     --slurm=/tmp/myslurm.slurm
    Run FORT as standalone and using a SLURM file.

fort --configuration-file=conf.json
    Run FORT using the JSON configuration file conf.json.

fort -t /tmp/tal -r /tmp/repository \
     --server.address=::1 --server.port=9323 \
     --server.interval.validation=1800 \
     --output.roa=/tmp/roas.csv
    Run FORT with RTR server listening on IPv6 address ::1, port 9323, validating every 30 minutes, and printing the ROAs CSV in a file.

Complete configuration file
    This is an example of a valid JSON configuration file with all its members set to a specific value:
    {
      "tal": "/tmp/fort/tal/",
      "local-repository": "/tmp/fort/repository/",
      "work-offline": false,
      "shuffle-uris": true,
      "maximum-certificate-depth": 32,
      "mode": "server",
      "daemon": false,
      "slurm": "/tmp/fort/test.slurm",
      "server": {
        "address": [
          "192.0.2.1",
          "2001:db8::1"
        ],
        "port": "8323",
        "backlog": 64,
        "interval": {
          "validation": 3600,
          "refresh": 3600,
          "retry": 600,
          "expire": 7200
        },
        "deltas": {
          "lifetime": 4
        }
      },
      "log": {
        "enabled": true,
        "level": "warning",
        "output": "console",
        "color-output": true,
        "file-name-format": "local-path",
        "facility": "daemon",
        "tag": "Operation"
      },
      "validation-log": {
        "enabled": false,
        "level": "warning",
        "output": "console",
        "color-output": true,
        "file-name-format": "local-path",
        "facility": "daemon",
        "tag": "Validation"
      },
      "http": {
        "enabled": true,
        "priority": 60,
        "retry": {
          "count": 2,
          "interval": 5
        },
        "user-agent": "fort/1.5.1",
        "connect-timeout": 30,
        "transfer-timeout": 0,
        "idle-timeout": 15,
        "ca-path": "/usr/local/ssl/certs"
      },
      "rsync": {
        "enabled": true,
        "priority": 50,
        "strategy": "root-except-ta",
        "retry": {
          "count": 2,
          "interval": 5
        },
        "program": "rsync",
        "arguments-recursive": [
          "--recursive",
          "--delete",
          "--times",
          "--contimeout=20",
          "--timeout=15",
          "$REMOTE",
          "$LOCAL"
        ],
        "arguments-flat": [
          "--times",
          "--contimeout=20",
          "--timeout=15",
          "--dirs",
          "$REMOTE",
          "$LOCAL"
        ]
      },
      "incidences": [
        {
          "name": "incid-hashalg-has-params",
          "action": "ignore"
        },
        {
          "name": "incid-obj-not-der-encoded",
          "action": "ignore"
        },
        {
          "name": "incid-file-at-mft-not-found",
          "action": "error"
        },
        {
          "name": "incid-file-at-mft-hash-not-match",
          "action": "error"
        },
        {
          "name": "incid-mft-stale",
          "action": "error"
        },
        {
          "name": "incid-crl-stale",
          "action": "error"
        }
      ],
      "output": {
        "roa": "/tmp/fort/roas.csv",
        "bgpsec": "/tmp/fort/bgpsec.csv",
        "format": "csv"
      },
      "thread-pool": {
        "server": {
          "max": 20
        },
        "validation": {
          "max": 5
        }
      },
      "asn1-decode-max-stack": 4096,
      "stale-repository-period": 43200
    }

Dummy SLURM file
    This is an example of a SLURM file with some prefix filters and assertions, as well as some dummy Router Keys (BGPsec) info:
    {
      "slurmVersion": 1,
      "validationOutputFilters": {
        "prefixFilters": [
          {
            "prefix": "192.0.2.0/24",
            "comment": "All VRPs encompassed by prefix"
          },
          {
            "asn": 64496,
            "comment": "All VRPs matching ASN"
          },
          {
            "prefix": "198.51.100.0/24",
            "asn": 64497,
            "comment": "All VRPs encompassed by prefix, matching ASN"
          }
        ],
        "bgpsecFilters": [
          {
            "asn": 64496,
            "comment": "All keys for ASN"
          },
          {
            "SKI": "Q8KMeBsCto1PJ6EuhowleIGNL7A",
            "comment": "Key matching Router SKI"
          },
          {
            "asn": 64497,
            "SKI": "g5RQYCnkMpDqEbt9WazTeB19nZs",
            "comment": "Key for ASN 64497 matching Router SKI"
          }
        ]
      },
      "locallyAddedAssertions": {
        "prefixAssertions": [
          {
            "asn": 64496,
            "prefix": "198.51.100.0/24",
            "comment": "My other important route"
          },
          {
            "asn": 64496,
            "prefix": "2001:DB8::/32",
            "maxPrefixLength": 48,
            "comment": "My other important de-aggregated routes"
          }
        ],
        "bgpsecAssertions": [
          {
            "asn": 64496,
            "SKI": "Dulqji-sUM5sX5M-3mqngKaFDjE",
            "routerPublicKey": "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE-rkSLXlPpL_m-L7CfCfKrv1FHrM55FsIc8fMlnjHE6Y5nTuCn3UgWfCV6sYuGUZzPZ0Ey6AvezmfcELUB87eBA"
          }
        ]
      }
    }

SEE ALSO
Regular man pages
    getaddrinfo(3), services(5), listen(2), rsync(1)

FORTs official documentation
    More documentation about FORT validator can be consulted at github repository (https://github.com/NICMx/FORT-validator) and github website (https://nicmx.github.io/FORT-validator/)