Published On: August 6ᵗʰ, 2019 02:00

QoS: NBAR Configuration Guide, Cisco IOS XE Release 3S

The NBAR2 Protocol Pack Hitless Upgrade feature enables users to seamlessly upgrade a Network-Based Application Recognition (NBAR) protocol pack or change the NBAR configurations without impacting any of the current classification configurations on a device.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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.

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.

Restrictions for NBAR2 Protocol Pack Hitless Upgrade

Additional memory is required to support the NBAR2 Protocol Pack Hitless Upgrade feature because it holds together two configurations until the previous configuration is aged.

Information About NBAR2 Protocol Pack Hitless Upgrade

Overview of NBAR2 PP Hitless Upgrade

Hitless Upgrade is the method to upgrade the NBAR2 Protocol Pack (PP) components on an NBAR engine without incurring any service downtime. In earlier Cisco IOS software releases, NBAR could hold only a single configuration graph on the control plane client that is transferred to the data path. From Cisco IOS XE Release 3.12S onward, NBAR can hold several configurations graphs at a single time. When a new configuration change occurs, a new configuration graph is created on the control plane client. The new graph is downloaded to the data plane, and all new flows are directed to the new graph.

If a packet arrives from a flow that was being classified, the packet is directed to the correct configuration graph (the one that was active when the flow was created).

The following illustration displays the NBAR system state after a configuration or protocol pack update:

Figure 1. Aging a Graph

In the illustration above, when a new graph is created, the old graph is moved to the aging state. In an aged state, only flows that are associated with the graph are referenced with the graph. If a flow is not classified until aging time, it is reported as unknown by NBAR.


Note


Due to memory limitations, it is important to limit the number of parallel existing graphs and aging graphs in the NBAR system. Currently, all platforms can hold a maximum two configurations at a given time.

Use the show platform software nbar statistics command to view the status of NBAR.

Benefits of NBAR2 Protocol Pack Hitless Upgrade

NBAR2 Protocol Pack Hitless Upgrade provides the following benefits:
  • No loss of information for classified flows during a protocol upgrade
  • No impact on new flows
  • No impact on in-progress flows

Additional References for NBAR2 Protocol Pack Hitless Upgrade

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

NBAR Protocol Pack

QoS: NBAR Configuration Guide

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Feature Information for NBAR2 Protocol Pack Hitless Upgrade

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

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.
Table 1 Feature Information for NBAR2 Protocol Pack Hitless Upgrade

Feature Name

Releases

Feature Information

NBAR2 Protocol Pack Hitless Upgrade

Cisco IOS XE Release 3.12S

The NBAR2 Protocol Pack Hitless Upgrade feature enables seamless upgrade of a NBAR protocol pack or NBAR configurations without impacting any of the current classification configurations on a device.

In Cisco IOS XE Release 3.12S, support was added for the Cisco ASR 1000 Series Routers.