ipfixcol2-ipfix-output(7)

Name
ipfixcol2-ipfix-output - IPFIX (output plugin)

Description

The plugin writes incoming IPFIX Messages to an IPFIX File or a series of IPFIX Files.

An IPFIX File is a serialized stream of IPFIX Messages. Simply put, the plugin stores all valid packets received by the collector into one or more IPFIX Files. Although this is not an optimal way to store flows, it can be quite useful for testing purposes - capture flow records into IPFIX File(s) and replay them using ipfixsend2 tool.

Limitations

In a situation when multiple exporters are using the same ODID at a time, the file format can store flow records only from one of the conflicting exporters with the given ODID.

This is due to fact that the IPFIX Data Records (i.e. flow records) are formatted based on so called (Options) Template definitions (i.e. descriptions of flow record structures), which are unique for combination of a Transport Session (e.g. connection to a flow exporter) and an ODID. As there is no session information in raw IPFIX Messages, we can't distinguish Messages from multiple sessions using the same ODID. For this reason, each ODID can be used only by one session at a time, and all messages from other sessions using the same ODID that's already in use are ignored and a warning message is shown. Once a Transport Session is closed, ODIDs used by the session are released and can be later reused by another session.

Example configuration

            <output>
                <name>IPFIX output</name>
                <plugin>ipfix</plugin>
                <params>
                    <filename>/tmp/ipfix/%Y%m%d%H%M%S.ipfix</filename>
                    <useLocalTime>false</useLocalTime>
                    <windowSize>300</windowSize>
                    <alignWindows>true</alignWindows>
                    <preserveOriginal>false</preserveOriginal>
                    <rotateOnExportTime>false</rotateOnExportTime>
                </params>
            </output>

Parameters

    filename
        Specifies an absolute path of output files. The path should contain format specifier for day, month, etc. For example "/tmp/ipfix/%Y%m%d%H%M%S.ipfix". See strftime(3) for more information.

    useLocalTime
        Specifies whether the time values in filenames should be in local time instead of UTC. [default: false]

    windowSize
        Specifies the time interval in seconds to rotate files. If the value is "0", all flow will be stored into a single file. [default: 0]

    alignWindows
        Align file rotation with next N minute interval. [values: true/false, default: true]

    preserveOriginal
        Preserve and store original IPFIX Messages as received by the plugin i.e. do not modify the Messages or their sequence numbers. If this option is disabled (recommended), Data Sets with unknown (Options) Templates are left out from the file and sequence numbers are adjusted accordingly (starts from 0), which should produce warning-free stream of IPFIX Messages. However, if the original IPFIX Messages are preserved, some warnings (e.g. missing (Options) Templates, unexpected sequence number, etc.) might be produced during replay and even errors might raise when there is an ODID collision and the main Transport Session is replaced. Use with caution. [values: true/false, default: false]

    rotateOnExportTime
        Specifies whether files should be rotated based on IPFIX Export Time (i.e. timestamp from IPFIX Message header) instead of system time. If enabled, the Export Time is used also for creating filenames. Warning: If the plugin receives flow records from multiple exporters at time the rotation could be unsteady. [default: false]

Note

After a new IPFIX File is created, all previously seen and still valid (Options) Templates of the each ODID are written to the file once the first IPFIX Message corresponding to the ODID arrives with at least one successfully parsed data record. This is necessary so each file can be used independently of the (Options) Template definitions from previous files.

ipfixsend2 tool doesn't support sequential reading of multiple IPFIX Files right now. However, there is a workaround - you can merge multiple IPFIX Files using cat tool e.g. cat file1.ipfix file2.ipfix > merge.ipfix and then use ipfixsend2 -i merge.ipfix to send data.

Author
Michal Sedlák (xsedla0v@stud.fit.vutbr.cz), Lukáš Huták (lukas.hutak@cesnet.cz)

Copyright
Copyright © 2019 CESNET, z.s.p.o.