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Cisco IOS Software Releases 12.0 S

MPLS Traffic Engineering (TE)--Class-Based Tunnel Selection

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MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Contents

Prerequisites for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Restrictions for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Information About MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Incoming Traffic Supported by MPLS TE Class-based Tunnel Selection

CoS Attributes for MPLS TE Class-based Tunnel Selection

Routing Protocols and MPLS TE Class-based Tunnel Selection

Tunnel Selection with MPLS TE Class-based Tunnel Selection

EXP Mapping Configuration

Tunnel Selection for EXP Values

Tunnel Failure Handling

Misordering of Packets

Fast Reroute and MPLS TE Class-based Tunnel Selection

DS-TE Tunnels and MPLS TE Class-based Tunnel Selection

Reoptimization and MPLS TE Class-based Tunnel Selection

Interarea and Inter-AS and MPLS TE Class-based Tunnel Selection

ATM PVCs and MPLS TE Class-based Tunnel Selection

How to Configure MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend

Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel

Making the MPLS TE or DS-TE Tunnels Visible for Routing

Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP

Configuring a Master Tunnel

Configuration Examples for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend: Example

Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel: Example

Making the MPLS TE or DS-TE Tunnels Visible for Routing: Example

Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP: Example

Configuring a Master Tunnel: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

show ip cef

show mpls forwarding-table

show mpls traffic-eng tunnels

tunnel mpls traffic-eng exp

tunnel mpls traffic-eng exp-bundle master

tunnel mpls traffic-eng exp-bundle member

Feature Information for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

Glossary


MPLS Traffic Engineering (TE): Class-based Tunnel Selection

First Published: November 1, 2003
Last Updated: August 8, 2007

The MPLS Traffic Engineering (TE): Class-based Tunnel Selection feature enables you to dynamically route and forward traffic with different class of service (CoS) values onto different TE tunnels between the same tunnel headend and the same tailend. The TE tunnels can be regular TE or DiffServ-aware TE (DS-TE) tunnels.

The set of TE (or DS-TE) tunnels from the same headend to the same tailend that you configure to carry different CoS values is referred to as a "tunnel bundle." After configuration, CBTS dynamically routes and forwards each packet into the tunnel that:

•Is configured to carry the CoS of the packet

•Has the right headend for the destination of the packet

Because Class-Based Tunnel Selection (CBTS) offers dynamic routing over DS-TE tunnels and requires minimum configuration, it greatly eases deployment of DS-TE in large-scale networks.

CBTS can distribute all CoS values on eight different tunnels.

CBTS also allows the TE tunnels of a tunnel bundle to exit headend routers through different interfaces.

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for MPLS Traffic Engineering (TE): Class-based Tunnel Selection" section.

Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Contents

•Prerequisites for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Restrictions for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Information About MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•How to Configure MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Configuration Examples for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Additional References

•Command Reference

•Feature Information for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Glossary

Prerequisites for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•Multiprotocol Label Switching (MPLS) must be enabled on all tunnel interfaces.

•Cisco Express Forwarding or distributed Cisco Express Forwarding must be enabled in global configuration mode.

Restrictions for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

•For a given destination, all CoS values are carried in tunnels terminating at the same tailend. Either all CoS values are carried in tunnels or no values are carried in tunnels. In other words, for a given destination, you cannot map some CoS values in a DS-TE tunnel and other CoS values in a Shortest Path First (SPF) Label Distribution Protocol (LDP) or SPF IP path.

•CBTS does not allow load-balancing of a given experimental (EXP) value in multiple tunnels. If two or more tunnels are configured to carry a given EXP value, CBTS picks one of those tunnels to carry this EXP value.

•The operation of CBTS is not supported with Any Transport over MPLS (AToM), MPLS TE Automesh, or label-controlled (LC)-ATM.

Information About MPLS Traffic Engineering (TE): Class-based Tunnel Selection

To configure the MPLS Traffic Engineering (TE): Class-based Tunnel Selection feature, you should understand the following concepts:

•Incoming Traffic Supported by MPLS TE Class-based Tunnel Selection

•CoS Attributes for MPLS TE Class-based Tunnel Selection

•Routing Protocols and MPLS TE Class-based Tunnel Selection

•Tunnel Selection with MPLS TE Class-based Tunnel Selection

•DS-TE Tunnels and MPLS TE Class-based Tunnel Selection

•Reoptimization and MPLS TE Class-based Tunnel Selection

•Interarea and Inter-AS and MPLS TE Class-based Tunnel Selection

•ATM PVCs and MPLS TE Class-based Tunnel Selection

Incoming Traffic Supported by MPLS TE Class-based Tunnel Selection

The CBTS feature supports the following kinds of incoming packets:

•At a provider edge (PE) router—Unlabeled packets that enter a Virtual Private Network (VPN) routing and forwarding (VRF) instance interface

•At a provider core (P) router—Unlabeled and MPLS-labeled packets that enter a non-VRF interface

•At a PE router in a Carrier Supporting Carrier (CSC) or interautonomous system (Inter-AS)—MPLS-labeled packets that enter a VRF interface

CoS Attributes for MPLS TE Class-based Tunnel Selection

CBTS supports tunnel selection based on the value of the EXP field that the headend router imposes on the packet. Before imposing this value, the router considers the input modular quality of service (QoS) command-line interface (CLI) (MQC). If the input MQC modifies the EXP field value, CBTS uses the modified value for its tunnel selection.

Packets may enter the headend from multiple incoming interfaces. These interfaces can come from different customers that have different DiffServ policies. In such cases, service providers generally use input MQC to apply their own DiffServ policies and mark imposed EXP values accordingly. Thus, CBTS can operate consistently for all customers by considering the EXP values marked by the service provider.

Note If the output MQC modifies the EXP field, CBTS ignores the change in the EXP value.

CBTS allows up to eight different tunnels on which it can distribute all classes of service.

Routing Protocols and MPLS TE Class-based Tunnel Selection

CBTS routes and forwards packets to MPLS TE tunnels for specified destinations through use of the following routing protocols:

•Intermediate System-to-Intermediate System (IS-IS) with Autoroute configured

•Open Shortest Path First (OSPF) with Autoroute configured

•Static routing

•Border Gateway Protocol (BGP) with recursion configured on the BGP next hop with packets forwarded on the tunnel through the use of IS-IS, OSPF, or static routing

Tunnel Selection with MPLS TE Class-based Tunnel Selection

This section contains the following topics related to tunnel selection:

•EXP Mapping Configuration

•Tunnel Selection for EXP Values

•Tunnel Failure Handling

•Misordering of Packets

EXP Mapping Configuration

With CBTS, you can configure each tunnel with any of the following:

•The same EXP information configured as it was before the CBTS feature was introduced, that is, with no EXP-related information

•One or more EXP values for the tunnel to carry

•A property that allows the carrying of all EXP values not currently allocated to any up-tunnel (default)

•One or more EXP values for the tunnel to carry, and the default property that allows the carrying of all EXP values not currently allocated to any up-tunnel

The default property (the carrying of all EXP values not currently allocated to any up-tunnel) effectively provides a way for the operator to avoid explicitly listing all possible EXP values. Even more important, the default property allows the operator to indicate tunnel preferences onto which to "bump" certain EXP values, should the tunnel carrying those EXP values go down. (See the tunnel mpls traffic-eng exp command for the command syntax.)

The configuration of each tunnel is independent of the configuration of any other tunnel. CBTS does not attempt to perform any consistency check for EXP configuration.

This feature allows configurations where:

•Not all EXP values are explicitly allocated to tunnels.

•Multiple tunnels have the default property.

•Some tunnels have EXP values configured and others do not have any values configured.

•A given EXP value is configured on multiple tunnels.

Tunnel Selection for EXP Values

This section contains information about the following topics:

•Tunnel Selection Process

•Tunnel Selection Examples

•Multipath with Non-TE Paths and MPLS TE Class-Based Tunnel Selection

•MPLS TE Class-Based Tunnel Selection and Policy-Based Routing

Tunnel Selection Process

Tunnel selection with this feature is a two-step process:

1. For a given prefix, routing (autoroute, static routes) occurs exactly as it did without the CBTS feature. The router selects the set of operating tunnels that have the best metrics, regardless of the EXP-related information configured on the tunnel.

2. CBTS maps all of the EXP values to the selected set of tunnels:

•If a given EXP value is configured:

–On only one of the tunnels in the selected set, CBTS maps the EXP value onto that tunnel.

–On two or more of the tunnels in the selected set, CBTS arbitrarily maps the EXP value onto one of these tunnels. First CBTS selects the tunnel on which the lowest EXP value is explicitly configured. Then CBTS picks the tunnel that has the lowest tunnel ID.

•If a given EXP value is not configured on any of the tunnels in the selected set:

–And only one of the tunnels in the selected set is configured as a default, CBTS maps the EXP value onto that tunnel.

–And two or more of the tunnels in the selected set are configured as defaults, CBTS arbitrarily maps the EXP value onto one of these tunnels.

–And no tunnel in the selected set of tunnels is configured as a default, CBTS does not map this EXP value onto any specific tunnel. Instead, CBTS performs CoS-unaware load balancing of that EXP information across all tunnels in the selected set.

CBTS relies on autoroute to select the tunnel bundle. Autoroute selects only tunnels that are on the SPF to the destination. Therefore, similar to Autoroute, CBTS does not introduce any risk of routing loops.

Tunnel Selection Examples

The following examples show various tunnel configurations that are set up by an operator and indicate how CBTS maps packets carrying EXP values onto these tunnels. Each example describes a different configuration: a default tunnel configured, more than one tunnel configured with the same EXP value, and so on.

Example 1—Default Tunnel Configured

An operator configures the following parameters on tunnels T1 and T2:

•T1: exp = 5, autoroute

•T2: exp = default, autoroute

If T1 and T2 are next-hop interfaces for prefix P, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1

•Packets with <Dest = P, exp = anything-other-than-5> onto T2

Example 2— EXP Values Configured on Two Tunnels; One Default Tunnel

An operator configures the following parameters on tunnels T1, T2, and T3:

•T1: exp = 5, autoroute

•T2: exp = 3 and 4, autoroute

•T3: exp = default, autoroute

If T1, T2, and T3 are next-hop interfaces for prefix P, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1

•Packets with <Dest = P, exp = 3 or 4> onto T2

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T3

Example 3—More than One Tunnel with the Same EXP

An operator configures the following parameters on tunnels T1, T2, and T3:

•T1: exp = 5, autoroute

•T2: exp = 5, autoroute

•T3: exp = default, autoroute

If T1, T2, and T3 are next-hop interfaces for prefix P, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1 (arbitrary selection)

•Packets with <Dest = P, exp = anything-other-than-5> onto T3

•No packets onto T2

Example 4—Static Route Configured

An operator configures the following parameters on tunnels T1 and T2:

•T1: exp = 5, autoroute

•T2: exp = 3

•Static route to P on T2

If prefix P is behind the T1 and T2 tailend router, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = anything> onto T2

•No packets onto T1

Static routes are preferred over dynamic routes; therefore, the router chooses only T2 as the "selected set" of tunnels.

Example 5—Metrics Configured on Tunnels

An operator configures the following parameters on tunnels T1 and T2:

•T1: exp = 5, autoroute, relative metric -2

•T2: exp = 3, autoroute, relative metric -3

CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = anything> onto T2

•No packets onto T1

The autoroute tunnel selection algorithm selects the tunnel with the best metric. Therefore, the router selects only T2 as the "selected set" of tunnels.

Example 6—No Default or Metric Configuration

An operator configures the following parameters on tunnels T1 and T2:

•T1: exp = 5, autoroute

•T2: exp = 3, autoroute

If T1 and T2 are the next-hop interfaces for prefix P, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1

•Packets with <Dest = P, exp = 3> onto T2

•Packets with <Dest = P, exp = anything-other-than-3-or-5> onto T2

If a packet arrives with an EXP value that is different from any value configured for a tunnel, the packet goes in to the default tunnel. If no default tunnel is configured, the packet goes in to the tunnel that is configured with the lowest EXP value.

Multipath with Non-TE Paths and MPLS TE Class-Based Tunnel Selection

For a given prefix in the routing process, the router might select a set of paths that includes both TE tunnels and non-TE-tunnel paths (SPF paths). For example, internal Border Gateway Protocol (iBGP) Multipath might be activated and result in multiple BGP next hops for that prefix, where one BGP next hop is reachable through TE tunnels and other BGP next hops are reachable through non-TE-tunnel paths.

An equal cost IGP path might also exist over TE tunnels and over a non-TE tunnel path. For example, a TE tunnel metric might be modified to be equal to the SPF path.

In these situations, CBTS maps traffic in the following manner:

•If a given EXP value is configured on one or more of the tunnels in the selected set, CBTS maps the EXP value onto that tunnel or one of those tunnels.

•If a given EXP value is not configured on any of the tunnels in the selected set but one or more of the tunnels is configured as a default in the selected set, then CBTS maps the EXP value onto that tunnel or one of those tunnels.

•If a given EXP value is not configured on any of the tunnels from the selected set and no tunnel in the selected set is configured as a default, CBTS performs CoS-unaware load-balancing of that EXP value across all the possible paths, including all of the TE tunnels of the selected set and the non-TE paths.

•If the routing process allocates all EXP values to tunnels or if a default is used, then routing does not use the non-TE paths unless all TE tunnels are down.

MPLS TE Class-Based Tunnel Selection and Policy-Based Routing

If you configure both policy-based routing (PBR) over TE tunnels (in non-VRF environments) and CBTS, the PBR decision overrides the CBTS decision. PBR is an input process that the router performs ahead of regular forwarding.

Tunnel Failure Handling

This section contains the following sections:

•Tunnel Up or Down

•Behavior When a Tunnel Goes Down

Tunnel Up or Down

For CBTS operation, the important question is whether the tunnel interface is up or down, not whether the current TE label switched path (LSP) is up or down. For example, a TE LSP might go down but is reestablished by the headend because another path option exists. The tunnel interface does not go down during the transient period while the TE LSP is reestablished. Because the tunnel interface does not go down, the corresponding EXP does not get rerouted onto another tunnel during the transient period.

Behavior When a Tunnel Goes Down

When a tunnel used by CBTS for forwarding goes down, the feature adjusts its tunnel selection for the affected EXP values. It reapplies the tunnel selection algorithm to define the behavior of packets for all EXP values, as shown in the examples that follow.

Example 1—Tunnel Other than the Default Tunnel Goes Down

An operator configures the following parameters on tunnels T1, T2, and T3:

•T1: exp = 5, autoroute

•T2: exp = 3 and 4, autoroute

•T3: exp = default, autoroute

If T1, T2, and T3 are next-hop interfaces for prefix P and Tunnel T1 goes down, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 3, 4> onto T2 (as before)

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T3 (as before)

•Packets with <Dest = P, exp = 5> onto T3

Example 2—Default Tunnel Goes Down

An operator configures the following parameters on tunnels T1, T2, and T3:

•T1: exp = 5, autoroute

•T2: exp = 3 and 4, autoroute

•T3: exp = default, autoroute

If T1, T2, and T3 are next-hop interfaces for prefix P and Tunnel T3 goes down, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1 (as before)

•Packets with <Dest = P, exp = 3, 4> onto T2 (as before)

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T1 and T2, following existing CoS-unaware load balancing

Example 3—Two Default Tunnels Are Configured

An operator configures the following parameters on tunnels T1, T2, and T3:

•T1: exp = 5, autoroute

•T2: exp = 3, 4, and default, autoroute

•T3: exp = 0, 1, 2, 6, 7, and default, autoroute

If T1, T2, and T3 are next-hop interfaces for prefix P and Tunnel T3 goes down, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1 (as before)

•Packets with <Dest = P, exp = 3, 4> onto T2 (as before)

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T2

If tunnel T2 goes down, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 5> onto T1 (as before)

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T3 (as before)

•Packets with <Dest = P, exp = 3, or 4> onto T3

If tunnel T1 goes down, CBTS maps the packets onto the tunnels in this way:

•Packets with <Dest = P, exp = 3, or 4> onto T2 (as before)

•Packets with <Dest = P, exp = 0, 1, 2, 6, or 7> onto T3 (as before)

•Packets with <Dest = P, exp = 5> onto either T2 or T3, but not both

In Example 3, the operator configures the EXP default option on two tunnels to ensure that nonvoice traffic is never redirected onto the voice tunnel (T1).

Misordering of Packets

In DiffServ, packets from a given flow might get marked with EXP values that are different from each other but belong to the same CoS value because of in-contract and out-of-contract marking of packets. We can refer to these values of EXP bits as EXP-in and EXP-out.

If packets for EXP-in are sent on a different tunnel than packets for EXP-out, then misordering of packets within the same flows could occur. For that reason, CBTS allows operators to ensure that EXP-in and EXP-out never get mapped onto different tunnels.

The CBTS feature allows the operator to configure EXP-in and EXP-out to be transported on the same tunnel when that tunnel is up. This ensures that the feature does not introduce misordering of packets. In case of tunnel failure, the tunnel selection algorithm ensures that if EXP-in and EXP-out were carried on the same tunnel before the failure, they are still carried on a single tunnel after the failure. Thus, CBTS protects against nontransient misordering even in the event of tunnel failure.

Note CBTS does not attempt to force EXP-in and EXP-out to be carried on the same tunnel. The operator must configure CBTS so that EXP-in and EXP-out are carried on the same tunnel. This is comparable to the regular DiffServ situation, where the operator must ensure that EXP-in and EXP-out are configured to go in the same queue.

Fast Reroute and MPLS TE Class-based Tunnel Selection

CBTS allows Fast Reroute (FRR) protection on tunnels for which you configure CoS-based selection.

CBTS operation with FRR does not change the number of or the way in which FRR backup tunnels might be used. The operation of FFR is the same as when CBTS is not activated. After you configure primary tunnels from a given headend to a given tailend, you can use FRR in the same way whether you activate CoS-based tunnel selection or not. This includes the following possibilities:

•None of the tunnels use FRR.

•All of the x tunnels are FRR-protected and share the same backup tunnel, if the traffic goes out the same interface.

•Some of the x tunnels are not FRR-protected; the remaining tunnels are FRR-protected and share the same backup tunnel, if the traffic goes out the same interface.

•Some of the x tunnels are not FRR-protected; the remaining tunnels are FRR-protected and are protected by different backup tunnels (for example, if the traffic goes out different interfaces, or if the traffic goes out the same interface). Bandwidth guarantees exist on the backup tunnels.

The important question for CBTS operation is only whether a tunnel interface goes down or stays up. FRR protects a given tunnel in exactly the same way as if CBTS were not configured on the tunnel.

DS-TE Tunnels and MPLS TE Class-based Tunnel Selection

CBTS operates over tunnels using DS-TE. Therefore, the tunnels on which CoS-based selection is performed can each arbitrarily and independently use a bandwidth from the global pool or the subpool.

Reoptimization and MPLS TE Class-based Tunnel Selection

CBTS allows tunnels on which CoS-based selection is performed to be reoptimized. Reoptimization does not affect CBTS operation.

Interarea and Inter-AS and MPLS TE Class-based Tunnel Selection

The CBTS operates over tunnels that are interarea when the interarea tunnels use static routes on destination prefixes or on the BGP next hops.

ATM PVCs and MPLS TE Class-based Tunnel Selection

CBTS operates over ATM permanent virtual circuits (PVCs). This means that TE or DS-TE tunnels handled by CBTS can span links that are ATM PVCs. ATM PVCs might be used on the headend router that is running CBTS and on transit label switch routers (LSRs).

How to Configure MPLS Traffic Engineering (TE): Class-based Tunnel Selection

This section contains the following procedures:

•Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend

•Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel

•Making the MPLS TE or DS-TE Tunnels Visible for Routing

•Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP

•Configuring a Master Tunnel

You need to configure the CBTS feature only on the tunnel headend. No CBTS configuration is required on the tailend or transit LSR.

Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend

Figure 1 shows an example of two tunnels, Tunnel 65 and Tunnel 66, transporting different classes of traffic between the same headend and the same tailend.

Figure 1 Tunnels Transporting Different Classes of Service Between the Same Headend and Tailend

To create multiple MPLS TE or DS-TE tunnels with the same headend and same tailend, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface tunnel number

4. ip unnumbered type number

5. tunnel destination {hostname | ip-address}

6. tunnel mode mpls traffic-eng

7. tunnel mpls traffic-eng bandwidth [sub-pool | global] bandwidth

8. exit

9. Repeat steps 3 through 8 on the same headend router to create additional tunnels from this headend to the same tailend.

10. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface tunnel number

Example:

Router(config)# interface tunnel 65

Configures an interface type and enters interface configuration mode.

Step 4 

ip unnumbered type number

Example:

Router(config-if)# ip unnumbered loopback0

Enables IP processing on an interface without assigning an explicit IP address to the interface.

Step 5 

tunnel destination {hostname | ip-address}

Example:

Router(config-if)# tunnel destination 10.10.10.12

Specifies the destination of the tunnel for this path option.

Step 6 

tunnel mode mpls traffic-eng

Example:

Router(config-if)# tunnel mode mpls traffic-eng

Sets the mode of a tunnel to MPLS for TE.

Step 7 

tunnel mpls traffic-eng bandwidth [sub-pool | global] bandwidth

Example:

Router(config-if)# tunnel mpls traffic-eng bandwidth sub-pool 3000

Configures the bandwidth for the MPLS TE tunnel. If automatic bandwidth is configured for the tunnel, use the tunnel mpls traffic-eng bandwidth command to configure the initial tunnel bandwidth, which is adjusted by the autobandwidth mechanism.

Note You can configure any existing MPLS TE command on these TE or DS-TE tunnels.

Step 8 

exit

Example:

Router(config-if)# exit

Returns to global configuration mode.

Step 9 

Repeat steps 3 through 8 on the same headend router to create additional tunnels from this headend to the same tailend.

—

Step 10 

end

Example:

Router(config)# end

Returns to privileged EXEC mode.

Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel

To configure EXP values to be carried by each MPLS TE or DS-TE tunnel, perform the following steps.

For each tunnel that you create, you must indicate which EXP values the tunnel carries.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. tunnel mpls traffic-eng exp [list-of-exp-values] [default]

5. exit

6. Repeat steps 3 through 5 for all MPLS TE tunnels that you created in the "Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend" section.

7. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface tunnel65

Configures an interface type and enters interface configuration mode.

Step 4 

tunnel mpls traffic-eng exp [list-of-exp-values] [default]

Example:

Router(config-if)# tunnel mpls traffic-eng exp 5

Specifies the EXP bits that will be forwarded over a member tunnel that is part of the CBTS bundle.

Step 5 

exit

Example:

Router(config-if)# exit

Returns to global configuration mode.

Step 6 

Repeat steps 3 through 5 for all MPLS TE tunnels that you created in the "Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend" section.

—

Step 7 

end

Example:

Router(config-if)# end

Returns to privileged EXEC mode.

Making the MPLS TE or DS-TE Tunnels Visible for Routing

Perform the following task to make the MPLS TE or DS-TE tunnels visible for routing.

Note Alternatively, static routing could be used instead of autoroute to make the TE or DS-TE tunnels visible for routing.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface type number

4. tunnel mpls traffic-eng autoroute announce

5. tunnel mpls traffic-eng autoroute metric {absolute | relative} value

6. end

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface type number

Example:

Router(config)# interface tunnel 65

Configures an interface type and enters interface configuration mode.

Step 4 

tunnel mpls traffic-eng autoroute announce

Example:

Router(config-if)# tunnel mpls traffic-eng autoroute announce

Specifies that the Interior Gateway Protocol (IGP) should use the tunnel (if the tunnel is up) in its enhanced SPF calculation.

Step 5 

tunnel mpls traffic-eng autoroute metric {absolute | relative} value

Example:

Router(config-if)# tunnel mpls traffic-eng autoroute metric relative 2


Specifies the MPLS TE tunnel metric that the IGP enhanced SPF calculation uses.

Note Even though the value for a relative metric can be from -10 to +10, configuring a tunnel metric with a negative value is considered a misconfiguration. If the metric to the tunnel tailend appears to be 4 from the routing table, then the cost to the tunnel tailend router is actually 3 because 1 is added to the cost for getting to the loopback address. In this instance, the lowest value that you can configure for the relative metric is -3.

Step 6 

end

Example:

Router(config-if)# end

Returns to privileged EXEC mode.

Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP

To verify that the MPLS TE or DS-TE tunnels are operating and announced to the IGP, perform the following steps.

SUMMARY STEPS

1. show mpls traffic-eng topology {A.B.C.D | igp-id {isis nsap-address | ospf A.B.C.D} [brief]

2. show mpls traffic-eng tunnels number [brief] protect

3. show ip cef [vrf vrf-name] [unresolved [detail] | [detail | summary]]

4. show mpls forwarding-table [network {mask | length} | labels label [- label] | interface interface | next-hop address | lsp-tunnel [tunnel-id]] [vrf vrf-name] [detail]

5. show mpls traffic-eng autoroute

DETAILED STEPS

Step 1 show mpls traffic-eng topology {A.B.C.D | igp-id {isis nsap-address | ospf A.B.C.D} [brief]

Use this command to display the MPLS TE global topology currently known at this node: 

Router# show mpls traffic-eng topology


My_System_id: 0000.0025.0003.00

IGP Id: 0000.0024.0004.00, MPLS TE Id:172.16.4.4 Router Node

      link[0 ]:Intf Address: 10.1.1.4

                  Nbr IGP Id: 0000.0024.0004.02, 

                admin_weight:10, affinity_bits:0x0

                max_link_bw:10000 max_link_reservable: 10000

	 	globalpool	subpool

               	total allocated	reservable 		reservable

               	--------------- 	---------- 	----------

	bw[0]: 	0 	1000	500

	bw[1]:	10 	990	490

	bw[2]: 	600 	390	390

	bw[3]: 	0 	390	390

	bw[4]: 	0 	390	390

	bw[5]: 	0 	390	390


Step 2 show mpls traffic-eng tunnels number [brief] [protection]

Use this command to display information for a specified tunneling interface: 

Router# show mpls traffic-eng tunnels 500 brief protection 


Router#_t500

  LSP Head, Tunnel500, Admin: up, Oper: up

  Src 172.16.0.5, Dest 172.16.0.8, Instance 17

  Fast Reroute Protection: None

  Path Protection: 1 Common Link(s) , 1 Common Node(s)

    Primary lsp path:192.168.6.6 192.168.7.7

                     192.168.8.8 192.168.0.8


    Protect lsp path:172.16.7.7 192.168.8.8

                     10.0.0.8

    Path Protect Parameters:

      Bandwidth: 50       kbps (Global)  Priority: 7  7   Affinity: 0x0/0xFFFF

      Metric Type: TE (default)

    InLabel  :  -

    OutLabel : Serial5/3, 46

    RSVP Signalling Info:

         Src 172.16.0.5, Dst 172.16.0.8, Tun_Id 500, Tun_Instance 18

      RSVP Path Info:

        My Address: 172.16.0.5

        Explicit Route: 192.168.7.7 192.168.8.8

        Record   Route:   NONE

        Tspec: ave rate=50 kbits, burst=1000 bytes, peak rate=50 kbits

      RSVP Resv Info:

        Record   Route:   NONE

        Fspec: ave rate=50 kbits, burst=1000 bytes, peak rate=50 kbits

Step 3 show ip cef summary

Use this command to display a summary of the IP CEF table: 

Router# show ip cef summary


IP Distributed CEF with switching (Table Version 25), flags=0x0

 21 routes, 0 reresolve, 0 unresolved (0 old, 0 new), peak 1

 21 leaves, 16 nodes, 19496 bytes, 36 inserts, 15 invalidations

 0 load sharing elements, 0 bytes, 0 references

 universal per-destination load sharing algorithm, id 5163EC15

 3(0) CEF resets, 0 revisions of existing leaves

 Resolution Timer: Exponential (currently 1s, peak 1s)

 0 in-place/0 aborted modifications

 refcounts:  4377 leaf, 4352 node


 Table epoch: 0 (21 entries at this epoch)


 Adjacency Table has 9 adjacencies

Step 4 show mpls forwarding-table [network {mask | length} | labels label [- label] | interface interface | next-hop address | lsp-tunnel [tunnel-id]] [vrf vrf-name] [detail]

Use this command to display the contents of the MPLS Label Forwarding Information Base (LFIB): 

Router# show mpls forwarding-table


Local Outgoing      Prefix            Bytes tag Outgoing       Next Hop       

Label Label or VC   or Tunnel Id      switched  interface                     

26    No Label      10.253.0.0/16     0         Et4/0/0       10.27.32.4    

28    1/33          10.15.0.0/16      0         AT0/0.1       point2point    

29    Pop Label     10.91.0.0/16      0         Hs5/0         point2point    

      1/36          10.91.0.0/16      0         AT0/0.1       point2point    

30    32            10.250.0.97/32    0         Et4/0/2       10.92.0.7      

      32            10.250.0.97/32    0         Hs5/0         point2point    

34    26            10.77.0.0/24      0         Et4/0/2       10.92.0.7      

      26            10.77.0.0/24      0         Hs5/0         point2point    

35    No Label[T]   10.100.100.101/32 0         Tu301         point2point    

36    Pop Label     10.1.0.0/16      0         Hs5/0         point2point    

      1/37          10.1.0.0/16      0         AT0/0.1       point2point    


[T]     Forwarding through a TSP tunnel.

        View additional tagging info with the 'detail' option

Step 5 show mpls traffic-eng autoroute

Use this command to display tunnels that are announced to the IGP, including interface, destination, and bandwidth: 

Router# show mpls traffic-eng autoroute


MPLS TE autorouting enabled

  destination 0002.0002.0002.00 has 2 tunnels

    Tunnel1021 (traffic share 10000, nexthop 10.2.2.2, absolute metric 11)

    Tunnel1022 (traffic share 3333, nexthop 10.2.2.2, relative metric -3)

  destination 0003.0003.0003.00 has 2 tunnels

    Tunnel1032 (traffic share 10000, nexthop 172.16.3.3)

    Tunnel1031 (traffic share 10000, nexthop 172.16.3.3, relative metric -1)

Configuring a Master Tunnel

To configure a master tunnel to which other tunnels can be members, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. interface tunnel number

4. ip unnumbered type number

5. tunnel destination {hostname | ip-address}

6. tunnel mode mpls traffic-eng

7. tunnel mpls traffic-eng exp-bundle master

8. tunnel mpls traffic-eng exp-bundle member tunnel-number

9. exit

DETAILED STEPS

 
Command or Action
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

•Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

interface tunnel number

Example:

Router(config)# interface tunnel 65

Configures an interface type and enters interface configuration mode.

Step 4 

ip unnumbered type number

Example:

Router(config-if)# ip unnumbered loopback0

Enables IP processing on an interface without assigning an explicit IP address to the interface.

Step 5 

tunnel destination {hostname | ip-address}

Example:

Router(config-if)# tunnel destination 10.10.10.12

Specifies the destination of the tunnel for this path option.

Step 6 

tunnel mode mpls traffic-eng

Example:

Router(config-if)# tunnel mode mpls traffic-eng

Sets the mode of a tunnel to MPLS for TE.

Step 7 

tunnel mpls traffic-eng exp-bundle master

Example:

Router(config-if)# tunnel mpls traffic-eng exp-bundle master

Configures a master tunnel.

Step 8 

tunnel mpls traffic-eng exp-bundle member tun- nel-number

Example:

Router(config-if)# tunnel mpls traffic-eng exp-bundle member tunnel1

Identifies which tunnel is a member of a master tunnel.

Step 9 

exit

Example:

Router(config-if)# exit

Exits to global configuration mode.

Configuration Examples for MPLS Traffic Engineering (TE): Class-based Tunnel Selection

This section contains the following configuration examples:

•Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend: Example

•Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel: Example

•Making the MPLS TE or DS-TE Tunnels Visible for Routing: Example

•Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP: Example

•Configuring a Master Tunnel: Example

Creating Multiple MPLS TE or DS-TE Tunnels from the Same Headend to the Same Tailend: Example

The following example shows how to create multiple MPLS TE or DS-TE tunnels from the same headend to the same tailend: 

Router(config)# interface Tunnel 65 

Router(config-if)# ip numbered loopback0

Router(config-if)# tunnel destination 10.1.1.1 

Router(config-if)# tunnel mode mpls traffic-eng

Router(config-if)# tunnel mpls traffic-eng bandwidth sub-pool 30000 

Router(config-if)# ^Z

Router(config)# interface Tunnel 66 

Router(config-if)# ip numbered loopback0

Router(config-if)# tunnel destination 10.1.1.1 

Router(config-if)# tunnel mode mpls traffic-eng

Router(config-if)# tunnel mpls traffic-eng bandwidth 50000

Router(config-if)# end

Router#

Configuring EXP Values to Be Carried by Each MPLS TE or DS-TE Tunnel: Example

The following example shows how to configure EXP values to be carried by each MPLS TE or DS-TE tunnel that you created: 

Router(config)# interface Tunnel 65 

Router(config-if)# tunnel mpls traffic-eng exp 5

Router(config-if)# ^Z

Router(config)# 

Router(config)# interface Tunnel 66 

Router(config-if)# tunnel mpls traffic-eng exp 0 1 2 3 4 6 7

Router(config-if)# end

Router#

Making the MPLS TE or DS-TE Tunnels Visible for Routing: Example

The following example shows how to make the MPLS TE or DS-TE tunnels visible for routing: 

Router(config)# interface Tunnel 65 

Router(config-if)# tunnel mpls traffic-eng autoroute announce

Router(config-if)# tunnel mpls traffic-eng autoroute metric relative -2

Router(config-if)# ^Z

Router(config)# 

Router(config)# interface Tunnel 66 

Router(config-if)# tunnel mpls traffic-eng autoroute announce

Router(config-if)# tunnel mpls traffic-eng autoroute metric relative -2

Router(config-if)# end

Router#

Packets destined beyond 10.1.1.1 are sent on:

•Tunnel 65 if their EXP value after input MQC is 5.

•Tunnel 66 if their EXP value after input MQC is 0, 1, 2, 3, 4, 6, or 7.

Verifying That the MPLS TE or DS-TE Tunnels Are Operating and Announced to the IGP: Example

The output for each of the following examples helps verify that the MPLS TE or DS-TE tunnels are operating and visible.

The show mpls traffic-eng topology command output displays the MPLS TE global topology: 

Router# show mpls traffic-eng topology 10.0.0.1


IGP Id: 10.0.0.1, MPLS TE Id:10.0.0.1 Router Node  (ospf 10  area 0) id 1

      link[0]: Broadcast, DR: 10.0.1.2, nbr_node_id:6, gen:18

	  frag_id 0, Intf Address:10.1.1.1

	  TE metric:1, IGP metric:1, attribute_flags:0x0

	  SRLGs: None 

	  physical_bw: 100000 (kbps), max_reservable_bw_global: 1000 (kbps)

	  max_reservable_bw_sub: 0 (kbps)


	                         Global Pool       Sub Pool

	       Total Allocated   Reservable        Reservable

	       BW (kbps)         BW (kbps)         BW (kbps)

	       ---------------   -----------       ----------

	bw[0]:            0             1000                0

	bw[1]:            0             1000                0

	bw[2]:            0             1000                0

	bw[3]:            0             1000                0

	bw[4]:            0             1000                0

	bw[5]:            0             1000                0

	bw[6]:            0             1000                0

	bw[7]:          100              900                0


      link[1]: Broadcast, DR: 10.0.2.2, nbr_node_id:7, gen:19

	  frag_id 1, Intf Address:10.0.2.1

	  TE metric:1, IGP metric:1, attribute_flags:0x0

	  SRLGs: None 

	  physical_bw: 100000 (kbps), max_reservable_bw_global: 1000 (kbps)

	  max_reservable_bw_sub: 0 (kbps)


	                         Global Pool       Sub Pool

	       Total Allocated   Reservable        Reservable

	       BW (kbps)         BW (kbps)         BW (kbps)

	       ---------------   -----------       ----------

	bw[0]:            0             1000                0

	bw[1]:            0             1000                0

	bw[2]:            0             1000                0

	bw[3]:            0             1000                0

	bw[4]:            0             1000                0

	bw[5]:            0             1000                0

	bw[6]:            0             1000                0

	bw[7]:          300              700                0

Router#


Router# show mpls traffic-eng topology 10.0.0.9


IGP Id: 10.0.0.9, MPLS TE Id:10.0.0.9 Router Node  (ospf 1