Add.In the Replace tab of a Normalization Rule's properties, you can define find-and-replace values for columns in the content of log messages normalized by the rule. To access this tab, see:
Working with Normalization Rules
Defining a Regular Expression for a Normalization Rule
If a specified column in a log message contains the Original Text value, TLC overwrites the value with the New Text value in the Normalized Message (see Table 90). To insert a value without overwriting an existing value, simply enter a null value in the Original Text column (i.e. leave the field empty).
To add a new Column, clickAdd.
To change the find-and-replace values for a Column, select and edit the Column's Original Text and/or New Text values.
To delete a Column, select the Column's row, click the arrow to the left of the row, and click
Delete.
|
Column |
Description |
|---|---|
|
Column |
The name of a column in log messages. |
|
Original Text |
The column content to be replaced. Tip: The Original Text column supports the use of simple .NET regular expressions. However, the following characters are not supported: | (OR) |
|
New Text |
The content with which the rule will overwrite the Original Text. |
Some columns require the use of integers in the New Text fields; for example, the Action column in a firewall schema. If a Column in a log message contains a hexadecimal number that you want stored as an integer in an Event-Management Database, insert "0x" in front of the column name in the New Text field. For example:
0x<dstport>
With the Convert function, you can convert the type of data in a log message (see Table 91).
|
Field Values |
Converts ... |
|---|---|
|
Original Text = Convert:<text> New Text = Base64 |
... a text value to a Base 64 value |
|
Original Text = Convert:<text> New Text = Hex |
... a text value to a hexadecimal value |
|
Original Text =Convert:<host_name> New Text = IP |
... a host name to an IP address Note: Host names cannot be saved in Event-Management Databases. If the rule's Normalized Messages will be saved as Events in a database, you should use this format to convert any host names in log-message columns. |
|
Original Text =Convert:<ip_address> New Text = Rotate |
... a rotated IP address to standard format Note: IP addresses in reverse notation cannot be saved in Event-Management Databases. If the rule's Normalized Messages will be saved as Events in a database, you should use this format to rotate any reversed IP addresses in log-message columns (for instance, changing 1.0.168.192 to 192.168.0.1). |
TLC supports a variety of formats for timestamps. To format the timestamps in Events created by a Normalization Rule, use the following variables when defining the variable's .NET regular expression (see Defining a Regular Expression for a Normalization Rule).
<year> - The year can be in either 2-digit or 4-digit format.
<month> - The month as a number or a name.
<day> - Numerical day of the month.
<time> - The time of day in 24-hour time. Format: 00:00:00.
<hour> - The numerical hour of the day in 24-hour time.
<minute> - The numerical value from 0 - 60.
<second> - A numerical value from 0 - 60.
Examples:
(?<month>[A-Za-z]+) (?<day>[\d]+) (?<year>\d+) (?<time>[0-9:]+)
(?<month>[0-9]+) (?<day>[\d]+) (?<year>\d+) (?<time>[0-9:]+)
(?<month>[0-9]+) (?<day>[\d]+) (?<year>\d+) (?<time>[0-9:]+)
(?<month>[0-9]+) (?<day>[\d]+) (?<year>\d+) (?<hour>[0-9]+):(?<minute>[0-9]+):(?<second>[0-9]+)
With the <epochtime> variable, you can convert timestamps formatted in Epoch time to standard time. For example, if a log message contains the following timestamp ...
1200820429.002: %PIX-4-106023: Deny udp src dmz:192.168.0.1/2967...
... you might insert the following content in the rule's regular expression:
(<epochtime>[0-9.]+): %PIX....