http://kb.juniper.net/InfoCenter/index?page=content&id=KB4214&actp=search&viewlocale=en_US&searchid=1296236314942

Summary:
Configuring the Juniper Firewall Traffic Log (Policy Log)
Problem or Goal:

Solution:
Juniper Firewalls provide traffic logs to monitor and record the traffic that policies permit across the firewall. A traffic log notes the following elements for each session:
  • Date and time that the connection started
  • Source address and port number
  • Translated source address and port number
  • Destination address and port number
  • The duration of the session
  • The service used in the session

To log all traffic that a Juniper firewall device receives, you must enable the logging option for all policies.

To log specific traffic, enable logging only on policies that apply to that traffic.

The firewall generates logs when sessions end.  However beginning with ScreenOS 5.2.0 and above, you also have the option to start logging at session initiation.  Logging at session init will not show duration but it can be useful for troubleshooting purposes. 

Note: There are three ways to view the logs:

To configure the Juniper Firewall Traffic Log, perform the following steps:

Step one: Open the WebUI. For assistance, see KB4060 - Accessing Your NetScreen, SSG, or ISG Firewall Using the WebUI.


Step two: From the ScreenOS options menu, click Policies.

Image of step two

Step three: In the From drop-down menu, select the desired From and To zones.  For example, in the From drop-down menu, click to select Trust. In the To drop-down menu, click to select Untrust.

Image of step three and four

Step four: Click New or Edit.

Step five:  Click to select Logging.


step five

By checking the first box, the security device generates logs when sessions end. By checking the 'at Session Beginning', the security device generate logs when sessions start. If both are selected, you will get both entries.

Step six:   Click OK.

Note: You can view traffic logs stored in flash storage on the Juniper firewall device through either the CLI or WebUI. You may also open or save the file to the location you specify, and then use an ASCII text editor (such as Notepad or WordPad) to view the file. Alternatively, you can send them to an external storage space, or include traffic logs with event logs sent by email to an administrator. To view the traffic logs through the WebUI, perform the following:

Step seven:   To view the Traffic Logs from the ScreenOS options menu, click Reports, and then select Policies.  To view the Traffic Logs from the CLI, enter the command get log traffic <options>.

Purpose:
Troubleshooting
Related Links:
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