Performance Routing Border Router Only Functionality

Performance Routing (PfR) introduced support for border router (BR) only functionality on Cisco ASR 1000 series aggregation services routers in Cisco IOS XE Release 2.6.1. On software images that support the border router only functionality, no master controller configuration is available. The master controller that communicates with the border router in this situation must be a router running Cisco IOS Release 15.0(1)M, or a later 15.0M release. In contrast to Performance Routing Border Router Only Functionality on other platforms, Cisco ASR 1000 series routers can provide full border router passive monitoring functionality as well as active monitoring capability. In Cisco IOS XE Release 3.3S, and later releases, master controller configuration is supported.


Note

PfR syntax was introduced in Cisco IOS XE Release 3.1S. If you are running Cisco IOS XE Release 2.6.1 with the Optimized Edge Routing (OER) syntax, you need to consult the Cisco IOS XE Performance Routing Configuration Guide, Release 2.

Prerequisites for PfR Border Router Only Functionality

The Cisco ASR 1000 series aggregation services routers being used as PfR border routers must be running Cisco IOS XE Release 3.1S, or a later release.

Restrictions for PfR Border Router Only Functionality

Only border router functionality is included in the Cisco IOS XE Release 3.1S and 3.2S images; no master controller configuration is available. The master controller that communicates with the Cisco ASR 1000 series router being used as a border router in the Cisco IOS XE Release 3.1S and 3.2S images must be a router running Cisco IOS Release 15.0(1)M, or a later 15.0M release.

Information About PfR Border Router Only Functionality

PfR Border Router Only Functionality on ASR 1000 Series Routers

PfR introduced support for border router (BR) only functionality on Cisco ASR 1000 series aggregation services routers in Cisco IOS XE Release 2.6.1. In Cisco IOS XE Release 3.1S the PfR syntax was introduced. On software images that support the border router only functionality, no master controller configuration is available. The master controller that communicates with the border router in this situation must be a router running Cisco IOS Release 15.0(1)M. In contrast to Border Router Only Functionality on other platforms, Cisco ASR 1000 series routers can provide full border router passive monitoring functionality as well as active monitoring capability.

PfR uses three methods of traffic class performance measurement:

  • Passive monitoring--measuring the performance metrics of traffic class entries while the traffic is flowing through the device using NetFlow functionality. Based on the list of learned and configured prefixes, Performance Routing passively monitors TCP flags for traffic on every flow (of the current exit) to measure latency, packet loss, and reachability. Throughput-based load balancing is still supported.

  • Active monitoring--creating a stream of synthetic traffic replicating a traffic class as closely as possible and measuring the performance metrics of the synthetic traffic. The results of the performance metrics of the synthetic traffic are applied to the traffic class in the master controller database. Active monitoring uses integrated IP Service Level Agreements (IP SLAs) functionality.

  • Both active and passive monitoring--combining both active and passive monitoring in order to generate a more complete picture of traffic flows within the network.

The monitoring mode is configured using the command-line interface (CLI) on a master controller which sends requests to the border routers to enable monitoring modes.

Although the configuration must be performed on a master controller, the border router (BR) only functionality in Cisco ASR 1000 series routers supports the following features:

  • OER Active Probe Source Address--The OER Active Probe Source Address feature allows you to configure a specific exit interface on the border router as the source for active probes. For more details about configuring OER active probe source addresses, see the Configuring Advanced Performance Routing module.

  • OER - Application Aware Routing with Static Application Mapping--The OER - Application Aware Routing with Static Application Mapping feature introduces the ability to configure standard applications using just one keyword. This feature also introduces a learn list configuration mode that allows Performance Routing (PfR) policies to be applied to traffic classes profiled in a learn list. Different policies can be applied to each learn list. New traffic-class and match traffic-class commands are introduced to simplify the configuration of traffic classes that PfR can automatically learn, or that can be manually configured. For more details about configuring OER active probe source addresses, see the Static Application Mapping Using Performance Routing module.

  • OER Support for Policy-Rules Configuration and Port-Based Prefix Learning--The OER Support for Policy-Rules Configuration feature introduced the capability to select an OER map and apply the configuration under OER master controller configuration mode, providing an improved method to switch between predefined OER maps. For more details about configuring policy rules and port-based prefix learning, see the Configuring Advanced Performance Routing module.

  • OER Port and Protocol Based Prefix Learning--The OER Port and Protocol Based Prefix Learning feature introduced the capability to configure a master controller to learn prefixes based on the protocol type and the TCP or UDP port number. For more details about configuring protocol and port-based prefix learning, see the Configuring Advanced Performance Routing module.

  • OER Support for Cost-Based Optimization and Traceroute Reporting--The OER Support for Cost-Based Optimization feature introduced the capability to configure exit link policies based monetary cost and the capability to configure traceroute probes to determine prefix characteristics on a hop-by-hop basis. 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. For more details, see the Configuring Performance Routing Cost Policies or the Performance Routing Traceroute Reporting module.

  • BGP Inbound Optimization--PfR BGP inbound optimization supports best entrance selection for traffic that originates from prefixes outside an autonomous system destined for prefixes inside the autonomous system. External BGP (eBGP) advertisements from an autonomous system to an Internet service provider (ISP) can influence the entrance path for traffic entering the network. PfR uses eBGP advertisements to manipulate the best entrance selection. For more details about configuring BGP inbound optimization, see the BGP Inbound Optimization Using Performance Routing module.


Note

On Cisco ASR 1000 series aggregation services routers in Cisco IOS XE Release 3.1S and later releases, the maximum number of internal prefixes that can be learned during a monitoring period is 30.

  • DSCP Monitoring--OER DSCP Monitoring introduced automatic learning of traffic classes based on protocol, port numbers, and DSCP value. Traffic classes can be defined by a combination of keys comprising of protocol, port numbers, and DSCP values, with the ability to filter out traffic that is not required, and the ability to aggregate the traffic in which you are interested. Layer 4 information such as protocol, port number, and DSCP information is now sent to the master controller database in addition to the Layer 3 prefix information. The new functionality allows OER to both actively and passively monitor application traffic. For more details about configuring policy rules and port-based prefix learning, see the Configuring Advanced Performance Routing module.

  • Performance Routing - Protocol Independent Route Optimization (PIRO)--PIRO introduced the ability of PfR to search for a parent route--an exact matching route, or a less specific route--in the IP Routing Information Base (RIB), allowing PfR to be deployed in any IP-routed environment including Interior Gateway Protocols (IGPs) such as OSPF and IS-IS. For more details about configuring PIRO, see the Performance Routing - Protocol Independent Route Optimization (PIRO) module.

  • Fast Failover Monitoring--Fast Failover Monitoring introduced the ability to configure a fast monitoring mode. In fast failover monitoring mode, all exits are continuously probed using active monitoring and passive monitoring. The probe frequency can be set to a lower frequency in fast failover monitoring mode than for other monitoring modes, to allow a faster failover capability. Fast failover monitoring can be used with all types of active probes: ICMP echo, jitter, TCP connection, and UDP echo. For more details about configuring fast failover monitoring, see the Configuring Advanced Performance Routing module.

  • EIGRP mGRE DMVPN Integration--The PfR EIGRP feature introduces PfR route control capabilities based on EIGRP by performing a route parent check on the EIGRP database. This feature also adds support for mGRE Dynamic Multipoint VPN (DMVPN) deployments that follow a hub-and-spoke network design. For more details about EIGRP route control and mGRE DMVPN support, see the Using Performance Routing to Control EIGRP Routes with mGRE DMVPN Hub-and-Spoke Support module.

  • OER Voice Traffic Optimization--The PfR Voice Traffic Optimization feature provides support for outbound optimization of voice traffic based on the voice metrics, jitter and Mean Opinion Score (MOS). Jitter and MOS are important quantitative quality metrics for voice traffic and these voice metrics are measured using PfR active probes. For more details about configuring policy rules and port-based prefix learning, see the PfR Voice Traffic Optimization Using Active Probes module.

PfR Border Router Operations

PfR is configured on Cisco routers using Cisco IOS command-line interface (CLI) configurations. Performance Routing comprises two components: the Master Controller (MC) and the Border Router (BR). A PfR deployment requires one MC and one or more BRs. Communication between the MC and the BR is protected by key-chain authentication.

The BR component resides within the data plane of the edge router with one or more exit links to an ISP or other participating network.The BR uses NetFlow to passively gather throughput and TCP performance information. The BR also sources all IP service-level agreement (SLA) probes used for explicit application performance monitoring. The BR is where all policy decisions and changes to routing in the network are enforced. The BR participates in prefix monitoring and route optimization by reporting prefix and exit link measurements to the master controller and then by enforcing policy changes received from the master controller. The BR enforces policy changes by injecting a preferred route to alter routing in the network.

How to Configure PfR Border Router Only Functionality

Setting Up a PFR Border Router

Perform this task to set up a PfR border router. This task must be performed at each border router in your PfR-managed network. Communication is first established between the border router and the master controller with key-chain authentication being configured to protect the communication session between the border router and the master controller. A local interface is configured as the source for communication with the master controller, and external interfaces are configured as PfR-managed exit links.

To disable a border router and completely remove the process configuration from the running configuration, use the no pfr border command in global configuration mode.

To temporarily disable a border router process, use the shutdown command in PfR border router configuration mode. Entering the shutdown command stops an active border router process but does not remove any configuration parameters. The shutdown command is displayed in the running configuration file when enabled.

Before you begin

  • Perform the task, Configuring the PfR Master Controller, to set up the master controller and define the interfaces and establish communication with the border routers. Only border router functionality is included in Cisco IOS XE Release 3.1S and 3.2S images; no master controller configuration is available. The master controller that communicates with the Cisco ASR 1000 series router being used as a border router in these images must be a router running Cisco IOS Release 15.0(1)M, or a later 15.0M release. In Cisco IOS XE Release 3.3S, and later releases, master controller configuration is supported.

  • Each border router must have at least one external interface that is either used to connect to an ISP or is used as an external WAN link. A minimum of two external interfaces are required in a PfR-managed network.

  • Each border router must have at least one internal interface. Internal interfaces are used for only passive performance monitoring with NetFlow. Internal interfaces are not used to forward traffic.

  • Each border router must have at least one local interface. Local interfaces are used only for master controller and border router communication. A single interface must be configured as a local interface on each border router.


Note
  • Internet exchange points where a border router can communicate with several service providers over the same broadcast media are not supported.
  • When two or more border routers are deployed in a PfR-managed network, the next hop to an external network on each border router, as installed in the RIB, cannot be an IP address from the same subnet.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. key chain name-of-chain
  4. key key-id
  5. key-string text
  6. exit
  7. Repeat Step 6.
  8. pfr border
  9. local type number
  10. master ip-address key-chain key-chain-name
  11. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Router# configure terminal

Enters global configuration mode.

Step 3

key chain name-of-chain

Example:


Router(config)# key chain border1_PFR

Enables key-chain authentication and enters key-chain configuration mode.

  • Key-chain authentication protects the communication session between both the master controller and the border router. The key ID and key string must match in order for communication to be established.

Step 4

key key-id

Example:


Router(config-keychain)# key 1

Identifies an authentication key on a key chain and enters key-chain key configuration mode.

  • The key ID must match the key ID configured on the master controller.

Step 5

key-string text

Example:


Router(config-keychain-key)# key-string b1

Specifies the authentication string for the key.

  • The authentication string must match the authentication string configured on the master controller.

  • Any level of encryption can be configured.

Step 6

exit

Example:


Router(config-keychain-key)# exit

Exits key-chain key configuration mode and returns to key-chain configuration mode.

Step 7

Repeat Step 6.

Example:


Router(config-keychain)# exit

Exits key-chain configuration mode and returns to global configuration mode.

Step 8

pfr border

Example:


Router(config)# pfr border

Enters PfR border router configuration mode to configure a router as a border router.

  • The border router must be in the forwarding path and contain at least one external and internal interface.

Step 9

local type number

Example:


Router(config-pfr-br)# local GigabitEthernet 0/0/0

Identifies a local interface on a PfR border router as the source for communication with an PfR master controller.

  • A local interface must be defined.

Step 10

master ip-address key-chain key-chain-name

Example:


Router(config-pfr-br)# master 10.1.1.1 key-chain border1_PFR

Enters PfR-managed border router configuration mode to establish communication with a master controller.

  • An IP address is used to identify the master controller.

  • The value for the key-chain-name argument must match the key-chain name configured in Step 3.

Step 11

end

Example:


Router(config-pfr-br)# end

Exits PfR Top Talker and Top Delay learning configuration mode and returns to privileged EXEC mode.

What to Do Next

If your network is configured to use only static routing, no additional configuration is required. The PfR-managed network should be operational, as long as valid static routes that point to external interfaces on the border routers are configured. You can proceed to the Additional References section for links to modules that include information about further PfR customization.

Displaying PfR Border Router Information

Although PfR features are mostly configured on a master controller, the border routers actually collect the performance information and a number of show commands can be run on a border router. The commands in this task are entered on a border router through which the application traffic is flowing. The show commands can be entered in any order.

SUMMARY STEPS

  1. enable
  2. show pfr border
  3. show pfr border active-probes
  4. show pfr border passive prefixes
  5. show pfr border routes {bgp | cce | eigrp [ parent ] | rwatch | static }

DETAILED STEPS

Step 1

enable

Enables privileged EXEC mode. Enter your password if prompted.

Example:


Router> enable

Step 2

show pfr border

Displays information about a PfR border router connection and PfR controlled interfaces.

Example:


Router# show pfr border

OER BR 10.1.1.3 ACTIVE, MC 10.1.1.1 UP/DOWN: UP 00:57:55,
  Auth Failures: 0
  Conn Status: SUCCESS, PORT: 3949
  Exits
  Et0/0           INTERNAL
  Et1/0           EXTERNAL

Step 3

show pfr border active-probes

Displays the target active-probe assignment for a given prefix and the current probing status, including the border router or border routers that are executing the active probes. The following example shows three active probes, each configured for a different prefix. The target port, source IP address, and exit interface are displayed in the output.

Example:


Router# show pfr border active-probes

OER Border active-probes
Type      = Probe Type
Target    = Target IP Address
TPort     = Target Port
Source    = Send From Source IP Address
Interface = Exit interface
Att       = Number of Attempts
Comps   = Number of completions
N - Not applicable
Type     Target          TPort Source          Interface           Att   Comps
udp-echo 10.4.5.1           80 10.0.0.1        Et1/0                 1       0
tcp-conn 10.4.7.1           33 10.0.0.1        Et1/0                 1       0
echo     10.4.9.1            N 10.0.0.1        Et1/0                 2       2

Step 4

show pfr border passive prefixes

This command is used to display passive measurement information collected by NetFlow for PfR monitored prefixes and traffic flows. The following output shows the prefix that is being passively monitored by NetFlow for the border router on which the show pfr border passive prefixes command was run:

Example:


Router# show pfr border passive prefixes
 
OER Passive monitored prefixes:
Prefix         Mask   Match Type
10.1.5.0       /24     exact

Step 5

show pfr border routes {bgp | cce | eigrp [ parent ] | rwatch | static }

This command is used to display information about PfR-controlled routes on a border router. The following example displays EIGRP-controlled routes on a border router with information about the parent route that exists in the EIGRP routing table. In this example, the output shows that prefix 10.1.2.0/24 is being controlled by PfR. This command is used to show parent route lookup and route changes to existing parent routes when the parent route is identified from the EIGRP routing table.

Example:


Router# show pfr border routes eigrp

Flags: C - Controlled by oer, X - Path is excluded from control, 
       E - The control is exact, N - The control is non-exact
Flags Network            Parent             Tag       
CE    10.1.2.0/24        10.0.0.0/8         5000

Configuration Examples for PfR Border Router Only Functionality

Configuring the PfR Master Controller Example

The following configuration example, starting in global configuration mode, shows the minimum configuration required to configure a master controller process to manage the internal network. A key-chain configuration named PFR is defined in global configuration mode.


Note

This configuration is performed on a master controller. Only border router functionality is included in Cisco IOS XE Release 3.1S and 3.2S; no master controller configuration is available. The master controller that communicates with the Cisco ASR 1000 series router being used as a border router must be a router running Cisco IOS Release 15.0(1)M, or a later 15.0M release. In Cisco IOS XE Release 3.3S, and later releases, master controller configuration is supported. 


Router(config)# key chain PFR
Router(config-keychain)# key 1
Router(config-keychain-key)# key-string KEYSTRING2 
Router(config-keychain-key)# end

The master controller is configured to communicate with the 10.100.1.1 and 10.200.2.2 border routers. The keepalive interval is set to 10 seconds. Route control mode is enabled. Internal and external PfR-controlled border router interfaces are defined. 


Router(config)# pfr master
Router(config-pfr-mc)# keepalive 10 
Router(config-pfr-mc)# logging
Router(config-pfr-mc)# border 10.100.1.1 key-chain PFR 
Router(config-pfr-mc-br)# interface GigabitEthernet 0/0/0 external
Router(config-pfr-mc-br)# interface GigabitEthernet 0/0/1 internal 
Router(config-pfr-mc-br)# exit
Router(config-pfr-mc)# border 10.200.2.2 key-chain PFR 
Router(config-pfr-mc-br)# interface GigabitEthernet 0/0/0 external
Router(config-pfr-mc-br)# interface GigabitEthernet 0/0/1 internal 
Router(config-pfr-mc)# exit

Configuring a PfR Border Router Example

The following configuration example, starting in global configuration mode, shows the minimum required configuration to enable a border router. The key-chain configuration is defined in global configuration mode. 


Router(config)# key chain PFR 
Router(config-keychain)# key 1 
Router(config-keychain-key)# key-string KEYSTRING2 
Router(config-keychain-key)# end

The key-chain PFR is applied to protect communication. An interface is identified to the master controller as the local interface (source) for PfR communication. 


Router(config)# pfr border
Router(config-pfr-br)# local GigabitEthernet 1/0/0 
Router(config-pfr-br)# master 192.168.1.1 key-chain PFR 
Router(config-pfr-br)# end

Where to Go Next

After configuring the master controller and border routers, additional configuration may be required to activate the full optimization capabilities of PfR. For more details, see the features supported in Cisco IOS XE as described in the Border Router Only Functionality section, and the Configuring Basic Performance Routing module, or other references in the Related Documents section.

Additional References

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

Cisco IOS PfR commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples

Cisco IOS Performance Routing Command Reference

Basic PfR configuration for Cisco IOS XE releases

“Configuring Basic Performance Routing” module

Information about configuration for the border router only functionality for Cisco IOS XE Releases 3.1 and 3.2

“Performance Routing Border Router Only Functionality” module

Concepts required to understand the Performance Routing operational phases for Cisco IOS XE releases

“Understanding Performance Routing” module

Advanced PfR configuration for Cisco IOS XE releases

“Configuring Advanced Performance Routing” module

IP SLAs overview

“Cisco IOS IP SLAs Overview” module

PfR home page with links to PfR-related content on our DocWiki collaborative environment

PfR:Home

MIBs

MIB

MIBs Link

  • CISCO-PFR-MIB

  • CISCO-PFR-TRAPS-MIB

To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

Technical Assistance

Description

Link

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

http://www.cisco.com/cisco/web/support/index.html

Feature Information for PfR Border Router Only Functionality

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 PfR Border Router Only Functionality

Feature Name

Releases

Feature Information

OER Border Router Only Functionality

Cisco IOS XE Release 2.6.1, Cisco IOS XE Release 3.1S

Performance Routing (PfR) introduced support for border router (BR) only functionality on Cisco ASR 1000 series aggregation services routers in Cisco IOS XE Release 2.6.1. On software images that support the border router only functionality, no master controller configuration is available. The master controller that communicates with the border router in this situation must be a router running Cisco IOS Release 15.0(1)M. In contrast to Border Router Only Functionality on other platforms, Cisco ASR 1000 series routers can provide full border router passive monitoring functionality as well as active monitoring capability.

PfR syntax was introduced in Cisco IOS XE Release 3.1S.

The following commands were introduced or modified by this feature: show pfr border , show pfr border active-probes , show pfr border passive prefixes , show pfr border routes .