Manual Chapter : Configuring Local CGNAT Logging

Applies To:

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BIG-IP LTM

  • 11.5.10, 11.5.9, 11.5.8, 11.5.7, 11.5.6, 11.5.5, 11.5.4, 11.5.3, 11.5.2, 11.5.1
Manual Chapter

Configuring Local CGNAT Logging

Overview: Configuring local logging for CGNAT

You can configure the BIG-IP® system to send log messages about carrier grade network address translation (CGNAT) processes to the local Syslog database on the BIG-IP system.

Note: Enabling logging impacts BIG-IP system performance.

When configuring local logging of CGNAT processes, it is helpful to understand the objects you need to create and why:

Object to create in implementation Reason
Destination (formatted/local) Create a formatted log destination to format the logs in human-readable name/value pairs, and forward the logs to the local-syslog database.
Publisher (local-syslog) Create a log publisher to send logs to the previously created destination that formats the logs in name/value pairs, and forwards the logs to the local Syslog database on the BIG-IP system.
LSN pool Associate a large scale NAT (LSN) pool with a log publisher in order to log messages about the traffic that uses the pool.

Task summary

Creating a formatted local log destination for CGNAT

Create a formatted logging destination to specify that log messages about CGNAT processes are sent to the local Syslog database in a format that displays name/value pairs in a human-readable format.

  1. On the Main tab, click System > Logs > Configuration > Log Destinations .
    The Log Destinations screen opens.
  2. Click Create.
  3. In the Name field, type a unique, identifiable name for this destination.
  4. From the Type list, select Splunk.
  5. From the Forward To list, select local-syslog.
  6. Click Finished.

Creating a publisher to send log messages to the local Syslog database

Create a publisher to specify that the BIG-IP® system sends formatted log messages to the local Syslog database, on the BIG-IP system.
  1. On the Main tab, click System > Logs > Configuration > Log Publishers .
    The Log Publishers screen opens.
  2. Click Create.
  3. In the Name field, type a unique, identifiable name for this publisher.
  4. For the Destinations setting, select the previously created destination from the Available list, which formats the logs in the Splunk format and forwards the logs to the local Syslog database; click << to move the destination to the Selected list.
  5. Click Finished.

Configuring an LSN pool with a local Syslog log publisher

Before associating a large scale NAT (LSN) pool with a log publisher, ensure that at least one log publisher exists that sends formatted log messages to the local Syslog database on the BIG-IP® system.
Associate an LSN pool with the log publisher that the BIG-IP system uses to send formatted log messages to the local Syslog database.
  1. On the Main tab, click Carrier Grade NAT > LSN Pools .
    The LSN Pool List screen opens.
  2. Select an LSN pool from the list.
    The configuration screen for the pool opens.
    LSN pool configuration screen

    LSN pool configuration screen

  3. From the Log Publisher list, select the log publisher that sends formatted log messages to the local Syslog database on the BIG-IP system.
  4. Click Finished.

Implementation result

You now have an implementation in which the BIG-IP® system logs messages about CGNAT processes and sends the log messages to the local Syslog database on the BIG-IP system.