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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
The
Cisco Support website provides extensive online resources, including
documentation and tools for troubleshooting and resolving technical issues with
Cisco products and technologies.
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to most tools on the Cisco Support website requires a Cisco.com user ID and
password.
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.
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