Performance Routing (PfR) support for traceroute reporting allows you to monitor prefix performance on a hop-by-hop basis. Delay, loss, and reachability measurements are gathered for each hop from the probe source (border router) to the target prefix.
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
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Information About Performance Routing Traceroute Reporting
Cisco IOS PfR supports standard syslog functions. The notice level of syslog is enabled by default. System logging is enabled and configured in Cisco IOS software under global configuration mode. The logging(PfR) command in PfR master controller or PfR border router configuration mode is used only to enable or disable system logging under PfR. PfR system logging supports the following message types:
Error Messages--These messages indicate PfR operational failures and communication problems that can impact normal PfR operation.
Debug Messages--These messages are used to monitor detailed PfR operations to diagnose operational or software problems.
Notification Messages--These messages indicate that PfR is performing a normal operation.
Warning Messages--These messages indicate that PfR is functioning properly but an event outside of PfR may be impacting normal PfR operation.
Note
With CSCtx06699, PfR syslog levels are added to minimize the number of messages displayed, and a syslog notice is added to display when 30 percent of the traffic classes are out-of-policy.
Note
With CSCts74631, PfR syslog levels are added to minimize the number of messages displayed, a syslog notice is added to display when 30 percent of the traffic classes are out-of-policy, and new syslog alerts are added for a PfR version mismatch, an MC-BR authentication error, and when minimum PfR requirements are not met and the master controller is disabled because there are less than two operational external interfaces.
To modify system, terminal, destination, and other system global logging parameters, use the logging commands in global configuration mode. For more information about global system logging configuration, see to the “Troubleshooting, Logging, and Fault Management” section of the Cisco IOS Network Management Configuration Guide.
PfR Troubleshooting Using Traceroute Reporting
Although PfR provides the ability to diagnose issues using
syslog and
debug command-line interface (CLI) commands, support for traceroute reporting was introduced in the OER Support for Cost-Based Optimization and Traceoute Reporting feature. Using traceroute reporting, PfR reports traffic class performance by determining the delay on a hop-by-hop basis using traceroute probes.
Prior to traceroute reporting there was no method for measuring the delay per hop for situations such as an unexpected round trip delay value being reported for a traffic class on an exit link. PfR uses UDP traceroutes to collect per-hop delay statistics. A traceroute is defined as tracing the route to the device with the given IP address or the hostname and is useful in detecting the location of a problem that exists in the path to the device. Although traditional UDP-based traceroutes are used by default, PfR can be configured to send TCP SYN packets to specific ports that may be permitted through a firewall.
Traceroute reporting is configured on the master controller. Traceroute probes are sourced from the border router exit. This feature allows you to monitor traffic class performance on a hop-by-hop basis. When traceroute reporting is enabled, the autonomous system number, the IP address, and delay measurements are gathered for each hop from the probe source to the target prefix. By default, traceroute probes are sent only when the traffic class goes OOP. TCP-based traceroutes can be configured manually and the time interval between traceroute probes can be modified. By default, per-hop delay reporting is not enabled.
Traceroute probes are configured using the following methods:
Periodic--A traceroute probe is triggered for each new probe cycle. The probe is sourced from the current exit of the traffic class when the option to probe only one exit is selected. If the option to probe all exits is selected, the traceroute probe is sourced from all available exits.
Policy based--A traceroute probe is triggered automatically when a traffic class goes into an out-of-policy state. Traceroute reporting can be enabled for all traffic classes specified in the match clause of an PfR map. Policy based traceroute reporting stops when the traffic class returns to an in-policy state.
On demand--A trace route probe can be triggered on an on demand basis when periodic traceroute reporting is not required, or the per-hop statistics are not required for all paths. Using optional keywords and arguments of the
showpfrmasterprefix command, you can start traceroute reporting for a specific traffic class on a specific path, or all paths.
How to Configure Performance Routing Traceroute Reporting
Perform this task at the master controller to configure traceroute reporting. When using a PfR active probe there are situations when a host address does not respond to the PfR probe message. The reason for no response to the probe message may be due to a firewall or other network issue but PfR assumes the host address to be unreachable and releases control of the prefix. Prior to traceroute reporting there was no method for measuring the delay per hop for situations such as an unexpected round trip delay value being reported for a traffic class on an exit link. The solution for both the non-responding target address and the lack of per-hop delay information involves using UDP, and optionally TCP, traceroutes. Traceroute reporting is configured on a master controller, but the traceroute probes are sourced from the border router exits.
In this task, the three methods of configuring traceroute probes are used. Periodic and policy-based traceroute reporting are configured with the settraceroutereporting (PfR) command using a PfR map. On-demand traceroute probes are triggered by entering the showpfrmasterprefix command with certain parameters. This task also shows to modify the time interval between traceroute probes using the tracerouteprobe-delay (PfR) command.
When traceroute reporting is enabled, the default time interval between traceroute probes is 1000 milliseconds.
SUMMARY STEPS
1.enable
2.configureterminal
3.pfrmaster
4.tracerouteprobe-delaymilliseconds
5.exit
6.pfr-mapmap-namesequence-number
7.matchpfrlearn{delay | throughput}
8.settraceroutereporting[policy {delay | loss | unreachable}]
The following example, starting in global configuration mode, configures continuous traceroute reporting for traffic classes learned on the basis of delay:
Router(config)# pfr master
Router(config-pfr-mc)# traceroute probe-delay 10000
Router(config-pfr-mc)# exit
Router(config)# pfr-map TRACE 10
Router(config-pfr-map)# match pfr learn delay
Router(config-pfr-map)# set traceroute reporting
Router(config-pfr-map)# end
The following example, starting in privileged EXEC mode, initiates an on-demand traceroute probe for the 10.5.5.5 prefix:
Router# show pfr master prefix 10.5.5.55 traceroute current now
Path for Prefix: 10.5.5.0/24 Target: 10.5.5.5
Exit ID: 2, Border: 10.1.1.3 External Interface: Et1/0
Status: DONE, How Recent: 00:00:08 minutes old
Hop Host Time(ms) BGP
1 10.1.4.2 8 0
2 10.1.3.2 8 300
3 10.5.5.5 20 50
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Feature Information for Performance Routing Traceroute Reporting
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 Performance Routing Traceroute Reporting
Feature Name
Releases
Feature Information
OER Support for Cost-Based Optimization and Traceroute Reporting
Cisco IOS XE Release 3.3S
Performance Routing support for traceroute reporting allows you to monitor prefix performance on a hop-by-hop basis. Delay, loss, and reachability measurements are gathered for each hop from the probe source (border router) to the target prefix.
The following commands were introduced or modified by this feature:
settraceroutereporting(PfR),
tracerouteprobe-delay(PfR), and
showpfrmasterprefix.