Release Notes for Cisco IOS Release 15.5(1)T

Release Notes for Cisco IOS Release 15.5(1)T

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The following release notes support Cisco IOS Releases 15.5(1)T and higher releases. These releases support the Cisco 5900 Embedded Services Routers (ESR) platforms. These release notes are updated to describe new features, limitations, troubleshooting, recommended configurations, caveats, and how to obtain support and documentation.

Contents

This publication consists of the following sections:

• Image Information and Supported Platforms
• Related Documentation
• Recommended Configuration Settings
• Caveats
• Obtaining Documentation and Submitting a Service Request

Image Information and Supported Platforms

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Note You must have a Cisco.com account to download the software.

Cisco IOS Release 15.5(1)T includes the following Cisco IOS images:

• c5921i86-universalk9-ms.SPA

Related Documentation

The following documentation is available:

• Software Configuration Guide for the Cisco 5900 Embedded Services Routers

http://www.cisco.com/c/en/us/td/docs/solutions/GGSG-Engineering/15-4-3M/config-guide/Configuration-Guide.html

• Cisco 5921 Embedded Services Router Integration Guide

http://www.cisco.com/c/dam/en/us/td/docs/solutions/GGSG-Engineering/Cisco_5921/Cisco_5921_ESR_Integration.pdf

Recommended Configuration Settings

Use the following configuration guidelines when enabling class-based weighted fair-queuing:

• Enter the following command to turn off creation of virtual-template subinterfaces:

• Enter the following commands to create a policy map with class-based weighted fair-queuing and apply the newly created policy-map to the virtual template:

• No additional configuration is supported on the policy-map.

Use the following configuration guidelines when disabling Point to Point Protocol (PPP) keepalives:

• You can turn off the PPP keepalive messages to decrease overhead when the radio alerts the router with a PPPoE Active Discovery Terminate (PADT) message that the layer-2 RF connection is no longer available. Turning off the PPP keepalive messages may also avoid the potential for the router to terminate the connection based on missed PPP keepalives over a poor radio frequency (RF) link.
• To turn off the PPP keepalive messages, enter the following command for the virtual-template:

Use the following configuration guidelines for setting the recommended Open Shortest Path First (OSPF) values of radio link metrics:

• You may have to dampen the amount of changes in order to reduce network-wide churn because cost components may change rapidly.
• The following recommended values are intended as a starting point for optimizing an OSPFv3 network and are based on network simulations that may reduce the rate of network changes. Each network may have unique characteristics that require different settings to optimize actual network performance.

You must configure these values for both OSPFv3 IPv4 and IPv6:

S1 = ipv6 ospf dynamic weight throughout
Recommended value = 0
Default=100
S2 = ipv6 ospf dynamic weight resources
Recommended value = 29
Default = 100
S3 = ipv6 ospf dynamic weight latency
Recommended value = 29
Default = 100
S4 = ipv6 ospf dynamic weight L2 factor
Recommended value = 29
Default = 100

The following is an example configuration for a VMI interface on the virtual template when running bypass mode:

Use the following configuration guidelines for disabling split horizon in EIGRP:

• By default split horizon is enabled in EIGRP. You can disable split horizon by entering the no ip split-horizon eigrp command for the respective autonomous system number.

• Enter the following command to disable the ip redirects on the vmi interface when you are configuring the vmi interface for EIGRP:

Use the following configuration guidelines for setting EIGRP values of radio link metrics:

• EIGRP monitors the following metrics on an interface allowing the tuning of the EIGRP metric calculations; use the metric weights router configuration command:

where tos denotes type of service (currently, it must always be zero) and use the following default values for weights:

k1 - 1

k2 - 0

k3 - 1

k4 - 0

k5 - 0

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Note The no metric weights command restores the K-values to the defaults listed above.

• Most configurations use the Delay and Bandwidth metrics with Bandwidth taking precedence.
• You must set the weights identically on all routers in an autonomous system.

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Note If you wish to use the default K-values you do not need to enter the metric weights command.

• To set the metric dampening value for EIGRP, enter the following commands for either change-based or interval-based dampening of metric updates received through VMI:

– Change Based Dampening:

Default Value for Change Based Dampening:
50%

To enable change-based dampening using the default Value, enter the following command:

To disable change-based dampening, enter the following command:

– Interval-based Dampening:

Default Timer value for Interval-based Dampening:
30 seconds

To enable interval-based dampening using the default Value, enter the following command:

To disable interval-based dampening, enter the following command:

• The following exceptions will result in an immediate update:

– a down interface

– a down route

– any change in a metric triggered outside the scope of the VMI metric update

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Note No recommended values other than default are currently available.

For more information on EIGRP commands, refer to:

http://www.cisco.com/en/US/docs/ios/iproute_eigrp/command/reference/ire_book.html

Use the following configuration guidelines to enable Waas Express:

• Enter the following command to turn Waas Express on the Wan interface:

• Enter the following commands to enable full optimizations:

• Enter the following commands to enable application accelerators:

For more information on Waas Express configuration, refer to the following URLs:

http://www.cisco.com/en/US/docs/ios/wan/configuration/guide/cfg_waas_exp.pdf

http://www.cisco.com/en/US/docs/ios-xml/ios/wan_waas/configuration/15-2mt/wan-cfg-waas-exp.html

Caveats

Caveats describe unexpected behavior in Cisco IOS releases. Caveats listed as open in a prior release are carried forward to the next release as either open or closed (resolved).

Obtaining Documentation and Submitting a Service Request

For information on obtaining documentation, using the Cisco Bug Search Tool (BST), submitting a service request, and gathering additional information, see What’s New in Cisco Product Documentation at: http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html.

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