Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

You must enable ifMIB persistence by issuing the snmp-server ifindex persistcommand. Then issue the snmp mib persist cbqoscommand to enable CBQoS MIB index persistence.

Note	If you issue the snmp mib persist cbqoscommandbeforethe snmp-server ifindex persistcommand, you receive a prompt requesting you to enable ifIndex persistence first.

If the internal hashing of configuration strings causes too many collisions, NVRAM storage may become tight. You can issue the more nvram command to display a new collision file called cbqos-mib to help you keep track of the size.

The cbQosConfigIndex, cbQosObjectsIndex, and cbQosPolicyIndex are volatile because when a networking device reboots, the index numbers may change. This happens because system rebooting can cause the order of the Modular QoS CLI (MQC) configuration to differ from the actual configuration order, which is user-driven and unpredictable. As a result, you must read the MIB frequently to extract statistical and configuration information. Therefore, once a reload has occurred, the MIB has to be repolled to reestablish the indexes to the data stored in the CBQoS MIB.

Traditionally, MIB persistence is handled by Cisco IOS APIs, which save the index and key information to NVRAM. The data is then retrieved and repopulated after reloading. However, this approach does not work well for the current implementation of the cbQosObjectsIndex because of the large amount of information that needs to be saved.

An index encoding scheme based on configuration entries instead of operational sequence is being implemented to provide persistent indexes on router reload so that MIB information retains the same set of object values each time that a networking device reboots.

The index encoding scheme has been changed to handle the performance/scalability issue. Each service policy is uniquely identified by an index called cbQosPolicyIndex, and its cbQosObjectsIndex is uniquely identified under the service policy.

Note	As a result of this change in the index encoding scheme, an application must not assume that the cbQosPolicyIndex is usually identical to its cbQosObjectsIndex as a policy-map.

These enhancements provide a repeatable method for generating MIB indexes so that they do not change between reboots.

The complexity of configuring and correlating statistics objects is reduced, making it easier for network management applications to gather accurate information.

1.    enable

2.    configure terminal

3.    snmp-server ifindex persist

4.    snmp mib persist [cbqos | v3mibs]

5.    end

6.    write mib-data

1.    enable

2.    show running-config include cbqos

3.    exit