Snapshot function is unique to IP Accounting. The collected data can be used for performance and trending applications that require collections at regular intervals. Polling entire MIB tables across multiple network elements would introduce some inaccuracies, and hence no real Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўfrozenР В Р вЂ Р В РІР‚С™Р РЋРЎС™ snapshots. Trying to achieve the same result by synchronously

The checkpoint database offers a Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўfrozenР В Р вЂ Р В РІР‚С™Р РЋРЎС™ snapshot of the complete network. This copy request can be automated across the network to be executed at the same time, and a Network Management applicationР В РІР‚СњР вЂ™Р’В¬an later retrieve the accounting details from the checkpoint database to present consistent accounting data to the operator. To get a snapshot of the traffic statistics,Р В РІР‚СњР В РІР‚С› CLI command or SNMP request can be executed to copy the current status from the active database to the checkpoint database. The active collection process always updates the active databaseР В РІР‚СњР В РІР‚С›nd therefore constantly increments the counters while packets pass the router. The operator with the opportunity of Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўsnapshotР В Р вЂ Р В РІР‚С™Р РЋРЎС™ collections in the network, IP Accounting (Layer 3) maintains two accountingР В РІР‚СњР вЂ™Р’Вatabases: an active database and a checkpoint database. IP Accounting (LayerР В РІР‚СњР В РІвЂљВ¬) collects individual IP address details, so it can be used to identify specific users for usage-based billing. Generated by the router or traffic terminating in the router is not included in the accounting statistics. Only transit traffic that enters and leaves the router is measured, and only on an outbound basis. IP Accounting (Layer 3) collects the number of bytes and packets processed by the network element on a source and destination To the questions raised in Chapter 2, Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўData Collection MethodologyР В Р вЂ Р В РІР‚С™Р РЋРЎС™: It concludes by comparing the IP Accounting features First, the fundamentals are explained,Р В РІР‚СњР В РІР‚РЋollowed by an overview of CLI operations, and then SNMP operations. This chapter discusses in detail each flavor of IP Accounting, using a basic structure. The command-line interface (CLI) commands as titles, except for Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўIP Accounting Access Control List,Р В Р вЂ Р В РІР‚С™Р РЋРЎС™ where the related CLI command is ip accounting access-violations. Note that Cisco documentation is not always consistent for the different IP Accounting features.

IP Accounting Access Control List (ACL).

Basic IP Accounting, which this book calls Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўIP Accounting (Layer 3)Р В Р вЂ Р В РІР‚С™Р РЋРЎС™.

Refer to coverage of NetFlow Layer 2 and the Security Monitoring Exports feature in Chapter 7, Р В Р вЂ Р В РІР‚С™Р РЋРЎв„ўNetFlow.Р В Р вЂ Р В РІР‚С™Р РЋРЎС™ Note that NetFlow recently added the export of the MAC addressР В РІР‚СњР В РІР‚С›s a new information element. Furthermore, access-list accountingР В РІР‚СњР вЂ™Р’В¬urrently cannot be solved with the NetFlow implementation. However, compared to NetFlow, IP Accounting offers some advantages that make it an interestingР В РІР‚СњР В РІР‚РЋeature to investigate: easy results retrieval via a MIB and limited resource consumption. The fact that Cisco has considered replacing IP Accounting by adding new features to NetFlow potentially turns IP Accounting IP Accounting is a very useful accounting feature in Cisco IOS, but itР В Р вЂ Р В РІР‚С™Р Р†РІР‚С›РЎС›s not as well known as other features, such as NetFlow.

Cisco mac address is 00 00 00