flow-xlate(1)

NAME
flow-xlate — Apply translations to selected fields of a flow.

SYNOPSIS

flow-xlate [-hkn] [-b big|little] [-C comment] [-d debug_level] [-v variable binding] [-V flow_version] [-x xlate_fname] [-X xlate_definition] [-z z_level]

DESCRIPTION

The flow-xlate utility is used to apply translations to flows. Translations are defined in a configuration file and are composed of actions and a definition to invoke action(s). The definitions are in the form of terms, each term can have a filter and multiple actions.

Words in the configuration file of the form @VAR or @{VAR:default} will be expanded at run-time by setting variable names with the -v option.

Translation actions begin with the xlate-action keyword followed by a symbolic name. Each action has a type defined below.

Translation definitions begin with the xlate-definition keyword followed by a symbolic name. Each definition is composed of terms which are evaluated in the order of the configuration file. A term may invoke a filter to conditionally invoke an action.

Action type/sub-commands                Description/Example
------------------------------------------------------------------------
ip-source-address-to-network            Zero host bits based on mask.
ip-destination-address-to-network       Zero host bits based on mask.

(no sub-commands)

ip-source-address-to-class-network      Zero source host bits to
match class.
ip-destination-address-to-class-network Zero dst host bits to
match class.

(no sub-commands)

ip-source-address-anonymize             Anonymize source address.
ip-destination-address-anonymize        Anonymize destination address.
ip-address-anonymize                    Anonymize src/dst address.

algorithm                           Algorithm.  cryptopan-aes128 is
currently supported.
algorithm cryptopan-aes128

key                                 Key.  Key is 128 bits in hex.
key 0123456789ABCDEFG

key-file                            File to load key from.  Key is
128 bits in hex.
key-file /mfstmp/secret-key

key-file-refresh                    How often to check the key file.
Interval is in minutes, the
optional second argument is
hour:min:sec to specify the
first refresh.  This example
will load a new key every day
at 12:00:00.
14400 12:00:00

ip-address-privacy-mask                 Apply a mask to the source and
destination address to remove
bits.

ip-port-privacy-mask                    Apply a mask to the source and
destination port to remove
bits.

tag-mask                                Apply mask to the source and
destination tag.

mask                                Source and Destination mask
to apply.
mask 0xFFFF 0xFFFF

scale                                   Scale packets and bytes.

scale                                 Scale to apply.
scale 100

replace-source-as0                      Replace source AS 0
replace-destination-as0                 Replace destination AS 0

as                                    AS replacement value.
as 3112

OPTIONS

-b big|little
    Byte order of output.

-C Comment
    Add a comment.

-d debug_level
    Enable debugging.

-h  Display help.

-k  Keep time from input.

-n  Don't load configuration file. Useful only with -V

-v variable binding
    Set a variable FOO=bar.

-V pdu_version
    Use pdu_version format output.

1    NetFlow version 1 (No sequence numbers, AS, or mask)
5    NetFlow version 5
6    NetFlow version 6 (5+ Encapsulation size)
7    NetFlow version 7 (Catalyst switches)
8.1  NetFlow AS Aggregation
8.2  NetFlow Proto Port Aggregation
8.3  NetFlow Source Prefix Aggregation
8.4  NetFlow Destination Prefix Aggregation
8.5  NetFlow Prefix Aggregation
8.6  NetFlow Destination (Catalyst switches)
8.7  NetFlow Source Destination (Catalyst switches)
8.8  NetFlow Full Flow (Catalyst switches)
8.9  NetFlow ToS AS Aggregation
8.10 NetFlow ToS Proto Port Aggregation
8.11 NetFlow ToS Source Prefix Aggregation
8.12 NetFlow ToS Destination Prefix Aggregation
8.13 NetFlow ToS Prefix Aggregation
8.14 NetFlow ToS Prefix Port Aggregation
1005 Flow-Tools tagged version 5

-x xlate_fname
    Translation config file name. Defaults to /var/flow-tools/cfg/xlate.cfg

-X xlate_definition
    Translation definition. Defaults to default.

-z z_level
    Configure compression level to z_level. 0 is disabled (no compression), 9 is highest compression.

EXAMPLES

Convert the version 7 flows in flows.v7 to version 5, storing the result in flows.v5.

flow-xlate -V5 < flows.v7 > flows.v5

Set the low 11 bits in the IP addresses to zero unless the address is multicast or it belongs to the 192.88.99/24 network.

# xlate.cfg
include-filter filter.cfg

xlate-action MULTICAST-PRIVACY
type ip-address-privacy-mask
mask 0xFFFFFFFF 0xFFFFFFFF

xlate-action UNICAST-PRIVACY
type ip-address-privacy-mask
mask 0xFFFFFF00 0xFFFFF800

xlate-definition abilene_privacy
term
filter mcast
action MULTICAST-PRIVACY
stop
term
filter ucast
action UNICAST-PRIVACY

# filter.cfg
filter-primitive MCAST
type ip-address-mask
permit 224.0.0.0 240.0.0.0

filter-primitive UCAST
type ip-address-mask
deny 224.0.0.0 240.0.0.0
default permit

filter-primitive SKIP
type ip-address-mask
deny 192.88.99.0 255.255.255.0
default permit

filter-definition mcast
match ip-destination-address MCAST

filter-definition ucast
match ip-destination-address UCAST
match ip-destination-address SKIP
match ip-source-address SKIP

flow-cat flows | flow-xlate -xxlate.cfg -Xabilene_privacy | flow-print

FILES

Configuration files: Symbols - /var/flow-tools/sym/*. Filter - /var/flow-tools/cfg/filter.cfg. Xlate - /var/flow-tools/cfg/xlate.cfg.

BUGS

The scale option can overflow the 32 bit flow counters. This could be solved by detecting this condition and splitting the flow in two.

Translation between aggregated and non aggregated formats is not supported.

AUTHOR

Mark Fullmer maf@splintered.net

SEE ALSO

flow-tools(1)