To configure the Optimized Edge Routing (OER) prefix route dampening timer to set the minimum period of time that a new exit must be used before an alternate exit can be selected, use the holddown command in OER master controller configuration mode. To return the prefix route dampening timer to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

timer : 300

Command Modes

OER master controller configuration (config-oer-mc)

Command History

Usage Guidelines

The holddown command is entered on a master controller. This command is used to configure the prefix route dampening timer to set the minimum period of time that a new exit must be used before an alternate exit can be selected. The master controller puts a prefix in a holddown state during an exit change to isolate the prefix during the transition period to prevent the prefix from flapping because of rapid state changes. OER does not implement policy changes while a prefix is in the holddown state. A prefix will remain in a holddown state for the default or configured time period. When the holddown timer expires, OER will select the best exit based on performance and policy configuration. However, an immediate route change will be triggered if the current exit for a prefix becomes unreachable.

Configuring a new timer value will immediately replace the existing value if the new value is less than the amount of the time remaining. If the new value is greater than the amount of the time remaining, the new timer value will be used when the existing timer is reset.

Related Commands

To configure information about a host device used by an application interface provider to communicate with an Optimized Edge Routing (OER) master controller, use the host-addresscommand in OER master controller application interface provider configuration mode. To remove a host application interface device, use the no form of this command.

Syntax Description

Command Default

A host application interface device is not configured.

Command Modes

OER master controller application interface provider configuration (config-oer-mc-api-provider)

Command History

Usage Guidelines

The OER application interface defines the mode of communication and messaging between applications and the network for the purpose of optimizing the traffic associated with the applications. A provider is defined as an entity outside the network in which the router configured as an OER master controller exists, for example, an ISP, or a branch office of the same company. The provider has one or more host devices running one or more applications that use the OER application interface to communicate with an OER master controller. A provider must be registered with an OER master controller before an application on a host device can interface with OER. Use the api provider command to register the provider, and use the host-addresscommand to configure a host device. After registration, a host device in the provider network can initiate a session with an OER master controller. The OER application interface provides an automated method for networks to be aware of applications and provides application-aware performance routing.

Use the optional priority keyword to specify a priority value for the host device when multiple host devices are configured. The number 1 assigns the highest priority to any requests from the host device. If you assign a priority, each host device must be assigned a different priority number. If you try to assign the same priority number to two different host devices, an error message is displayed on the console.

Related Commands

To configure Optimized Edge Routing (OER) to learn the inside prefixes within a network, use the inside bgp command in OER Top Talker and Top Delay learning configuration mode. To disable prefix learning of inside prefixes, use the no form of this command.

Syntax Description

This command has no arguments or keywords.

Command Default

No inside prefixes are learned by OER.

Command Modes

OER Top Talker and Top Delay learning configuration

Command History

Usage Guidelines

This command is used to implement OER Border Gateway Protocol (BGP) inbound optimization by identifying the prefixes within a network (inside prefixes). OER 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 another autonomous system (for example, an Internet service provider [ISP]) can influence the entrance path for traffic entering the network. OER uses eBGP advertisements to manipulate the best entrance selection.

Related Commands

To configure a border router interface as an Optimized Edge Routing (OER) managed external or internal interface, use the interface command in OER managed border router configuration mode. To remove an interface from OER control, use the no form of this command.

Syntax Description

Command Default

No border router interfaces are configured as OER-managed interfaces.

Command Modes

OER managed border router configuration

Command History

Usage Guidelines

The interface command is entered on a master controller. This command is used to configure external and internal interfaces on border routers to be under OER control. External interfaces are configured as OER managed exit links to forward traffic. External interfaces are used by the master controller to actively monitor prefix and link performance. Internal interfaces are used only for passive performance monitoring with NetFlow.

At least one external and one internal interface must be configured on each border router to allow NetFlow to monitor inbound and outbound traffic. At least two external interfaces are required in an OER managed network. You can configure a maximum of 20 external interfaces for a single master controller in an OER managed network.

In Cisco IOS 15.0(1)M, and later releases, loopback interfaces are supported as external or internal interfaces.

Note	PfR does not support Ethernet interfaces that are Layer 2 only, for example, Ethernet switched interfaces.

Configuring an interface as external enters OER Border Exit configuration mode. Under OER border exit interface configuration mode, you can configure maximum link utilization on a per interface basis with the max-xmit-utilization command.

Note	Entering the interface command without the external or internal keyword, places the router in Global configuration mode and not OER Border Exit configuration mode. The no form of this command should be applied carefully so that active interfaces are not removed from the router configuration.

Related Commands

To specify the threshold jitter value that Optimized Edge Routing (OER) will permit for an exit link, use the jitter command in OER master controller configuration mode. To reset the maximum jitter value to its default value, use the no form of this command.

Syntax Description

Command Default

No jitter values are specified.

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The jitter command is used to specify the maximum tolerable jitter value permitted on an exit link. Jitter is a measure of voice quality where the lower the jitter value, the better the voice quality. If the jitter value is greater than the user-defined or the default value, OER determines that the exit link is out-of-policy and searches for an alternate exit link.

Another measure of voice quality is the estimated Mean Opinion Score (MOS). Use the mos command and the jitter command in an OER policy to define voice quality.

Related Commands

To configure the length of time that an Optimized Edge Routing (OER) master controller will maintain connectivity with an OER border router after no keepalive packets have been received, use the keepalive command in OER master controller configuration mode. To return the keepalive timer to the default time interval, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

timer : 5

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The keepalive command is entered on a master controller. The OER master controller sends keepalive packets to border routers to maintain connectivity between the master controller and the border router. If the master controller does not receive keepalive packets from a border router before the keepalive timer expires and this situation happens three times in a row, then the master controller will not maintain the connection.

Related Commands

To enter OER Top Talker and Top Delay learning configuration mode to configure Optimized Edge Routing (OER) to learn prefixes, use the learn command in OER master controller configuration mode. To disable prefix learning, use the no form of this command.

Syntax Description

This command has no keywords or values.

Command Default

No default behavior or values

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The learn command is entered on a master controller and is used to enter OER Top Talker and Top Delay learning configuration mode to configure a master controller to learn and optimize prefixes based on the highest throughput or the highest delay. Under the Top Talker and Top Delay learning configuration mode, you can configure prefix learning based on delay and throughput statistics. You can configure the length of the prefix learning period, the interval between prefix learning periods, the number of prefixes to learn, and the prefix learning based on protocol.

Related Commands

To configure an Optimized Edge Routing (OER) border router exit interface as a member of a link group, use the link-group command in OER border exit interface configuration mode. To remove a link group from the interface, use the no form of this command.

Syntax Description

Command Default

No link groups are configured for an OER border router exit interface.

Command Modes

OER border exit interface configuration (config-oer-mc-br-if)

Command History

Usage Guidelines

Link groups are used to define a group of exit links as a preferred set of links or a fallback set of links for OER to use when optimizing a specified traffic class. Up to three link groups can be specified for each interface. Configure this command on a master controller to define the link group for an interface and use the set link-group command to define the primary link group and a fallback link group for a specified traffic class in an OER map.

Use the show oer master link-group command to view information about configured OER link groups.

Related Commands

To create an Optimized Edge Routing (OER) learn list to specify criteria for learning traffic classes and to enter learn list configuration mode, use the list command in OER Top Talker and Top Delay learning configuration mode. To remove the learn list, use the no form of this command.

Syntax Description

Command Default

No OER learn lists are created.

Command Modes

OER Top Talker and Top Delay learning configuration (config-oer-mc-learn)

Command History

Usage Guidelines

In Cisco IOS Release 12.4(15)T, the learn list configuration mode was introduced. Learn lists are a way to categorize learned traffic classes. In each learn list, different criteria for learning traffic classes including prefixes, application definitions, filters, and aggregation parameters can be configured. A traffic class is automatically learned by OER based on each learn list criteria, and each learn list is configured with a sequence number. The sequence number determines the order in which learn list criteria are applied. Learn lists allow different OER policies to be applied to each learn list; in previous releases the traffic classes could not be divided, and an OER policy was applied to all the traffic classes profiled during one learning session.

New traffic-class commands were introduced under learn list mode to simplify the learning of traffic classes. Three types of traffic classes--to be automatically learned--can be profiled:

• Traffic classes based on destination prefixes.
• Traffic classes representing custom application definitions using access lists.
• Traffic classes based on a static application mapping name with an optional prefix list filtering to define destination prefixes.

Only one type of traffic-class command can be specified per learn list, and the throughput and delay commands are also mutually exclusive within a learn list.

Related Commands

Note

Effective with Cisco IOS Release 15.0(1)SY, the local command is hidden. Although this command is still available in Cisco IOS software, the CLI interactive Help does not display it if you attempt to view it by entering a question mark at the command line. This command will be completely removed in a future release.

To identify a local interface on an Optimized Edge Routing (OER) border router as the source for communication with an OER master controller, use the local command in OER border router configuration mode. To remove the interface from the OER border router configuration and disable border router to master controller communication, use the no form of this command.

Syntax Description

Command Default

No default behavior or values

Command Modes

OER border router configuration (config-oer-br)

Command History

Usage Guidelines

The local command is configured on an OER border router. This command is used to specify the source interface IP address that will be used for communication between a border router and master controller.

The IP address that is configured for the local interface must also be configured on the master controller with the border OER master controller configuration command and the interface(OER) OER managed border router configuration command.

The no form of this command cannot be entered while the border router process is active. The border router process must first be stopped with the shutdown(OER) command. If you stop the border router process to deconfigure the local interface with the no form of this command, you must configure another local interface before the border router process will reestablish communication with the master controller.

Related Commands

Note

Effective with Cisco IOS Release 15.0(1)SY, the logging command is hidden. Although this command is still available in Cisco IOS software, the CLI interactive Help does not display it if you attempt to view it by entering a question mark at the command line. This command will be completely removed in a future release.

To enable syslog event logging for an Optimized Edge Routing (OER) master controller or an OER border router process, use the logging command in OER master controller or OER border router configuration mode. To disable OER event logging, use the no form of this command.

Syntax Description

This command has no keywords or arguments.

Command Default

No default behavior or values

Command Modes

OER border router configuration (config-oer-br)
OER master controller configuration (config-oer-mc)

Command History

Usage Guidelines

The logging command is entered on a master controller or border router. System logging is enabled and configured in Cisco IOS software under global configuration mode. The loggingcommand in OER master controller or OER border router configuration mode is used only to enable or disable system logging under OER. OER system logging supports the following message types:

Error Messages --These messages indicate OER operational failures and communication problems that can impact normal OER operation.

Debug Messages --These messages are used to monitor detailed OER operations to diagnose operational or software problems.

Notification Messages --These messages indicate that OER is performing a normal operation.

Warning Messages --These messages indicate that OER is functioning properly, but an event outside of OER may be impacting normal OER operation.

To modify system, terminal, destination, and other system global logging parameters, use the logging commands in global configuration mode. For more information about system logging commands, see the Cisco IOS Configuration Fundamentals Command Reference , Release 12.4.

12.2(33)SXH

This command is supported only in OER border router configuration mode.

Related Commands

To set the relative or maximum packet loss limit that Optimized Edge Routing (OER) will permit for an exit link, use the loss command in OER master controller configuration mode. To return the packet loss limit to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

relative average : 100 (10 percent packet loss)

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The loss command is used to specify the relative percentage or maximum number of packets that OER will permit to be lost during transmission on an exit link. If packet loss is greater than the user-defined or the default value, OER determines that the exit link is out-of-policy and searches for an alternate exit link.

The relative keyword is used to configure the relative packet loss percentage. The relative packet loss percentage is based on a comparison of short-term and long-term packet loss. The short-term measurement reflects the percentage of packet loss within a 5-minute period. The long-term measurement reflects the percentage of packet loss within a 60-minute period. The following formula is used to calculate this value:

Relative packet loss = ((short-term loss - long-term loss) / long-term loss) * 100

The master controller measures the difference between these two values as a percentage. If the percentage exceeds the user-defined or default value, the exit link is determined to be out-of-policy. For example, if long-term packet loss is 200 PPM and short-term packet loss is 300 PPM, the relative loss percentage is 50 percent.

The threshold keyword is used to configure the absolute maximum packet loss. The maximum value is based on the actual number of PPM that have been lost.

Related Commands

Note

Effective with Cisco IOS Release 15.0(1)SY, the master command is hidden. Although this command is still available in Cisco IOS software, the CLI interactive Help does not display it if you attempt to view it by entering a question mark at the command line. This command will be completely removed in a future release.

To establish communication with a Optimized Edge Routing (OER) master controller, use the master command in OER border router configuration mode. To disable communication with the specified master controller, use the no form of this command.

Syntax Description

Command Default

No communication is established between a master controller and border router.

Command Modes

OER border router configuration (config-oer-br)

Command History

Usage Guidelines

The master command is entered on a border router. This command is used to establish communication between an OER border router and master controller. Communication is established between the border router process and the master controller process to allow the master controller to monitor and control OER exit links. OER communication must also be established on the master controller with the border OER master controller configuration command. At least one border router must be configured to enable OER. A maximum of ten border routers can be configured to communicate with a single master controller. The IP address that is used to specify the border router must be assigned to a local interface on the border router and must be reachable by the master controller.

By default, passive monitoring in OER observe mode is enabled when communication is established between a master controller and border router. Communication between the master controller and the border router is protected by key-chain authentication. The key-chain configuration is defined in global configuration mode on both the master controller and the border router before key-chain authentication is enabled for master controller to border router communication. For more information about key management in Cisco IOS software, see the "Managing Authentication Keys" section in the "Configuring IP Protocol-Independent Features" chapter of the Cisco IOS IP Routing Protocols Configuration Guide , Release 12.4 .

When the border command is entered, the router enters OER managed border router configuration mode. Local interfaces must be defined as internal or external with the interface(OER) OER managed border router configuration command. A single OER master controller can support up to 20 interfaces.

Related Commands

To reference an extended IP access list or IP prefix as match criteria in an Optimized Edge Routing (OER) map, use the match ip addresscommand in OER map configuration mode. To delete the match clause entry, use the no form of this command.

Syntax Description

Command Default

No match is performed.

Command Modes

OER map configuration

Command History

Usage Guidelines

The match ip addresscommand defines a policy, defined by the oer-map command, to a list of prefixes. The match ip addresscommand is entered on a master controller in OER map configuration mode. This command is used to configure a named extended access list or IP prefix list as a match criteria in an OER map. Only one match clause can be configured for each OER map sequence. The access list is created with the ip access-listcommand. Only named extended IP access lists are supported. The IP prefix list is created with the ip prefix-list command. A prefix can be any IP network number combined with a prefix mask that specifies the prefix length.

The inside keyword is used to support OER BGP inbound optimization that 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. OER uses eBGP advertisements to manipulate the best entrance selection. Inbound BGP only supports the passive mode which results in some configuration restrictions when using an OER map. The following commands are not supported in an OER map for inbound BGP; set active-probe, set interface, set mode monitor, set mode verify bidirectional, set mos threshold, set nexthop, set periodic, set probe frequency, and set traceroute reporting.

Related Commands

To create a match clause entry in an Optimized Edge Routing (OER) map to match OER learned prefixes, use the match oer learncommand in OER map configuration mode. To delete the match clause entry, use the no form of this command.

Syntax Description

Command Default

No match is performed.

Command Modes

OER map configuration

Command History

Usage Guidelines

The match oer learn command is entered on a master controller in OER map configuration mode. OER can be configured to learn prefixes based on delay, inside prefix, or throughput. This command is used to configure OER learned prefixes as match criteria in an OER map. Only one match clause can be configured for each OER map sequence.

Related Commands

To define a match clause using an access list in an Optimized Edge Routing (OER) map to create a traffic class, use the match traffic-class access-list command in OER map configuration mode. To remove the match clause, use the no form of this command.

Syntax Description

Command Default

OER traffic classes are not defined using match criteria in an OER map.

Command Modes

OER map configuration (config-oer-map)

Command History

Usage Guidelines

The match traffic-class access-list command is used to manually configure a traffic class that matches destination prefixes in an access list used in an OER map. Only one access list can be specified, but the access list may contain many access list entries (ACEs) to help define the traffic class.

Note	The match traffic-class access-listcommand, the match traffic-class prefix-list command, and the match traffic-class application commands are all mutually exclusive in an OER map. Only one of these commands can be specified per OER map.

Related Commands

To define a match clause using a static application mapping in an Optimized Edge Routing (OER) map to create a traffic class, use the match traffic-class application command in OER map configuration mode. To remove the match clause entry, use the no form of this command.

Syntax Description

Command Default

OER traffic classes are not defined using match criteria in an OER map.

Command Modes

OER map configuration (config-oer-map)

Command History

Usage Guidelines

The match traffic-class application command is used manually configure the master controller to profile traffic destined for prefixes defined in an IP prefix list that match one or more applications. The applications are predefined with a protocol--TCP or UDP, or both--and one or more ports and this mapping is shown in the table below. More than one application can be configured as part of the traffic class.

Note	The match traffic-class application command, the match traffic-class application nbar command, the match traffic-class access-list command, and the match traffic-class prefix-list commands are all mutually exclusive in an OER map. Only one of these commands can be specified per OER map.

The table below displays the keywords that represent the application that can be configured with the match traffic-class application command. Replace the application-name argument with the appropriate keyword from the table.

Related Commands

To define a match clause using an Network-Based Application Recognition (NBAR) application mapping in an Optimized Edge Routing (OER) map to create a traffic class, use the match traffic-class application nbar command in OER map configuration mode. To remove the match clause entry, use the no form of this command.

Syntax Description

Command Default

OER traffic classes identified using NBAR are not defined using match criteria in an OER map.

Command Modes

OER map configuration (config-oer-map)

Command History

Usage Guidelines

The match traffic-class application nbar command is used to manually configure the master controller to profile traffic destined for prefixes defined in an IP prefix list that match one or more applications identified using NBAR. More than one application can be configured as part of the traffic class with a maximum of ten applications entered per command line. Enter multiple match traffic-class application nbar command statements if you need to specify more than ten applications.

NBAR is capable of identifying applications based on the following three types of protocols:

• Non-UDP and Non-TCP IP protocols--For example, Generic Routing Encapsulation (GRE), and Internet Control Message Protocol (ICMP).
• TCP and UDP protocols that use statically assigned port numbers--For example, CU-SeeMe desktop video conference (CU-SeeMe-Server) andPost Office Protocol over Transport Layer Security (TLS) and Secure Sockets Layer (SSL) server (SPOP3-Server).
• TCP and UDP protocols that dynamically assign port numbers and require stateful inspection--For example, Real-Time Transport Protocol audio streaming (RTP-audio) and BitTorrent File Transfer Traffic (BitTorrent).

Use the match traffic-class application nbar ? command to determine if an application can be identified using NBAR and replace the nbar-appl-name argument with the appropriate keyword from the screen display.

The list of applications identified using NBAR and available for profiling OER or Performance Routing traffic classes is constantly evolving. For lists of many of the NBAR applications defined using static or dynamically assigned ports, see the Using Performance Routing to Profile the Traffic Classes module.

For more details about NBAR, see the Classifying Network Traffic Using NBAR section of the Cisco IOS Quality of Service Solutions Configuration Guide.

Note	The match traffic-class application nbar command, the match traffic-class application command, the match traffic-class access-list command, and the match traffic-class prefix-list commands are all mutually exclusive in an OER map. Only one of these commands can be specified per OER map.

Related Commands

To define a match clause using a prefix list in an Optimized Edge Routing (OER) map to create a traffic class, use the match traffic-class prefix-list command in OER map configuration mode. To remove the match clause, use the no form of this command.

Syntax Description

Command Default

OER traffic classes are not defined using match criteria in an OER map.

Command Modes

OER map configuration (config-oer-map)

Command History

Usage Guidelines

The match traffic-class prefix-list command is used to manually configure a traffic class that matches destination prefixes in a prefix list.

Use the optional inside keyword to specify prefixes that are within the internal network.

Note	The match traffic-class prefix-listcommand, the match traffic-class access-list command, and the match traffic-class application commands are all mutually exclusive in an OER map. Only one of these commands can be specified per OER map.

Related Commands

To set the maximum number of prefixes that an Optimized Edge Routing (OER) master controller will monitor or learn, use the max prefix command in OER master controller configuration mode. To return the master controller to default behavior, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

total number : 5000 learn number: 2500

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The max prefix command is entered on an OER master controller. This command is used to limit the number of prefix that a master controller will monitor and learn to reduce memory and system resource consumption. For more information about memory and system resource consumption, see the Cisco Optimized Edge Routing CPU and Memory Performance Tests document.

Note	If you configure a lower value for the total keyword than the learn keyword, the value for the total keyword will also set the maximum number of prefixes that a master controller will learn.

Related Commands

To set the maximum utilization range for all Optimized Edge Routing (OER) managed entrance links, use the max range receive command in OER master controller configuration mode. To return the maximum utilization range for entrance links to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

percent maximum : 20

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The max range receive command is configured on a master controller. This command is used to set a threshold link utilization range for all entrance interfaces on OER border routers.

OER entrance link range functionality attempts to keep the entrance links within a utilization range, relative to each other to ensure that the traffic load is distributed. The range is specified either as an absolute value in kilobytes per second (kbps) or as a percentage and is configured on the master controller to apply to all the entrance links on border routers managed by the master controller. For example, in an OER-managed network with two entrance links, if the range is specified as 25 percent and the utilization of the first entrance link is 70 percent, then if the utilization of the second entrance link falls to 40 percent, the percentage range between the two entrance links will be more than 25 percent and OER will attempt to move some traffic classes to use the second entrance to even the traffic load.

Related Commands

To set the maximum utilization on a single Optimized Edge Routing (OER) managed entrance link, use the maximum utilization receive command in OER border exit interface configuration mode. To return the maximum utilization on an entrance link to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

percentage bandwidth : 75 .

Command Modes

OER border exit interface configuration

Command History

Usage Guidelines

The maximum utilization receive command is entered on a master controller to set the maximum utilization threshold of incoming traffic that can be transmitted over an OER managed entrance link interface. This command is configured on a per entrance link basis. Use this command with the downgrade bgp command to configure OER BGP inbound optimization. This command can also be used with the max range receive command to configure entrance link load balancing.

If traffic utilization goes above the threshold, OER tries to move the traffic from this entrance link to another underutilized entrance link.

Related Commands

To set the maximum utilization range for all Optimized Edge Routing (OER) managed exit links, use the max-range-utilization command in OER master controller configuration mode. To return the maximum utilization range to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

percent maximum : 20

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The max-range-utilization command is configured on a master controller. This command is used to set a threshold link utilization range for all external interfaces on OER border routers.

OER exit link range functionality attempts to keep the exit links within a utilization range, relative to each other to ensure that the traffic load is distributed. The range is specified as a percentage and is configured on the master controller to apply to all the exit links on border routers managed by the master controller. For example, in an OER-managed network with two exit links, if the range is specified as 25 percent and the utilization of the first exit link is 70 percent, then if the utilization of the second exit link falls to 40 percent, the percentage range between the two exit links will be more than 25 percent and OER will attempt to move some traffic classes to use the second exit to even the traffic load.

Related Commands

To set the maximum utilization on a single Optimized Edge Routing (OER) managed exit link, use the max-xmit-utilization command in OER border exit interface configuration mode. To return the maximum utilization on an exit link to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses the following default value if this command is not configured or if the no form of this command is entered:

percentage bandwidth : 75

Command Modes

OER border exit interface configuration

Command History

Usage Guidelines

The max-xmit-utilization command is entered on a master controller and allows you to set the maximum utilization of outbound traffic that can be transmitted over an OER managed exit interface. The maximum utilization threshold can be expressed as an absolute value in kbps or as a percentage. This command is configured on a per exit link basis and cannot be configured on OER internal interfaces; internal interfaces are not used to forward traffic.

If traffic goes above the threshold, OER tries to move the traffic from this exit link to another underutilized exit link.

Related Commands

To configure route monitoring, route control, or route exit selection on an Optimized Edge Routing (OER) master controller, use the mode command in OER master controller configuration mode. To return the OER master controller to the default monitoring, control, or exit selection state, use the no form of this command.

Syntax Description

Command Default

OER uses the following default settings if this command is not configured or if the no form of this command is entered:

Monitoring: Both active and passive monitoring is enabled. Route control: Observe mode route control is enabled. Exit Selection: The first in-policy exit is selected.

Command Modes

OER master controller configuration (config-oer-mc)

Command History

Usage Guidelines

The mode command is entered on a master controller. This command is used to enable and configure control mode and observe mode settings and is used to configure passive monitoring and active monitoring. A prefix can be monitored both passively and actively.

Observe Mode

Observe mode monitoring is enabled by default. In observe mode, the master controller monitors prefixes and exit links based on default and user-defined policies and then reports the status of the network and the decisions that should be made but does not implement any changes. This mode allows you to verify the effectiveness of this feature before it is actively deployed.

Control Mode

In control mode, the master controller coordinates information from the border routers and makes policy decisions just as it does in observe mode. The master controller monitors prefixes and exits based on default and user-defined policies but then implements changes to optimize prefixes and to select the best exit. In this mode, the master controller gathers performance statistics from the border routers and then transmits commands to the border routers to alter routing as necessary in the OER managed network.

Passive Monitoring

The master controller passively monitors IP prefixes and TCP traffic flows. Passive monitoring is configured on the master controller. Monitoring statistics are gathered on the border routers and then reported back to the master controller. OER uses NetFlow to collect and aggregate passive monitoring statistics on a per prefix basis. No explicit NetFlow configuration is required. NetFlow support is enabled by default when passive monitoring is enabled. OER uses passive monitoring to measure the following information:

Delay --OER measures the average delay of TCP flows for a prefix. Delay is the measurement of the time between the transmission of a TCP synchronization message and receipt of the TCP acknowledgment.

Packet Loss --OER measures packet loss by tracking TCP sequence numbers for each TCP flow. OER estimates packet loss by tracking the highest TCP sequence number. If a subsequent packet is received with a lower sequence number, OER increments the packet loss counter.

Reachability --OER measures reachability by tracking TCP synchronization messages that have been sent repeatedly without receiving a TCP acknowledgment.

Throughput --OER measures outbound throughput for optimized prefixes. Throughput is measured in bits per second (bps).

Note	OER passively monitors TCP traffic flows for IP traffic. Passive monitoring of non-TCP sessions is not supported.

Active Monitoring

OER uses Cisco IOS IP Service Level Agreements (SLAs) to enable active monitoring. IP SLAs support is enabled by default. IP SLAs support allows OER to be configured to send active probes to target IP addresses to measure the jitter and delay, determining if a prefix is out-of-policy and if the best exit is selected. The border router collects these performance statistics from the active probe and transmits this information to the master controller. The master controller uses this information to optimize the prefix and select the best available exit based on default and user-defined policies. The active-probe command is used to create an active probe.

In Cisco IOS Release 12.4(15)T the throughput keyword was added to enable the throughput data from passive mode monitoring to be considered when optimizing UDP traffic for both performance and load balancing. UDP traffic can be optimized only for performance (for example, delay, jitter, and loss) when active monitoring data is available. To enable load balancing of UDP traffic, throughput data from passive monitoring is required.

Fast Failover Monitoring

In Cisco IOS Release 12.4(15)T, a new monitoring mode, fast monitoring, was introduced. Fast monitoring sets the active probes to continuously monitor all the exits (probe-all), and passive monitoring is enabled too. Fast failover monitoring can be used with all types of active probes: ICMP echo, Jitter, TCP connection, and UDP echo. When the mode monitor fast command is enabled, the probe frequency can be set to a lower frequency than for other monitoring modes, to allow a faster failover ability. Under fast monitoring with a lower probe frequency, route changes can be performed within 3 seconds of an out-of-policy situation. When an exit becomes OOP under fast monitoring, the select best exit is operational and the routes from the OOP exit are moved to the best in-policy exit. Fast monitoring is a very aggressive mode that incurs a lot of overhead with the continuous probing. We recommend that you use fast monitoring only for performance sensitive traffic.

Optimal Exit Link Selection

The master controller can be configured to select a new exit for an out-of-policy prefix based on performance or policy. You can configure the master controller to select the first in-policy exit by entering the good keyword, or you can configure the master controller to select the best exit with the best keyword. If the good keyword is used and there is no in-policy exit, the prefix is uncontrolled.

Related Commands

To set the time period in which an Optimized Edge Routing (OER) master controller learns traffic flows, use the monitor-period command in OER Top Talker and Top Delay learning configuration mode. To return the monitoring period to the default time period, use the no form of this command.

Syntax Description

Command Default

If this command is not configured, or if the no form of this command is entered, the default is 5 minutes.

Command Modes

OER Top Talker and Top Delay learning configuration

Command History

Usage Guidelines

The monitor-period command is configured on a master controller. This command is used to adjust the length of time that a master controller learns traffic flows on border routers. The length of time between monitoring periods is configured with the periodic-intervalcommand. The number of prefixes that are learned is configured with the prefixes command.

Related Commands

To specify the threshold and percentage M ean Opinion Score (MOS) values that Optimized Edge Routing (OER) will permit for an exit link, use the mos command in OER master controller configuration mode. To reset the threshold and percentage MOS values to their default value, use the no form of this command.

Syntax Description

Command Default

The default MOS value is 3.60.

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The mos command is used to determine voice quality. The number of MOS samples over a period of time that are below the threshold MOS value are calculated. If the percentage of MOS samples below the threshold is greater than the configured percentage, OER determines that the exit link is out-of-policy and searches for an alternate exit link.

Another measure of voice quality is the jitter value. Use the mos command and the jitter command in an OER policy to define voice quality.

Related Commands

Note

Effective with Cisco IOS Release 15.0(1)SY, the oer command is hidden. Although this command is still available in Cisco IOS software, the CLI interactive Help does not display it if you attempt to view it by entering a question mark at the command line. This command will be completely removed in a future release.

To enable a Cisco IOS Optimized Edge Routing (OER) process and configure a router as an OER border router or as an OER master controller, use the oer command in global configuration mode. To disable a border router or master controller process and delete the OER configuration from the running configuration file, use the no form of this command.

Syntax Description

Command Default

OER is not enabled.

Command Modes

Global configuration (config)

Command History

Usage Guidelines

The oer command is entered on a router to create a border router or master controller process to enable Cisco IOS OER, which allows you to enable automatic outbound route control and load distribution for multihomed and enterprise networks. Configuring OER allows you to monitor IP traffic flows and then define policies and rules based on link performance and link load distribution to alter routing and improve network performance. An OER managed network consists of the following two components:

Master Controller --The master controller is a single router that coordinates all OER functions within an OER managed network. The master controller monitors outbound traffic flows using active or passive monitoring and then applies default and user-defined policies to alter routing to optimize prefixes and exit links. Most OER administration is centralized on the master controller, which makes all policy decisions and controls the border routers. The master controller is not required to be in the traffic forwarding path. The master controller can support up to 10 border routers and up to 20 OER managed external interfaces.

Border Router --The border router is an enterprise edge router with one or more exit links to an Internet service provider (ISP) or other participating network. The border router participates in prefix monitoring and route optimization by reporting prefix and exit link information to the master controller and then enforcing policy changes received from the master controller. Policy changes are enforced by injected a preferred route into the network. The border router is deployed on the edge of the network, so the border router must be in the forwarding path. A border router process can be enabled on the same router as a master controller process (for example, in a small network where all exit interfaces are managed on a single router).

Enabling a Border Router and Master Controller Process on the Same Router

A Cisco router can be configured to perform in dual operation and run a master controller process and border router process on the same router. However, this router will use more memory than a router that is configured to run only a border router process. This factor should be considered when selecting a router for dual operation.

Disabling a Border Router or a Master Controller

To disable a master controller or border router and completely remove the process configuration from the running configuration file, use the no form of this command in Global configuration mode.

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

Enabling Cisco IOS OER for Load Distribution

When enabling Cisco IOS OER for load distribution, we recommend that you set the interface load calculation on OER managed external interfaces to 30-second intervals with the load-interval interface configuration command. The default calculation interval is 300 seconds. The load calculation is configured under interface configuration mode on the border router. This configuration is not required. It is recommended that you allow Cisco IOS OER to respond as quickly as possible to load distribution issues.

Cisco IOS Release 12.2(33)SXH

In Cisco IOS Release 12.2(33)SXH, only the border keyword is supported.

Related Commands

To enter OER map configuration mode to configure an Optimized Edge Routing (OER) map to apply policies to selected IP prefixes, use the oer-map command in global configuration mode. To delete the OER map, use the no form of this command.

Syntax Description

Command Default

No OER maps are created.

Command Modes

Global configuration

Command History

Usage Guidelines

The oer-map command is configured on a master controller. The operation of an OER map is similar to the operation of a route-map. An OER map is designed to select IP prefixes or to select OER learn policies using a match clause and then to apply OER policy configurations using a set clause. The OER map is configured with a sequence number like a route-map, and the OER map with the lowest sequence number is evaluated first. The operation of an OER map differs from a route-map at this point. There are two important distinctions:

• Only a single match clause may be configured for each sequence. An error message will be displayed on the console if you attempt to configure multiple match clauses for a single OER map sequence.
• An OER map is not configured with permit or deny statements. However, a permit or deny sequence can be configured for an IP traffic flow by configuring a permit or deny statement in an IP prefix list and then applying the prefix list to the OER map with the match ip address(OER) command.

Tip	Deny prefixes should be combined in a single prefix list and applied to the OER map with the lowest sequence number.

An OER map can match a prefix or prefix range with the match ip address (OER) command. A prefix can be any IP network number combined with a prefix mask that specifies the prefix length. The prefix or prefix range is defined with the ip prefix-listcommand in global configuration mode. Any prefix length can be specified. An OER map can also match OER learned prefixes with the match oer learn command. Matching can be configured for prefixes learned based on delay or based on throughput.

The OER map applies the configuration of the set clause after a successful match occurs. An OER set clause can be used to set policy parameters for the backoff timer, packet delay, holddown timer, packet loss, mode settings, periodic timer, resolve settings, and unreachable hosts. See the "Related Commands" section of this command reference page for a complete list of OER set clauses.

Policies that are applied by an OER map do not override global policies configured under OER master controller configuration mode and OER Top Talker and Delay learning configuration mode. Policies are overridden on a per-prefix list basis. If a policy type is not explicitly configured in an OER map, the default or configured values will apply. Policies applied by an OER map take effect after the current policy or operational timer expires. The OER map configuration can be viewed in the output of the show running-config command. OER policy configuration can be viewed in the output of the show oer master policy command.

Related Commands

To configure Optimized Edge Routing (OER) to periodically select the best exit link, use the periodic command in OER master controller configuration mode. To disable periodic exit selection, use the no form of this command.

Syntax Description

Command Default

Periodic exit selection is disabled.

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The periodic command is entered on a master controller. This command is used to configure the master controller to evaluate and then make policy decisions for OER managed exit links. When the periodic timer expires, the master controller evaluates current exit links based on default or user-defined policies. If all exit links are in-policy, no changes are made. If an exit link is out-of-policy, the affected prefixes are moved to an in-policy exit link. If all exit links are out-of-policy, the master controller will move out-of-policy prefixes to the best available exit links.

The master controller can be configured to select the first in-policy exit when the periodic timer expires, by configuring the mode command with the select-exit good keywords. The master controller also can be configured to select the best available in-policy exit, by configuring the mode command with the select-exit bestkeywords.

The periodic timer is reset to the default or configured value each time the timer expires. Configuring a new timer value will immediately replace the existing value if the new value is less than the time remaining. If the new value is greater than the time remaining, the new timer value will be used when the existing timer value expires.

Related Commands

To set the time interval between prefix learning periods, use the periodic-intervalcommand in OER Top Talker and Top Delay learning configuration mode. To set the time interval between prefix learning periods to the default value, use the no form of this command.

Syntax Description

Command Default

Optimized Edge Routing (OER) uses the following default value if this command is not configured or if the no form of this command is entered:

minutes : 120

Command Modes

OER Top Talker and Top Delay learning configuration

Command History

Usage Guidelines

The periodic-interval command is configured on a master controller. This command is used to adjust the length of time between traffic flow monitoring periods. The length of time of the learning period is configured with the monitor-period command. The number of prefixes that are monitored is configured with the prefixescommand.

Related Commands

To apply a configuration from an Optimized Edge Routing (OER) map to a master controller configuration, use the policy-rulescommand in OER master controller configuration mode. To remove a configuration applied by the policy-rules command, use the no form of this command.

Syntax Description

Command Default

No configuration is applied to a master controller from an OER map.

Command Modes

OER master controller configuration

Command History

Usage Guidelines

The policy-rules command allows you 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.

The policy-rules command is entered on a master controller. This command is used to apply the configuration from an OER map to a master controller configuration in OER master controller configuration mode.

Reentering this command with a new OER map name will immediately overwrite the previous configuration. This behavior is designed to allow you to quickly select and switch between predefined OER maps.

Related Commands

Note

Effective with Cisco IOS Release 15.0(1)SY, the port command is hidden. Although this command is still available in Cisco IOS software, the CLI interactive Help does not display it if you attempt to view it by entering a question mark at the command line. This command will be completely removed in a future release.

To optionally configure a dynamic port number for communication between an Optimized Edge Routing (OER) master controller and border router, use the port command in OER master controller or OER border router configuration mode. To close the port and disable communication, use the no form of this command.

Syntax Description

Command Default

Port 3949 is used for OER communication unless a dynamic port number is configured on both the master controller and the border router. Port configuration is not shown in the running configuration file when port 3949 is used.

Command Modes

OER border router configuration (config-oer-br)
OER master controller configuration (config-oer-mc)

Command History

Usage Guidelines

Communication between a master controller and border router is automatically carried over port 3949 when connectivity is established. Port 3949 is registered with IANA for OER communication. Manual port number configuration is required only if you are running Cisco IOS Release 12.3(8)T or if you need to configure OER communication to use a dynamic port number.

The portcommand is entered on a master controller or a border router. This command is used to specify a dynamic port number to be used for border router and the master controller communication. The same port number must be configured on both the master controller and border router. Closing the port by entering the no form of this command disables communication between the master controller and the border router.

Cisco IOS Release 12.2(33)SXH

This command is supported only in OER border router configuration mode.

Related Commands

To set the number of prefixes that OER will learn during a monitoring period, use the prefixes command in OER Top Talker and Top Delay learning configuration mode. To return the number of prefixes to the default value, use the no form of this command.

Syntax Description

Command Default

OER uses a default number of 100 prefixes if this command is not configured or if the no form of this command is entered.

Command Modes

OER Top Talker and Top Delay learning configuration

Command History

Usage Guidelines

The prefixes command is configured on a master controller. This command is used to set the number of prefixes that a master controller will learn during a monitoring period. The length of time of the learning period is configured with the monitor-periodcommand. The length of time between monitoring periods is configured with the periodic-intervalcommand.

Related Commands

To configure an Optimized Edge Routing (OER) master controller to learn traffic class entries based on a protocol number or a range of port numbers, use the protocol command in OER Top Talker and Top Delay learning configuration mode. To disable port-based prefix learning, use the no form of this command.

Syntax Description

Command Default

No traffic class entries are learned on the basis of a protocol or port number.

Command Modes

OER Top Talker and Top Delay learning configuration

Command History

Usage Guidelines

The protocol command is configured on a master controller. This command is used to configure prefix learning based on the specified protocol. This command provides a very granular level of control over prefix learning. Configuring this command allows you to configure the master controller to learn prefixes based on the specified protocol and the specified port number.

Port-based prefix learning allows you to include or exclude traffic streams for a specific protocol or the TCP or UDP port and port range. Traffic can be optimized for a specific application or protocol or to exclude uninteresting traffic, allowing you to focus system resources, thus saving CPU cycles and reducing the amount of memory that is required to monitor prefixes. In cases where traffic streams have to be excluded or included over ports that fall above or below a certain port number, a range of port numbers can be specified.

For a list of Internet Assigned Numbers Association (IANA) assigned port numbers, see the following document:

• http://www.iana.org/assignments/port-numbers

For a list of IANA assigned protocol numbers, see the following document:

• http://www.iana.org/assignments/protocol-numbers

Related Commands

To set the priority of a policy when multiple overlapping policies are configured, use the resolve command in OER master controller configuration mode. To disable the policy priority configuration, use the no form of this command.

Syntax Description

Command Default

Optimized Edge Routing (OER) uses the following default settings if this command is not configured or if the no form of this command is entered:

• An unreachable prefix: highest priority
• delay : 11
• utilization : 12

Command Modes

OER master controller configuration (config-oer-mc)

Command History

Usage Guidelines

The resolve command is entered on a master controller. This command is used to set priority when multiple policies are configured for the same prefix. When this command is configured, the policy with the highest priority will be selected to determine the policy decision.

The priority keyword is used to specify the priority value. The number 1 assigns the highest priority to a policy. The number 10 sets the lowest priority. Each policy must be assigned a different priority number. If you try to assign the same priority number to two different policy types, an error message will be displayed on the console. By default, delay has a priority value of 11 and utilization has a priority value of 12. These values can be overridden by specifying a value from 1 to 10.

Note	An unreachable prefix will always have the highest priority regardless of any other settings. This is a designed behavior and cannot be overridden because an unreachable prefix indicates an interruption in a traffic flow.

The variance keyword is used to set an allowable variance for a user-defined policy. This keyword configures the allowable percentage that an exit link or prefix can vary from the user-defined policy value and still be considered equivalent. For example, if an exit link delay is set to 80 absolute and a 10 percent variance is configured, exit links that have delay values from 80 to 89 percent will be considered equal.

Note	Variance cannot be configured for cost or range policies.

Note	You must configure an OER active jitter probe for a target prefix using the active-probe command for the resolve jitter, resolve loss, and resolve mos commands to function.

Related Commands