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Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring NetFlow Secure Event Logging (NSEL)
Information About NSEL
byte counters over the duration of the flow. These events are usually time-driven, which makes them
more in line with traditional Netflow; however, these events may also be triggered by state changes in
the flow.
Note
The flow-update event feature is available only in Version 8.4(5). It is not available in Version 9.0(1) or
later.
Each NSEL record has an event ID and an extended event ID field, which describes the flow event.
The ASA and ASASM implementations of NSEL provide the following major functions:
•
Tracks flow-create, flow-teardown, and flow-denied events, and generates appropriate NSEL data
records.
•
Defines and exports templates that describe the progression of a flow. Templates describe the format
of the data records that are exported through NetFlow. Each event has several record formats or
templates associated with it.
•
Tracks configured NSEL collectors and delivers templates and data records to these configured
NSEL collectors through NetFlow over UDP only.
•
Sends template information periodically to NSEL collectors. Collectors receive template
definitions, normally before receiving flow records.
•
Filters NSEL events based on the traffic and event type through Modular Policy Framework, then
sends records to different collectors. Traffic is matched based on the order in which classes are
configured. After a match is found, no other classes are checked. The supported event types are
flow-create, flow-denied, flow-teardown, and all. Records can be sent to different collectors. For
example, with two collectors, you can do the following:
–
Log all flow-denied events that match access list 1 to collector 1.
–
Log all flow-create events to collector 1.
–
Log all flow-teardown events to collector 2.
•
Delays the export of flow-create events.
Using NSEL and Syslog Messages
lists the syslog messages that have an equivalent NSEL event, event ID, and extended event
ID. The extended event ID provides more detail about the event (for example, which ACL—ingress or
egress—has denied a flow).
Note
Enabling NetFlow to export flow information makes the syslog messages that are listed in
redundant. In the interest of performance, we recommend that you disable redundant syslog messages,
because the same information is exported through NetFlow. You can enable or disable individual syslog
messages by following the procedure in the
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......