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Multi-Topology Routing (MTR) allows the configuration of service differentiation through class-based forwarding. MTR supports multiple unicast topologies and a separate multicast topology. A topology is a subset of the underlying network (or base topology) characterized by an independent set of Network Layer Reachability Information (NLRI). A topology can overlap with another or share any subset of the underlying network. MTR provides separate forwarding capabilities on a per topology basis. A separate forwarding table is maintained for each topology, allowing you to broadly apply independent forwarding configurations or add a level of granularity to independent forwarding configurations. MTR can be used, for example, to define separate topologies for voice, video, and data traffic classes.
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 http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
By using MTR, you can configure service differentiation through class-based forwarding. There are two primary components to configuring MTR: independent topology configuration and traffic classification configuration.
A topology is defined as a subset of routers and links in a network for which a separate set of routes is calculated. The entire network itself, for which the usual set of routes is calculated, is known as the base topology. The base topology (or underlying network) is characterized by the NLRI that a router uses to calculate the global routing table to make routing and forwarding decisions. In other words, the base topology is the default routing environment that exists prior to enabling MTR.
Any additional topologies are known as class-specific topologies and are a subset of the base topology. Each class-specific topology carries a class of traffic and is characterized by an independent set of NLRI that is used to maintain a separate Routing Information Base (RIB) and Forwarding Information Base (FIB). This design allows the router to perform independent route calculation and forwarding for each topology.
Within a given router, MTR creates a selection of routes upon which to forward to a given destination. The specific choice of route is based on the class of the packet being forwarded, a class that is an attribute of the packet itself. This design allows packets of different classes to be routed independently from one another. The path that the packet follows is determined by classifiers configured on the routers and interfaces in the network. The figure below shows the base topology, which is a superset of the red, blue, and green topologies.
The figure below shows an MTR-enabled network that is configured using the service separation model. The base topology (shown in black) uses NLRI from all reachable devices in the network. The blue, red, and purple paths each represent a different class-specific topology. Each class-specific topology calculates a separate set of paths through the network. Routing and forwarding are independently calculated based on individual sets of NLRI that are carried for each topology.
The figure below shows that the traffic is marked at the network edge. As the traffic traverses the network, the marking is used during classification and forwarding to constrain the traffic to its own colored topology.
The same topology can have configured backup paths. In the figure below, the preferential path for the voice topology is represented by the solid blue line. In case this path becomes unavailable, you can configure MTR to choose the voice backup path represented by the dotted blue line. Both of these paths represent the same topology and none overlap.
The figure below shows the MTR forwarding model at the system level. When a packet arrives at the incoming interface, the marking is examined. If the packet marking matches a topology, the associated topology is consulted, the next hop for that topology is determined, and the packet is forwarded. If there is no forwarding entry within a topology, the packet is dropped. If the packet does not match any classifier, it is forwarded to the base topology. The outgoing interface is a function of the colored route table in which the lookup is done.
MTR is implemented in Cisco IOS software on a per address family and subaddress family basis. MTR supports up to 32 unicast topologies (including the base topology) and a separate multicast topology. A topology can overlap with another or share any subset of the underlying network. You configure each topology with a unique topology ID. You configure the topology ID under the routing protocol, and the ID is used to identify and group NLRI for each topology in updates for a given protocol.
You can configure up to 32 unicast topologies on each router. You first define the topology by entering the global-address-family command in global configuration mode. The address family and optionally the subaddress family are specified in this step. You then enter the topology subcommand in global address family configuration mode. This command places the router in address family topology configuration mode, and the global topology configuration parameters are applied in this mode.
For each new topology that you configure on a router, you increase the total number of routes from the global routing table by the number of routes that are in each new topology [base+topology(n )]. If the router carries a large global routing table, and you plan to add a significant number of routes through MTR topology configuration, you can configure the maximum routes(MTR) command in address family topology configuration mode to limit the number of routes that the router accepts for a given topology and installs into the corresponding RIB.
Note |
Per-interface topology configuration parameters override configurations applied in global address family topology configuration mode and router address family topology configuration mode. |
For detailed steps, see the Configuring a Unicast Topology for MTR section.
Cisco IOS software supports legacy (pre-MTR) IP multicast behavior by default. MTR support for IP multicast must be explicitly enabled. Legacy IP multicast uses reverse path forwarding on routes in the unicast RIB (base unicast topology) to build multicast distribution trees (MDTs).
MTR introduces a multicast topology that is completely independent from the unicast topology. MTR integration with multicast allows the user to control the path of multicast traffic in the network.
The multicast topology maintains separate routing and forwarding tables. The following list summarizes MTR multicast support that is integrated into Cisco IOS software:
As in pre-MTR software, you enable multicast support by configuring the ip multicast-routing command in global configuration mode. You enable MTR support for multicast by configuring the ip multicast rpf multitopology command. The global-address-family command is entered with the IPv4 address family and multicast subaddress family. You then enter the topology command with the base keyword, and global topology configuration parameters are applied in this mode.
For detailed steps, see the Configuring a Multicast Topology for MTR section.
MTR cannot be enabled on a router until traffic classification is configured, even if only one class-specific topology is configured. Traffic classification is used to configure topology specific forwarding behaviors when multiple topologies are configured on the same router. Traffic classification must be applied consistently throughout the network. Class-specific packets are associated with the corresponding topology table forwarding entries.
Traffic classification is configured by using the Modular QoS CLI (MQC). MTR traffic classification is similar to QoS traffic classification. However, there is an important distinction. MTR traffic classification is defined globally for each topology, rather than at the interface level as in QoS.
A subset of DSCP bits is used to encode classification values in the IP packet header. You configure a class map to define the traffic class by entering the class-map command in global configuration mode. Only the match-any keyword is supported for MTR. You associate the traffic class with a policy by configuring the policy-map type class-routing ipv4 unicast command in global configuration mode. You activate the policy for the topology by configuring the service-policy type class-routing command in global address family configuration mode. When configured, the service policy is associated with all interfaces on the router.
Some of the same goals can be achieved through QoS configuration, to which MTR provides a more powerful and flexible alternative.You can configure MTR traffic classification and IP Differentiated Services or IP Precedence-based traffic classification in the same network. However, MTR requires exclusive use of some subset of the DSCP bits in the IP packet header for specific topology traffic. In a network where MTR and QoS traffic classification are configured, simultaneous configuration must be carefully coordinated.
For detailed steps, see the Configuring MTR Traffic Classification section.
You must enable IP routing on the router for MTR to operate. MTR supports static and dynamic routing in Cisco IOS software. You can enable dynamic routing per-topology to support inter-domain and intra-domain routing. Route calculation and forwarding are independent for each topology. MTR support is integrated into Cisco IOS software for the following protocols:
You apply the per-topology configuration in router address family configuration mode of the global routing process (router configuration mode). The address family and subaddress family are specified when entering address-family configuration mode. You specify the topology name and topology ID by entering the topology command in address-family configuration mode.
You configure each topology with a unique topology ID under the routing protocol. The topology ID is used to identify and group NLRI for each topology in updates for a given protocol. In OSPF, EIGRP, and IS-IS, you enter the topology ID during the first configuration of the topology command for a class-specific topology. In BGP, you configure the topology ID by entering the bgp tid command under the topology configuration.
You can configure class-specific topologies with different metrics than the base topology. Interface metrics configured on the base topology can be inherited by the class-specific topology. Inheritance occurs if no explicit inheritance metric is configured in the class-specific topology.
You configure BGP support only in router configuration mode. You configure Interior Gateway Protocol (IGP) support in router configuration mode and in interface configuration mode.
By default, interfaces are not included in non-base topologies. For routing protocol support for EIGRP, IS-IS, and OSPF, you must explicitly configure a non-base topology on an interface. You can override the default behavior by using the all-interfaces command in address family topology configuration mode. The all-interfaces command causes the non-base topology to be configured on all interfaces of the router that are part of the default address space or the VRF in which the topology is configured.
To implement MTR for BGP, the scope hierarchy is required, but the scope hierarchy is not limited to MTR use. The scope hierarchy introduces some new configuration modes such as router scope configuration mode. You enter router scope configuration mode by configuring the scope command in router configuration mode. When this command is entered, a collection of routing tables is created.
You configure BGP commands under the scope hierarchy for a single network (globally), or on a per-VRF basis, and are referred to as scoped commands. The scope hierarchy can contain one or more address families.
The BGP CLI provides backward compatibility for pre-MTR BGP configuration and provides a hierarchical implementation of MTR. Router configuration mode is backward compatible with the pre-address family and pre-MTR configuration CLI. Global commands that affect all networks are configured in this configuration mode. For address-family and topology configuration, you configure general session commands and peer templates to be used in the address-family or in the topology configuration mode.
After configuring any global commands, you define the scope either globally or for a specific VRF. You enter address family configuration mode by configuring the address-family command in router scope configuration mode or in router configuration mode. Unicast is the default address family if no subaddress family (SAFI) is specified. MTR supports only the IPv4 address family with a SAFI of unicast or multicast.
Entering address family configuration mode from router configuration mode configures BGP to use pre-MTR-based CLI. This configuration mode is backward compatible with pre-existing address family configurations. Entering address family configuration mode from router scope configuration mode configures the router to use the hierarchical CLI that supports MTR. Address family configuration parameters that are not specific to a topology are entered in this address family configuration mode.
You enter BGP topology configuration mode by configuring the topology(BGP) command in address family configuration mode. You can configure up to 32 topologies (including the base topology) on a router. You configure the topology ID by entering the bgp tid command. All address family and subaddress family configuration parameters for the topology are configured here.
Note |
Configuring a scope for a BGP routing process removes CLI support for pre-MTR-based configuration. |
The following example shows the hierarchy levels that are used when configuring BGP for MTR implementation:
router bgp <autonomous-system-number> ! Global commands scope {global | vrf <vrf-name>} ! Scoped commands address-family {<afi>} [<safi>] ! Address family specific commands topology {<topology-name> | base} ! topology specific commands
For detailed steps, see the Activating an MTR Topology by Using BGP section.
MTR is configured under BGP on a per-session basis. The base unicast and multicast topologies are carried in the global (default) session. A separate session is created for each class-specific topology that is configured under a BGP routing process. Each session is identified by its topology ID. BGP performs a best-path calculation individually for each class-specific topology. A separate RIB and FIB are maintained for each session.
Depending on the design and policy requirements for your network, you might need to install routes from a class-specific topology on one router in a class-specific topology on a neighboring router. Topology translation functionality using BGP provides support for this operation. Topology translation is BGP neighbor-session based. You configure the neighbor translate-topology command by using the IP address and topology ID from the neighbor.
The topology ID identifies the class-specific topology of the neighbor. The routes in the class-specific topology of the neighbor are installed in the local class-specific RIB. BGP performs a best-path calculation on all installed routes and installs these routes into the local class-specific RIB. If a duplicate route is translated, BGP selects and installs only one instance of the route per standard BGP best-path calculation behavior.
Topology import functionality using BGP is similar to topology translation. The difference is that routes are moved between class-specific topologies on the same router by using BGP. You configure this function by entering the import topology command and specify the name of the class-specific topology or base topology. Best-path calculations are run on the imported routes before they are installed into the topology RIB. This command also includes a route-map keyword to allow you to filter routes that are moved between class-specific topologies.
For detailed steps, see the Importing Routes from an MTR Topology by Using BGP section.
The configuration of an MTR topology in interface configuration mode allows you to enable or disable MTR on a per-interface basis. By default, a class-specific topology does not include any interfaces.
You can include or exclude individual interfaces by configuring the topology interface configuration command. You specify the address family and the topology (base or class-specific) when entering this command. The subaddress family can be optionally specified. If no subaddress family is specified, the unicast subaddress family is used by default.
You can include globally all interfaces on a router in a topology by entering the all-interfaces command in routing topology configuration mode. Per-interface topology configuration applied with the topology (interface) command overrides global interface configuration.
The interface configuration support for MTR has these characteristics:
For detailed steps, see the Configuring an MTR Topology in Interface Configuration Mode section.
Context-based Simple Network Management Protocol (SNMP) support has been integrated into Cisco IOS software. SNMP support for MTR leverages context-based SNMP to extend support for existing MIBs from representing the management information for just the base topology to representing the same information for multiple topologies.
You can configure the SNMP agent software component on the router to pass a context string to existing MIB access functions. Network management applications can provide these context strings in SNMP transactions to direct those transactions to a specific virtual private network (VPN) routing and forwarding (VRF) instance, a specific topology, and/or routing protocol instance. The SNMP infrastructure on the receiving router verifies that a context string is defined for the router, and that the accompanying internal identifier is defined for that context string, before passing the context string and the internal identifier to the MIB access function.
For detailed steps, see the Configuring SNMP Support for MTR section.
Standard network management utilities, such as ping and traceroute, have been enhanced to support MTR. You can configure a standard or extended ping using the topology name in place of a hostname or IP address. Traceroute has been similarly enhanced. For detailed steps, see the Testing Network Connectivity for MTR section.
All protocols and applications that support MTR and that also support In Service Software Upgrade (ISSU) have extended their ISSU support to include the MTR functionality. See the Cisco IOS In Service Software Upgrade Process module in the Cisco IOS High Availability Configuration Guide for information on ISSU-capable protocols and applications.
ISSU allows a high-availability (HA) system to run in Stateful Switchover (SSO) mode even when different versions of Cisco IOS software are running on the active and standby Route Processors (RPs). This feature allows the system to switch over to a secondary RP that is running upgraded (or downgraded) software and to continue forwarding packets without session loss and with minimal or no packet loss.
This feature is enabled by default.
The base topology is the superset of all topologies in the network. It is defined by NLRI for all reachable routers regardless of the deployment model that is used. MTR can be deployed using the service separation MTR model shown in figure "Service-Separation MTR Model," or it can deployed using the overlapping MTR model shown in figure "Overlapping MTR Model." Each of these models represent a different approach to deploying MTR. However, these models are not mutually exclusive. Any level of variation of a combined model can be deployed.
The figure below shows the service separation model where no colored topologies (except for the base) overlap with each other. In the service separation model, each class of traffic is constrained to its own exclusive topology. This model restricts the given class of traffic to a subset of the network. This model is less configuration intensive because no topology-specific metrics need to be configured.
In the overlapping MTR model, all topologies are configured to run over all routers in the network. This model provides the highest level of redundancy. All classes of traffic can use all links. Per-topology metrics are then configured to bias different classes of traffic to use different parts of the network. The redundancy that this model provides, however, makes it more configuration intensive. The figure below shows the red and gray topologies. All topologies are configured to run over all network routers. In this model, per-topology metrics are configured to bias the preferred routes for each topology.
MTR supports both full and incremental deployment configurations. To support these options, MTR provides two different, configurable forwarding rules: strict forwarding mode for full deployment and incremental forwarding mode for an incremental deployment.
Strict forwarding mode is the default forwarding mode in MTR. In this mode, the router looks for a forwarding route only in the class-specific FIB. If no forwarding route is found, the packet is dropped. In this mode, the router performs a longest match look up for the topology FIB entry. This mode is designed for full deployment, where MTR is enabled on every router in the network or every router in the topology. Strict forwarding mode should be enabled after an incremental deployment transition is been completed or when all routers in the network or topology are MTR enabled. Strict forwarding mode can be enabled after incremental forwarding mode by entering the no forward-base command in address family topology configuration mode.
Incremental forwarding mode is designed to support transitional or incremental deployment of MTR, where routers in the network are not MTR enabled. In this mode, the router looks for a forwarding entry first in the class-specific FIB. If an entry is not found, the router looks for the longest match in the base topology FIB. If an entry is found in the base topology FIB, the packet is forwarded on the base topology. If a forwarding entry is not found in the base topology FIB, the packet is dropped.
This mode is designed to preserve connectivity during an incremental deployment of MTR and is recommended for use only during migration (the transition from a non-MTR to MTR enabled network). Class-specific traffic for a given destination is forwarded over contiguous segments of the class-specific topology containing that destination; otherwise, it is forwarded over the base topology.
This forwarding mode can be enabled to support mixed networks where some routers are not configured to run MTR. Incremental forwarding mode is enabled by entering the forward-base command in address family topology configuration mode.
The section provides guidelines and procedures for enabling or disabling MTR in a production network. These guidelines assume that all participating networking devices are running a software image that supports MTR. They are designed to prevent major traffic interruptions due to misconfiguration and to minimize temporary transitional effects that can occur when introducing or removing a topology from a network. The guidelines described below must be implemented in the order that they are described.
First, create a class-specific topology on all networking devices and enable incremental forwarding mode by entering the forward-base command in the address family topology configuration.Configure incremental forwarding whenever a topology is introduced or removed from the network. The topology is defined as a global container at this stage. No routing or forwarding can occur within the topology. Routing protocol support should not be configured.
Second, configure classification rules for the class-specific topology. You must consistently apply classification on all routers in the topology; each router has identical classifier configuration. You activate the topology when you attach a valid classification configuration to the global topology configuration. You can use ping and trace route to verify reachability for interfaces and networking devices that are in the same topology and configured with identical classification.
Third, configure routing protocol support and/or static routing. Configure the routers in the topology one at a time. This configuration includes interface, router process, and routing protocol-specific metrics and filters.
Enable routing in the topology by using a physical pattern in a contiguous manner relative to a single starting point. For example, configure all interfaces on a single router, and then all interfaces on each adjacent router. Follow this pattern until the task is complete. The starting point can be on the edge or core of the network. This recommendation is designed to increase the likelihood that class-specific traffic is forwarded on the same paths in the incremental topology as it is on the full topology when MTR is completely deployed.
If your network design requires strict forwarding mode, you should disable incremental forwarding only after you configure routing on all routers in a given topology. At this stage, MTR is fully operational. Class-specific traffic is forwarded only over devices within the topology. Traffic that is not classified or destined for the topology is dropped.
When disabling a topology, reenable incremental forwarding mode. Remove custom route configuration, such as route summarization and default routes before disabling a topology, and reapply custom route configuration only after the topology is reenabled. This recommendation is designed to prevent traffic interruption, as some destinations might be obscured during the transition. Custom route configuration is most useful when all of the more specific routes are available in the routing table of the topology.
Note |
These recommendations apply only when a given classifier is enabled or disabled for a given topology. All other MTR configuration, including interface and routing protocol specific configuration (other than the topology ID) can be modified dynamically as necessary. |
Repeat this task for each unicast topology instance that you need to create.
Note |
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Command or Action | Purpose | |||
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Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
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Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
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Step 3 | ip multicast-routing [vrf name] Example: Router(config)# ip multicast-routing |
Enables IP multicast routing. |
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Step 4 | ip multicast rpf multitopology Example: Router(config)# ip multicast rpf multitopology |
Enables MTR support for IP multicast routing. |
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Step 5 | global-address-family ipv4 [multicast | unicast] Example: Router(config)# global-address-family ipv4 multicast |
Enters global address family configuration mode to configure the global topology. |
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Step 6 | topology {base | topology-name} Example: Router(config-af)# topology base |
Configures the global topology instance and enters address family topology configuration mode. |
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Step 7 | route-replicate from {multicast | unicast} [topology {base | name}] protocol [route-map name| vrf name] Example: Router(config-af-topology)# route-replicate from unicast topology VOICE ospf 100 route-map map1 |
(Optional) Replicates (copies) routes from another multicast topology RIB.
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Step 8 | use-topology unicast {base | topology-name} Example: Router(config-af-topology)# use-topology unicast VIDEO |
(Optional) Configures a multicast topology to perform RPF computations using a unicast topology RIB.
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Step 9 | shutdown Example: Router(config-af-topology)# shutdown |
(Optional) Temporarily disables a topology instance without removing the topology configuration (while other topology parameters are configured and other routers are configured with MTR). |
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Step 10 | end Example: Router(config-af-topology)# end |
(Optional) Exits address family topology configuration mode and enters privileged EXEC mode. |
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Step 11 | show topology [cache [topology-ID] | ha | [[detail | interface | lock | router] [all | ipv4 | ipv6 | vrf vpn-instance]] Example: Router# show topology detail |
(Optional) Displays information about class-specific and base topologies. |
The topology is not activated until classification is configured. Proceed to the Configuring MTR Traffic Classification section to configure classification for a class-specific topology.
Note |
Following the correct order of the commands in this task is very important. Ensure that all configuration that affects traffic classification is complete before entering the service-policy type class-routing command. |
Note |
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Command or Action | Purpose | |||
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Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
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Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
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Step 3 | class-map match-any class-map-name Example: Router(config)# class-map match-any VOICE-CLASS |
Creates a class map to be used for matching packets to a specified class and enters class-map configuration mode.
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Step 4 | match [ip] dscp dscp-value[dscp-value dscp-value dscp-value dscp-value dscp-value dscp-value dscp-value] Example: Router(config-cmap)# match ip dscp 9 |
Identifies a DSCP value as a match criteria. |
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Step 5 | exit Example: Router(config-cmap)# exit |
Exits class-map configuration mode. |
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Step 6 | policy-map type class-routing ipv4 unicast policy-map-name Example: Router(config)# policy-map type class-routing ipv4 unicast VOICE-CLASS-POLICY |
Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy and enters policy-map configuration mode. |
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Step 7 | class {class-name | class-default} Example: Router(config-pmap)# class VOICE-CLASS |
Specifies the name of the class whose policy you want to create or change or specifies the default class and enters policy-map class configuration mode. |
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Step 8 | select-topology topology-name Example: Router(config-pmap-c)# select-topology VOICE |
Attaches the policy map to the topology. |
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Step 9 | exit Example: Router(config-pmap-c)# exit |
Exits policy-map class configuration mode. |
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Step 10 | exit Example: Router(config-pmap)# exit |
Exits policy-map configuration mode. |
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Step 11 | global-address-family ipv4 [multicast | unicast] Example: Router(config)# global-address-family ipv4 |
Enters global address family configuration mode to configure MTR. |
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Step 12 | service-policy type class-routing policy-map-name Example: Router(config-af)# service-policy type class-routing VOICE-CLASS-POLICY |
Attaches the service policy to the policy map for MTR traffic classification and activates MTR.
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Step 13 | end Example: Router(config-af)# end |
Exits global address family configuration mode and returns to privileged EXEC mode. |
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Step 14 | show topology detail Example: Router# show topology detail |
(Optional) Displays detailed information about class-specific and base topologies. |
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Step 15 | show policy-map type class-routing ipv4 unicast [interface [interface-type interface-number]] Example: Router# show policy-map type class-routing ipv4 unicast |
(Optional) Displays the class-routing policy map configuration. |
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Step 16 | show mtm table Example: Router# show mtm table |
(Optional) Displays information about the DSCP values assigned to each topology. |
The next four tasks show how to enable MTR support under a routing protocol. Proceed to the Activating an MTR Topology by Using OSPF section to enable routing protocol support.
Note |
Only MTR commands are shown in this task. |
Command or Action | Purpose | |||
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Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
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Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
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Step 3 | router ospf process-id [vrf vrf-name] Example: Router(config)# router ospf 1 |
Enables an OSPF routing process and enters router configuration mode. |
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Step 4 | address-family ipv4 [multicast | unicast] Example: Router(config-router)# address-family ipv4 |
Enter router address family configuration mode to configure an OSPF address family session. |
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Step 5 | topology {base | topology-name tid number} Example: Router(config-router-af)# topology VOICE tid 10 |
Configures OSPF support for the topology and assigns a TID number for each topology. Enters router address family topology configuration mode.
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Step 6 | end Example: Router(config-router-af-topology)# end |
Exits router address family topology configuration mode and returns to privileged EXEC mode. |
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Step 7 | show ip ospf [process-id] topology-info [multicast] [topology{topology-name| base}] Example: Router# show ip ospf topology-info topology VOICE |
(Optional) Displays OSPF information about the specified topology. |
If an EIGRP topology configuration is required, proceed to the next task. If an IS-IS topology configuration is required proceed to the Activating an MTR Topology by Using IS-IS section.
Note |
Only MTR commands are shown in this task. |
Note |
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Command or Action | Purpose | |||
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Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
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Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
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Step 3 | router eigrp name Example: Router(config)# router eigrp MTR |
Configures an EIGRP process for MTR, and enters router configuration mode. |
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Step 4 | address-family ipv4 [unicast | multicast | vrf vrf-name] autonomous-system as-number Example: Router(config-router)# address-family ipv4 autonomous-system 1 |
Enters router address family configuration mode to configure EIGRP for MTR. |
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Step 5 | topology {base | topology-name tid number} Example: Router(config-router-af)# topology VIDEO tid 100 |
Configures an EIGRP process to route IP traffic under the specified topology instance and enters router address family topology configuration mode. |
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Step 6 | end Example: Router(config-router-af-topology)# end |
Exits router address family configuration mode and returns to privileged EXEC mode. |
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Step 7 | show ip protocols topology name [summary] Example: Router# show ip protocols topology VIDEO |
Displays the status of routing protocols configured in a topology.
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Step 8 | show ip eigrp topology name Example: Router# show ip eigrp topology VIDEO |
Displays the routing table of an EIGRP process configured under a topology. |
If an IS-IS topology configuration is required, proceed to the next task. If a BGP topology configuration is required, proceed to the Activating an MTR Topology by Using BGP section.
Note |
Only MTR commands are shown in this task. |
Note |
|
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
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Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
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Step 3 | router isis [area-tag] Example: Router(config)# router isis |
Enables the IS-IS routing protocol and optionally specifies an IS-IS process. Enters router configuration mode. |
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Step 4 | net network-entity-title Example: Router(config-router)# net 31.3131.3131.3131.00 |
Configures an IS-IS network entity title (NET) for a Connectionless Network Service (CLNS) routing process. |
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Step 5 | metric-style wide [transition] [level-1 | level-2 | level-1-2] Example: Router(config-router)# metric-style wide |
Globally changes the metric value for all IS-IS interfaces.
|
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Step 6 | address-family ipv4 [multicast | unicast] Example: Router(config-router)# address-family ipv4 |
Enters router address family configuration mode under IS-IS router configuration mode. |
||
Step 7 | topology topology-name tid number Example: Router(config-router-af)# topology DATA tid 100 |
Configures IS-IS support for the topology and assigns a TID number for each topology. |
||
Step 8 | end Example: Router(config-router-topology)# end |
Exits router address family configuration mode and returns to privileged EXEC mode. |
||
Step 9 | show isis neighbors detail Example: Router# show isis neighbors detail |
(Optional) Displays information about IS-IS neighbors, including MTR information for the TID values for the router and its IS-IS neighbors. |
If a BGP topology configuration is required, proceed to the Activating an MTR Topology by Using BGP section.
Perform this task to activate an MTR topology inside an address family by using BGP. This task is configured on Router B in the figure below and must also be configured on Router D and Router E. In this task, a scope hierarchy is configured to apply globally, and a neighbor is configured under router scope configuration mode. Under the IPv4 unicast address family, an MTR topology that applies to video traffic is activated for the specified neighbor. There is no interface configuration mode for BGP topologies.
Note |
|
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
||
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
||
Step 3 | router bgp autonomous-system-number Example: Router(config)# router bgp 45000 |
Enters router configuration mode to create or configure a BGP routing process. |
||
Step 4 | scope {global | vrf vrf-name} Example: Router(config-router)# scope global |
Defines the scope to the BGP routing process and enters router scope configuration mode.
|
||
Step 5 | neighbor {ip-address| peer-group-name} remote-as autonomous-system-number Example: Router(config-router-scope)# neighbor 172.16.1.2 remote-as 45000 |
Adds the IP address of the neighbor in the specified autonomous system to the multiprotocol BGP neighbor table of the local router. |
||
Step 6 | neighbor {ip-address| peer-group-name} transport{connection-mode {active | passive} | path-mtu-discovery | multi-session | single-session} Example: Router(config-router-scope)# neighbor 172.16.1.2 transport multi-session |
Enables a TCP transport session option for a BGP session.
|
||
Step 7 | address-family ipv4 [mdt | multicast | unicast] Example: Router(config-router-scope)# address-family ipv4 |
Specifies the IPv4 address family and enters router scope address family configuration mode.
|
||
Step 8 | topology {base| topology-name} Example: Router(config-router-scope-af)# topology VIDEO |
Configures the topology instance in which BGP routes class-specific or base topology traffic, and enters router scope address family topology configuration mode. |
||
Step 9 | bgp tid number Example: Router(config-router-scope-af-topo)# bgp tid 100 |
Associates a BGP routing process with the specified topology ID. |
||
Step 10 | neighbor ip-address activate Example: Router(config-router-scope-af-topo)# neighbor 172.16.1.2 activate |
Enables the BGP neighbor to exchange prefixes for the NSAP address family with the local router.
|
||
Step 11 | neighbor {ip-address| peer-group-name} translate-topology number Example: Router(config-router-scope-af-topo)# neighbor 172.16.1.2 translate-topology 200 |
(Optional) Configures BGP to install routes from a topology on another router to a topology on the local router. |
||
Step 12 | end Example: Router(config-router-scope-af-topo)# end |
(Optional) Exits router scope address family topology configuration mode and returns to privileged EXEC mode. |
||
Step 13 | clear ip bgp topology {* | topology-name} {as-number | dampening [network-address [network-mask]] | flap-statistics [network-address [network-mask]] | peer-group peer-group-name | table-map | update-group [number | ip-address]} [in [prefix-filter] | out| soft [in [prefix-filter] | out]] Example: Router# clear ip bgp topology VIDEO 45000 |
Resets BGP neighbor sessions under a specified topology or all topologies. |
||
Step 14 | show ip bgp topology {* | topology} summary Example: Router# show ip bgp topology VIDEO summary |
(Optional) Displays BGP information about a topology.
|
Repeat this task for every topology that you want to enable, and repeat this configuration on all neighbor routers that are to use the topologies.
If you want to import routes from one MTR topology to another on the same router, proceed to the Importing Routes from an MTR Topology by Using BGP section.
Note |
Perform this task to import routes from one MTR topology to another on the same router, when multiple topologies are configured on the same router. In this task, a prefix list is defined to permit prefixes from the 10.2.2.0 network, and this prefix list is used with a route map to filter routes moved from the imported topology. A global scope is configured, address family IPv4 is entered, the VIDEO topology is specified, the VOICE topology is imported, and the routes are filtered using the route map named 10NET. |
Note |
|
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | ip prefix-list list-name [seq seq-value] {deny network / length| permit network / length} [ge ge-value] [le le-value] Example: Router(config)# ip prefix-list TEN permit 10.2.2.0/24 |
Configures an IP prefix list. |
Step 4 | route-map map-name [permit | deny] [sequence-number] Example: Router(config)# route-map 10NET |
Creates a route map and enters route map configuration mode. |
Step 5 | match ip address {access-list-number [access-list-number... | access-list-name...] | access-list-name [access-list-number...| access-list-name] | prefix-list prefix-list-name [prefix-list-name...]} Example: Router(config-route-map)# match ip address prefix-list TEN |
Configures the route map to match a prefix that is permitted by a standard access list, an extended access list, or a prefix list. |
Step 6 | exit Example: Router(config-route-map)# exit |
Exits route map configuration mode and returns to global configuration mode. |
Step 7 | router bgp autonomous-system-number Example: Router(config)# router bgp 50000 |
Enters router configuration mode to create or configure a BGP routing process. |
Step 8 | scope {global | vrf vrf-name} Example: Router(config-router)# scope global |
Defines the scope to the BGP routing process and enters router scope configuration mode.
|
Step 9 | address-family ipv4 [mdt | multicast | unicast] Example: Router(config-router-scope)# address-family ipv4 |
Enters router scope address family configuration mode to configure an address family session under BGP. |
Step 10 | topology {base| topology-name} Example: Router(config-router-scope-af)# topology VIDEO |
Configures the topology instance in which BGP routes class-specific or base topology traffic, and enters router scope address family topology configuration mode. |
Step 11 | import topology {base| topology-name} [route-map map-name] Example: Router(config-router-scope-af-topo)# import topology VOICE route-map 10NET |
(Optional) Configures BGP to move routes from one topology to another on the same router. |
Step 12 | end Example: Router(config-router-scope-af-topo)# end |
(Optional) Exits router scope address family topology configuration mode and returns to privileged EXEC mode. |
Define a topology globally before performing the per-interface topology configuration.
Note |
Interfaces cannot be excluded from the base topology by design. However, IGP can be excluded from an interface in a base topology configuration. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | interface type number Example: Router(config)# interface Ethernet 0/0 |
Specifies the interface type and number, and enters interface configuration mode. |
Step 4 | topology ipv4 [multicast | unicast] {topology-name[disable] | base} Example: Router(config-if)# topology ipv4 VOICE |
Enters interface topology configuration mode to configure an MTR topology instance on an interface.
|
Step 5 | end Example: Router(config-if-topology)# end |
Exits interface topology configuration mode and returns to privileged EXEC mode. |
Define a topology globally before performing the per-interface topology configuration.
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
||
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
||
Step 3 | interface type number Example: Router(config)# interface Ethernet 0/0 |
Specifies the interface type and number, and enters interface configuration mode. |
||
Step 4 | topology ipv4 [multicast | unicast] {topology-name[disable] | base} Example: Router(config-if)# topology ipv4 VOICE |
Enters interface topology configuration mode to configure MTR.
|
||
Step 5 | ip ospf cost number Example: Router(config-if-topology)# ip ospf cost 100 |
Applies a cost to the interface in a topology instance. |
||
Step 6 | ip ospf topology disable Example: Router(config-if-topology)# ip ospf topology disable |
Prevents OSPF from advertising the interface as part of the topology without disabling the OSPF process or the topology on the interface. |
||
Step 7 | end Example: Router(config-if-topology)# end |
Exits interface topology configuration mode and returns to privileged EXEC mode. |
||
Step 8 | show ip ospf [process-id] interface [interface-type interface-number] [brief] [multicast] [topology {topology-name|base}] Example: Router# show ip ospf 1 interface topology VOICE |
(Optional) Displays OSPF-related interface information. |
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
||
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
||
Step 3 | interface type number Example: Router(config)# interface Ethernet 0/0 |
Specifies the interface type and number, and enters interface configuration mode. |
||
Step 4 | topology ipv4 [multicast | unicast] {topology-name[disable] | base} Example: Router(config-if)# topology ipv4 VOICE |
Configures an MTR topology instance on an interface and enters interface topology configuration mode.
|
||
Step 5 | eigrp as-number delay value Example: Router(config-if-topology)# eigrp 1 delay 100000 |
Configures the delay value that EIGRP uses for interface metric calculation. |
||
Step 6 | eigrp as-number next-hop-self Example: Router(config-if-topology)# eigrp 1 next-hop-self |
Configures an EIGRP process to advertise itself as the next hop. |
||
Step 7 | eigrp as-number shutdown Example: Router(config-if-topology)# eigrp 1 shutdown |
Disables an EIGRP process on the interface without disabling the global topology configuration on the interface. |
||
Step 8 | eigrp as-number split-horizon Example: Router(config-if-topology)# eigrp 1 split-horizon |
Configures an EIGRP process to use split horizon. |
||
Step 9 | eigrp as-number summary-address ip-address wildcard-mask [distance] Example: Router(config-if-topology)# eigrp 1 summary-address 10.1.1.0 0.0.0.255 |
Configures an EIGRP summary address. |
||
Step 10 | end Example: Router(config-if-topology)# end |
Exits interface topology configuration mode and returns to privileged EXEC mode. |
||
Step 11 | show ip eigrp topology name interfaces Example: Router# show ip eigrp topology VOICE interfaces |
Displays information about interfaces, on which EIGRP is configured, in a topology. |
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
||
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
||
Step 3 | interface type number Example: Router(config)# interface Ethernet 2/0 |
Specifies the interface type and number, and enters interface configuration mode. |
||
Step 4 | ip address ip-address mask [secondary] Example: Router(config-if)# ip address 192.168.7.17 255.255.255.0 |
Sets a primary or secondary IP address for an interface. |
||
Step 5 | ip router isis [area-tag] Example: Router(config-if)# ip router isis |
Configures an IS-IS routing process for IP on an interface and attaches an area designator to the routing process.
|
||
Step 6 | topology ipv4 [multicast | unicast] {topology-name [disable | base]} Example: Router(config-if)# topology ipv4 DATA |
Configures an MTR topology instance on an interface and enters interface topology configuration mode.
|
||
Step 7 | isis topology disable Example: Router(config-if-topology)# isis topology disable |
(Optional) Prevents an IS-IS process from advertising the interface as part of the topology.
|
||
Step 8 | topology ipv4 [multicast | unicast] {topology-name [disable | base]} Example: Router(config-if-topology)# topology ipv4 VOICE |
Configures an MTR topology instance on an interface.
|
||
Step 9 | end Example: Router(config-if-topology)# end |
Exits interface topology configuration mode and returns to privileged EXEC mode. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | ip vrf vrf-name Example: Router(config)# ip vrf vrfA |
Defines a VRF instance and enters VRF configuration mode. |
Step 4 | snmp context context-name Example: Router(config-vrf)# snmp context context-vrfA |
Creates an SNMP context for MTR for a specific VRF. |
Step 5 | end Example: Router(config-af-topology)# end |
Exits VRF configuration mode and returns to privileged EXEC mode. |
Step 6 | show snmp context mapping Example: Router# show snmp context mapping |
(Optional) Displays information about SNMP contexts for MTR. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | global-address-family ipv4 [multicast | unicast] Example: Router(config)# global-address-family ipv4 |
Enters global address family base topology configuration mode to configure the global topology. |
Step 4 | topology {base | topology-name} Example: Router(config-af)# topology VOICE |
Configures the global topology instance and enters routing topology configuration mode. |
Step 5 | snmp context context-name Example: Router(config-af-topology)# snmp context comp-topol |
Creates an SNMP context for MTR for a specific topology. |
Step 6 | end Example: Router(config-af-topology)# end |
Exits routing topology configuration mode and returns to privileged EXEC mode. |
Step 7 | show snmp context mapping Example: Router# show snmp context mapping |
(Optional) Displays information about SNMP contexts for MTR. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | router ospf process-id [vrf vrf-name] Example: Router(config)# router ospf 1 |
Enables an OSPF routing process and enters router configuration mode. |
Step 4 | snmp context context-name Example: Router(config-router)# snmp context comp-prot |
Creates an SNMP context for MTR for a specific topology under a routing protocol. |
Step 5 | address-family ipv4 [multicast | unicast] Example: Router(config-router)# address-family ipv4 |
Enters global address family configuration mode to configure an OSPF address family session. |
Step 6 | topology {base | topology-name tid number} Example: Router(config-router-af)# topology VOICE tid 10 |
Configures the global topology instance and enters router address family topology configuration mode. |
Step 7 | snmp context context-name Example: Router(config-router-af-topology)# snmp context comp-protocol |
Creates an SNMP context for MTR for a specific topology under a routing protocol. |
Step 8 | end Example: Router(config-router-af-topology)# end |
Exits router address family topology configuration mode and returns to privileged EXEC mode. |
Step 9 | show snmp context mapping Example: Router# show snmp context mapping |
(Optional) Displays information about SNMP contexts for MTR. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | configure terminal Example: Router# configure terminal |
Enters global configuration mode. |
Step 3 | global-address-family ipv4 [multicast | unicast] Example: Router(config)# global-address-family ipv4 |
Enters global address family configuration mode. |
Step 4 | topology accounting Example: Router(config-af)# topology accounting |
Enables topology accounting on all interfaces in the global address family for all IPv4 unicast topologies in the default VRF instance. |
Step 5 | exit Example: Router(config-af)# exit |
Exits global address family configuration mode. |
Step 6 | interface type number Example: Router(config)# interface FastEthernet 1/10 |
Specifies the interface type and number, and enters interface configuration mode. |
Step 7 | ip topology-accounting Example: Router(config-if)# ip topology-accounting |
Enables topology accounting for all IPv4 unicast topologies in the VPN VRF associated with the specified interface. |
Step 8 | end Example: Router(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | show ip interface [type number] [topology{name | all| base}] [stats] Example: Router# show ip interface FastEthernet 1/10 stats |
(Optional) Displays IP traffic statistics for all interfaces or statistics related to the specified interface.
|
Step 3 | show ip traffic [topology{name | all| base}] Example: Router# show ip traffic topology VOICE |
(Optional) Displays global IP traffic statistics (an aggregation of all the topologies when MTR is enabled) or statistics related to a particular topology. |
Step 4 | clear ip interface type number [topology{name | all | base}] [stats] Example: Router# clear ip interface FastEthernet 1/10 topology all |
(Optional) Resets interface-level IP traffic statistics. |
Step 5 | clear ip traffic [topology{name | all| base}] Example: Router# clear ip traffic topology all |
(Optional) Resets IP traffic statistics. |
Command or Action | Purpose | |
---|---|---|
Step 1 | enable Example: Router> enable |
Enables privileged EXEC mode. |
Step 2 | ping [vrf vrf-name| topology topology-name] protocol [target-address] [source-address] Example: Router# ping topology VOICE |
Configures the router to transmit ping messages to the target host in a topology. |
Step 3 | traceroute [vrf vrf-name | topology topology-name] [protocol] destination Example: Router# traceroute VOICE |
Configures the router to trace the specified host in a topology.
|
The following example shows how to create a topology instance named VOICE. This topology is configured to use all operational interfaces on the router. Per the default forwarding rule (strict), only packets destined for routes in the VOICE topology RIB are forwarded. Packets that do not have a topology-specific forwarding entry are dropped.
global-address-family ipv4 topology VOICE all-interfaces end
The following example shows how to create a topology instance named VIDEO. This topology is configured to accept and install a maximum of 1000 routes in the VIDEO topology RIB. Incremental forwarding mode is configured so that the router forwards packets over the base topology if no forwarding entry is found in the class-specific RIB.
global-address-family ipv4 topology VIDEO forward-base maximum routes 1000 90 end
The output of the show topology detail command displays information about class-specific and base topologies. This information includes the address family, associated interfaces, interface and topology status, topology name, and associated VRF.
Router# show topology detail
Topology: base
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: VIDEO
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology fallback is enabled
Topology maximum route limit 1000, warning limit 90% (900)
Associated interfaces:
Topology: VOICE
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology is enabled on all interfaces
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: base
Address-family: ipv4 multicast
Associated VPN VRF is default
Topology state is DOWN
Route Replication Enabled:
from unicast all
Associated interfaces:
The following example shows how to enable multicast support for MTR and to configure a separate multicast topology:
ip multicast-routing ip multicast rpf multitopology ! global-address-family ipv4 multicast topology base end
The following example shows how to configure the multicast topology to replicate OSPF routes from the VOICE topology. The routes are filtered through the BLUE route map before they are installed in the multicast routing table.
ip multicast-routing ip multicast rpf multitopology ! access-list 1 permit 192.168.1.0 0.0.0.255 ! route-map BLUE match ip address 1 exit ! global-address-family ipv4 multicast topology base route-replicate from unicast topology VOICE ospf route-map BLUE
The following example shows how to configure the multicast topology to perform RPF calculations on routes in the VIDEO topology RIB to build multicast distribution trees:
ip multicast-routing ip multicast rpf multitopology ! global-address-family ipv4 multicast topology base use-topology unicast VIDEO end
The following example shows that the multicast topology is configured to replicate routes from the RIB of the VOICE topology:
Router# show topology detail
Topology: base
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: VIDEO
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology fallback is enabled
Topology maximum route limit 1000, warning limit 90% (900)
Associated interfaces:
Topology: VOICE
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology is enabled on all interfaces
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: base
Address-family: ipv4 multicast
Associated VPN VRF is default
Topology state is DOWN
Multicast multi-topology mode is enabled.
Route Replication Enabled:
from unicast topology VOICE all route-map BLUE
Associated interfaces:
The following example shows how to configure classification and activate MTR for two topologies:
global-address-family ipv4 topology VOICE all-interfaces exit topology VIDEO forward-base maximum routes 1000 90 exit exit class-map match-any VOICE-CLASS match ip dscp 9 exit class-map match-any VIDEO-CLASS match ip dscp af11 exit policy-map type class-routing ipv4 unicast MTR class VOICE-CLASS select-topology VOICE exit class VIDEO-CLASS select-topology VIDEO exit exit global-address-family ipv4 service-policy type class-routing MTR end
The following example shows how to display detailed information about the VOICE and VIDEO topologies:
Router# show topology detail
Topology: base
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: VIDEO
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology fallback is enabled
Topology maximum route limit 1000, warning limit 90% (900)
Associated interfaces:
Topology: VOICE
Address-family: ipv4
Associated VPN VRF is default
Topology state is UP
Topology is enabled on all interfaces
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
Topology: base
Address-family: ipv4 multicast
Associated VPN VRF is default
Topology state is DOWN
Multicast multi-topology mode is enabled.
Route Replication Enabled:
from unicast topology VOICE all route-map BLUE
Associated interfaces:
Ethernet0/0, operation state: UP
Ethernet0/1, operation state: DOWN
Ethernet0/2, operation state: DOWN
Ethernet0/3, operation state: DOWN
Loopback0, operation state: UP
The following example shows how to display the classification values for the VOICE and VIDEO topologies:
Router# show mtm table
MTM Table for VRF: default, ID:0
Topology Address Family Associated VRF Topo-ID
base ipv4 default 0
VOICE ipv4 default 2051
Classifier: ClassID:3
DSCP: cs1
DSCP: 9
VIDEO ipv4 default 2054
Classifier: ClassID:4
DSCP: af11
The following example shows how to configure the VOICE topology in an OSPF routing process and set the priority of the VOICE topology to the highest priority:
router ospf 1 address-family ipv4 topology VOICE tid 10 priority 127 end
In the following example, the show ip ospf command is used with the topology-infoand topology keywords to display OSPF information about the topology named VOICE.
Router# show ip ospf 1 topology-info topology VOICE
OSPF Router with ID (10.0.0.1) (Process ID 1)
VOICE Topology (MTID 66)
Topology priority is 64
Redistributing External Routes from,
isis
Number of areas transit capable is 0
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Area BACKBONE(0) (Inactive)
SPF algorithm last executed 16:45:18.984 ago
SPF algorithm executed 3 times
Area ranges are
Area 1
SPF algorithm last executed 00:00:21.584 ago
SPF algorithm executed 1 times
Area ranges are
The following example shows how to activate the VIDEO topology using EIGRP:
router eigrp MTR address-family ipv4 autonomous-system 1 network 10.0.0.0 0.0.0.255 topology VIDEO tid 10 redistribute connected end
The following example shows how to display the status of routing protocols configured in the VIDEO topology. EIGRP information is shown in the output.
Router# show ip protocols topology VIDEO
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Default networks flagged in outgoing updates
Default networks accepted from incoming updates
EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
EIGRP maximum hopcount 100
EIGRP maximum metric variance 1
Redistributing: eigrp 1
EIGRP graceful-restart disabled
EIGRP NSF-aware route hold timer is 240s
Topologies : 100(VOICE) 0(base)
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
Routing Information Sources:
Gateway Distance Last Update
Distance: internal 90 external 170
The following example shows the EIGRP routing table configured under the VIDEO topology:
Router# show ip eigrp topology VIDEO
EIGRP-IPv4 Topology Table for AS(1)/ID(10.1.1.2) Routing Table: VOICE
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 10.1.1.0/24, 1 successors, FD is 281600
via Connected, Ethernet0/0
The following example shows how to configure both the MTR topologies DATA and VIDEO and IS-IS support for MTR. The DATA and VIDEO topologies are enabled on three IS-IS neighbors in a network.
global-address-family ipv4 topology DATA topology VOICE end interface Ethernet 0/0 ip address 192.168.128.2 255.255.255.0 ip router isis topology ipv4 DATA isis topology disable topology ipv4 VOICE end router isis net 33.3333.3333.3333.00 metric-style wide address-family ipv4 topology DATA tid 100 topology VOICE tid 200 end
global-address-family ipv4 topology DATA topology VOICE all-interfaces forward-base maximum routes 1000 warning-only shutdown end interface Ethernet 0/0 ip address 192.168.128.1 255.255.255.0 ip router isis topology ipv4 DATA isis topology disable topology ipv4 VOICE end interface Ethernet 1/0 ip address 192.168.130.1 255.255.255.0 ip router isis topology ipv4 DATA isis topology disable topology ipv4 VOICE end router isis net 32.3232.3232.3232.00 metric-style wide address-family ipv4 topology DATA tid 100 topology VOICE tid 200 end
global-address-family ipv4 topology DATA topology VOICE all-interfaces forward-base maximum routes 1000 warning-only shutdown end interface Ethernet 1/0 ip address 192.168.131.1 255.255.255.0 ip router isis topology ipv4 DATA isis topology disable topology ipv4 VOICE end router isis net 31.3131.3131.3131.00 metric-style wide address-family ipv4 topology DATA tid 100 topology VOICE tid 200 end
Entering the show isis neighbors detail command verifies topology translation with the IS-IS neighbor Router1:
Router# show isis neighbors detail
System Id Type Interface IP Address State Holdtime Circuit Id
R1 L2 Et0/0 192.168.128.2 UP 28 R5.01
Area Address(es): 33
SNPA: aabb.cc00.1f00
State Changed: 00:07:05
LAN Priority: 64
Format: Phase V
Remote TID: 100, 200
Local TID: 100, 200
The following example shows how to configure BGP in the VIDEO topology and how to configure topology translation with the 192.168.2.2 neighbor:
router bgp 45000 scope global neighbor 172.16.1.1 remote-as 50000 neighbor 192.168.2.2 remote-as 55000 neighbor 172.16.1.1 transport multi-session neighbor 192.168.2.2 transport multi-session address-family ipv4 topology VIDEO bgp tid 100 neighbor 172.16.1.1 activate neighbor 192.168.2.2 activate neighbor 192.168.2.2 translate-topology 200 end clear ip bgp topology VIDEO 50000
The following example shows how to configure a global scope for a unicast topology and also for a multicast topology. After exiting the router scope configuration mode, a scope is configured for the VRF named DATA.
router bgp 45000 scope global bgp default ipv4-unicast neighbor 172.16.1.2 remote-as 45000 neighbor 192.168.3.2 remote-as 50000 address-family ipv4 unicast topology VOICE bgp tid 100 neighbor 172.16.1.2 activate exit address-family ipv4 multicast topology base neighbor 192.168.3.2 activate exit exit exit scope vrf DATA neighbor 192.168.1.2 remote-as 40000 address-family ipv4 neighbor 192.168.1.2 activate end
The following example shows summary output for the show ip bgp topology command. Information is displayed about BGP neighbors configured to use the MTR topology named VIDEO.
Router# show ip bgp topology VIDEO summary
BGP router identifier 192.168.3.1, local AS number 45000
BGP table version is 1, main routing table version 1
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
172.16.1.2 4 45000 289 289 1 0 0 04:48:44 0
192.168.3.2 4 50000 3 3 1 0 0 00:00:27 0
The following partial output displays BGP neighbor information under the VIDEO topology:
Router# show ip bgp topology VIDEO neighbors 172.16.1.2
BGP neighbor is 172.16.1.2, remote AS 45000, internal link
BGP version 4, remote router ID 192.168.2.1
BGP state = Established, up for 04:56:30
Last read 00:00:23, last write 00:00:21, hold time is 180, keepalive interval is 60
seconds
Neighbor sessions:
1 active, is multisession capable
Neighbor capabilities:
Route refresh: advertised and received(new)
Message statistics, state Established:
InQ depth is 0
OutQ depth is 0
Sent Rcvd
Opens: 1 1
Notifications: 0 0
Updates: 0 0
Keepalives: 296 296
Route Refresh: 0 0
Total: 297 297
Default minimum time between advertisement runs is 0 seconds
For address family: IPv4 Unicast topology VIDEO
Session: 172.16.1.2 session 1
BGP table version 1, neighbor version 1/0
Output queue size : 0
Index 1, Offset 0, Mask 0x2
1 update-group member
Topology identifier: 100
.
.
.
Address tracking is enabled, the RIB does have a route to 172.16.1.2
Address tracking requires at least a /24 route to the peer
Connections established 1; dropped 0
Last reset never
Transport(tcp) path-mtu-discovery is enabled
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Minimum incoming TTL 0, Outgoing TTL 255
Local host: 172.16.1.1, Local port: 11113
Foreign host: 172.16.1.2, Foreign port: 179
.
.
.
The following example shows how to configure an access list to be used by a route map named BLUE to filter routes imported from the MTR topology named VOICE. Only routes with the prefix 192.168.1.0 are imported.
access-list 1 permit 192.168.1.0 0.0.0.255 route-map BLUE match ip address 1 exit router bgp 50000 scope global neighbor 10.1.1.2 remote-as 50000 neighbor 172.16.1.1 remote-as 60000 address-family ipv4 topology VIDEO bgp tid 100 neighbor 10.1.1.2 activate neighbor 172.16.1.1 activate import topology VOICE route-map BLUE end clear ip bgp topology VIDEO 50000
The following example shows how to disable the VOICE topology on Ethernet interface 0/0.
interface Ethernet 0/0 topology ipv4 VOICE disable
The following example shows how to disable OSPF routing on interface Ethernet 0/0 without removing the interface from the global topology configuration:
interface Ethernet 0/0 topology ipv4 VOICE ip ospf cost 100 ip ospf topology disable end
In the following example, the show ip ospf interface command is used with the topology keyword to display information about the topologies configured for OSPF in interface configuration mode.
Router# show ip ospf 1 interface topology VOICE
VOICE Topology (MTID 66)
Serial3/0 is up, line protocol is up
Internet Address 10.0.0.5/30, Area 1
Process ID 1, Router ID 44.44.44.44, Network Type POINT_TO_POINT
Topology-MTID Cost Disabled Shutdown Topology Name
4 77 no no grc
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:05
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 1/4, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.2.2.2
Suppress hello for 0 neighbor(s)
In the following example, the show ip ospf interface command is used with the briefand topology keywords to display information about the topologies configured for OSPF in interface configuration mode.
Router# show ip ospf 1 interface brief topology VOICE
VOICE Topology (MTID 66)
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Se3/0 1 1 10.0.0.5/30 1 UP 0/0
Se2/0 1 1 10.0.0.1/30 1 UP 0/0
The following example shows how to set the EIGRP delay calculation on interface Ethernet 0/0 to 100 milliseconds:
interface Ethernet 0/0 topology ipv4 VOICE eigrp 1 delay 100000 eigrp 1 next-hop-self eigrp 1 shutdown eigrp 1 split-horizon eigrp 1 summary-address 10.1.1.0 0.0.0.255 end
The following example shows how to display EIGRP information about interfaces in the VOICE topology:
Router# show ip eigrp topology VOICE interfaces
EIGRP-IPv4 interfaces for process 1
Xmit Queue Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes
Et0/0 1 0/0 20 0/2 0 0
The following example shows how to display EIGRP information about links in the VOICE topology:
Router# show ip eigrp topology VOICE detail-links
EIGRP-IPv4 Topology Table for AS(1)/ID(10.1.1.1) Routing Table: VOICE
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 10.1.1.0/24, 1 successors, FD is 25856000, serno 5
via Connected, Ethernet0/0
The following example shows how to prevent the IS-IS process from advertising interface Ethernet 1/0 as part of the DATA topology:
interface Ethernet 1/0 ip address 192.168.130.1 255.255.255.0 ip router isis topology ipv4 DATA isis topology disable topology ipv4 VOICE end
In the following example, the context string “context-vrfA” is configured to be associated with vrfA and will be passed on to the MIB access function during SNMP transactions:
snmp-server community public ip vrf vrfA snmp context context-vrfA exit
In the following example, the context string “context-voice” is configured to be associated with the data topology named voice and will be passed on to the MIB access function during SNMP transactions:
global-address-family ipv4 topology voice snmp context context-voice exit
In the following example, the context strings “context-ospf” and “context-voice” are configured to be associated with the OSPF process and topology named voice and will be passed on to the MIB access function during SNMP transactions:
router ospf 3 snmp context context-ospf address-family ipv4 topology voice tid 10 snmp context ospf-voice end
The following example shows how the context strings are mapped to the specified VRF, address family, topology, or protocol instance:
Router# show snmp context mapping
Context: ospf-voice
VRF Name:
Address Family Name: ipv4
Topology Name: voice
Protocol Instance: OSPF-3 Router
Context: context-ospf
VRF Name:
Address Family Name:
Topology Name:
Protocol Instance: OSPF-3 Router
Context: context-vrfA
VRF Name: vrfA
Address Family Name:
Topology Name:
Protocol Instance:
Context: context-voice
VRF Name:
Address Family Name: ipv4
Topology Name: voice
Protocol Instance:
In the following example, the show ip interface command is used with the type number arguments to display IP traffic statistics for the Fast Ethernet interface 1/10:
Router# show ip interface FastEthernet 1/10 stats
FastEthernet1/10
5 minutes input rate 0 bits/sec, 0 packet/sec,
5 minutes output rate 0 bits/sec, 0 packet/sec,
201 packets input, 16038 bytes
588 packets output, 25976 bytes
In this example, the show ip trafficcommand is used with the topology instance keyword and argument to display statistics related to a particular topology:
Router# show ip traffic topology VOICE
Topology: VOICE
5 minute input rate 0 bits/sec, 0 packet/sec,
5 minute output rate 0 bits/sec, 0 packet/sec,
100 packets input, 6038 bytes,
88 packets output, 5976 bytes.
The following example shows how to send a ping to the 10.1.1.2 neighbor in the VOICE topology:
Router# ping topology VOICE 10.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
The following example shows how to trace the 10.1.1.4 host in the VOICE topology:
Router# traceroute VOICE ip 10.1.1.4
Type escape sequence to abort.
Tracing the route to 10.1.1.4
1 10.1.1.2 4 msec * 0 msec
2 10.1.1.3 4 msec * 2 msec
3 10.1.1.4 4 msec * 4 msec
Related Topic |
Document Title |
---|---|
Cisco IOS commands |
|
MTR commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
Cisco IOS Multi-Topology Routing Command Reference |
IP routing protocol commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
Cisco IOS IP Routing: BGP Command Reference Cisco IOS IP Routing: EIGRP Command Reference Cisco IOS IP Routing: ISIS Command Reference Cisco IOS IP Routing: OSPF Command Reference |
IP multicast commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
Cisco IOS IP Multicast Command Reference |
QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples |
Cisco IOS IP Quality of Service Solutions Command Reference |
IP routing protocols concepts and tasks |
Cisco IOS IP Routing: BGP Configuration Guide Cisco IOS IP Routing: EIGRP Configuration Guide Cisco IOS IP Routing: ISIS Configuration Guide Cisco IOS IP Routing: OSPF Configuration Guide |
IP multicast concepts and tasks |
Cisco IOS IP Multicast Configuration Guide |
QoS concepts and tasks |
Cisco IOS IP Quality of Service Solutions Configuration Guide |
Configuring Multitopology IS-IS for IPv6 |
Implementing IS-IS for IPv6 module in the Cisco IOS IPv6 Configuration Guide |
Cisco IOS In Service Software Upgrade Process |
Cisco IOS In Service Software Upgrade module in the Cisco IOS High Availability Configuration Guide |
Standard |
Title |
---|---|
No new or modified standards are supported, and support for existing standards has not been modified. |
-- |
MIB |
MIBs Link |
---|---|
No new or modified MIBs are supported, and support for existing MIBs has not been modified. |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFC |
Title |
---|---|
No new or modified RFCs are supported, and support for existing RFCs has not been modified. |
-- |
Description |
Link |
---|---|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
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 http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Feature Name |
Releases |
Feature Information |
---|---|---|
Multi-Topology Routing |
12.2(33)SRB 15.0(1)S |
MTR introduces the capability to configure service differentiation through class-based forwarding. MTR provides multiple logical topologies over a single physical network. Service differentiation can be achieved by forwarding different traffic types over different logical topologies that could take different paths to the same destination. MTR can be used, for example, to define separate topologies for voice, video, and data traffic classes. The following commands were introduced or modified: all-interfaces, clear ip interface, clear ip route topology, clear ip traffic, debug topology, exit-global-af, exit-if-topology, exit-topo, forward-base, global-address-family ipv4, ip route topology, ip topology accounting, maximum routes, ping, route replicate, show ip interface, show ip protocols topology, show ip route topology, show ip static route, show ip static route summary, show ip traffic, show topology, shutdown, topology, topology accounting, traceroute. |
BGP Support for MTR |
12.2(33)SRB 15.0(1)S |
This feature provides BGP support for multiple logical topologies over a single physical network. The following commands were introduced or modified: address-family ipv4, bgp tid, clear ip bgp topology, import topology, neighbor translate-topology, neighbor transport, show ip bgp topology, scope, topology, |
EIGRP Support for MTR |
12.2(33)SRB 15.0(1)S |
This feature provides EIGRP support for multiple logical topologies over a single physical network. The following commands were introduced or modified: address-family ipv4, eigrp delay, clear ip eigrp neighbor, eigrp next-hop-self, eigrp shutdown, eigrp split-horizon, eigrp summary-address, router eigrp, show ip eigrp topology, topology. |
IS-IS Support for MTR |
12.2(33)SRB |
This feature provides IS-IS support for multiple logical topologies over a single physical network. The following commands were introduced or modified: address-family ipv4, isis topology disable, show isis neighbors, topology, |
ISSU--MTR |
12.2(33)SRB1 |
All protocols and applications that support MTR and also support ISSU have extended their ISSU support to include the MTR functionality. No commands were introduced or modified in this feature. |
MTR Support for Multicast |
12.2(33)SRB 15.0(1)M |
This feature provides MTR support for multicast and allows the user to control the path of multicast traffic in the network. The following commands were introduced or modified: clear ip route multicast, ip multicast rpf multitopology, show ip route multicast, use-topology. |
OSPF Support for MTR |
12.2(33)SRB |
This feature provides OSPF support for multiple logical topologies over a single physical network. The following commands were introduced or modified: address-family ipv4, area capability default-exclusion, ip ospf cost, ip ospf topology disable, priority, router ospf, show ip ospf interface, show ip ospf topology-info, topology. |
QoS/MQC Support for MTR |
12.2(33)SRB 15.0(1)S |
This feature enables MTR traffic classification. Traffic classification is used to associate different classes of traffic with different topologies when multiple topologies are configured on the same router. A subset of DSCP bits is used to encode classification values in the IP packet header and mark the packet for classification. When MTR traffic classification is enabled, MTR is activated and ready for the routing protocols to start contributing to the topologies. The following commands were introduced or modified: policy-map type class-routing ipv4 unicast, select topology, service-policy type class-routing, show mtm table, show policy-map type class-routing ipv4 unicast. |
SNMP Support for MTR |
12.2(33)SRB 12.2(33)SB 15.0(1)S |
Context-based SNMP functionality has been integrated into Cisco IOS software and can be used to support MTR. SNMP support for MTR leverages context-based SNMP to extend support for existing MIBs from representing the management information for just the base topology to representing the same information for multiple topologies. The following commands were introduced or modified: show snmp context mapping, snmp context. |
base topology --The entire network for which the usual set of routes are calculated. This topology is the same as the default global routing table that exists today without MTR being used.
class-specific topology --New topologies that are defined over and above the existing base topology; each class-specific topology is represented by its own RIB and FIB.
classification --Selection and matching of traffic that needs to be provided with a different treatment based on its mark. Classification is a read-only operation.
DSCP --DiffServ Code Point. Six bits in the ToS. (Two bits are now used for Explicit Congestion Notification.) These are the bits used to mark the packet.
incremental forwarding mode --Incremental forwarding mode is designed to support transitional or incremental deployment of MTR, where there are routers in the network that are not MTR enabled. In this mode, the router will look for a forwarding entry first in the class-specific FIB. If an entry is not found, the router will then look for the longest match in the base topology FIB. If an entry is found in the base topology FIB, the packet will be forwarded on the base topology. If a forwarding entry is not found in the base topology FIB, the packet is dropped.
marking --Setting a value in the packet or frame. Marking is a read and write operation.
multi-topology --Multi-topology means that each topology will route/forward a subset of the traffic as defined by the classification criteria.
NLRI --Network Layer Reachability Information.
strict forwarding mode --Strict forwarding mode is the default forwarding mode for MTR. Only routes in the topology specific routing table are considered. Among these, the longest match for the destination address is used. If no route containing the destination address can be found in the topology specific table, the packet is dropped.
TID --Topology Identifier. Each topology is configured with a unique topology ID. The topology ID is configured under the routing protocol and is used to identify and group NLRI for each topology in updates for a given protocol.
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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.
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