MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels
First Published: February 28, 2006
Last Updated: May 4, 2009
The MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels feature allows you to automatically adjust the bandwidth allocation for traffic engineering tunnels based on the tunnel's measured traffic load. The configured bandwidth in the running configuration is changed due to the automatic bandwidth behavior.
Finding Feature Information
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 for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE 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 TE—Automatic Bandwidth Adjustment for TE Tunnels
•Restrictions for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•Information About MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•How to Configure MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•Configuration Examples for MPLS TE—Automatic Bandwidth Adjustments for TE Tunnels
•Additional References
•Feature Information for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
Prerequisites for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
Your network must support the following Cisco IOS XE features before configure the MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels feature:
•Multiprotocol Label Switching (MPLS) traffic engineering tunnels
•Cisco Express Forwarding
•Intermediate System-to-Intermediate System (IS-IS) or Open Shortest Path First (OSPF)
Restrictions for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•The automatic bandwidth adjustment feature treats each tunnel for which it has been enabled independently. That is, it adjusts the bandwidth for each such tunnel according to the adjustment frequency configured for the tunnel and the sampled output rate for the tunnel since the last adjustment without regard for any adjustments previously made or pending for other tunnels.
•If a tunnel is brought down to calculate a new label switched path (LSP) because the LSP is not operational, the configured bandwidth is not saved. If the router is reloaded, the last saved automatic bandwidth value is used.
•You cannot configure MPLS TE over the logical generic routing encapsulation (GRE) tunnel interface.
•MPLS traffic engineering supports only a single IGP process/instance. Multiple IGP processes/instances are not supported and MPLS traffic engineering should not be configured in more than one IGP process/instance.
Information About MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels Overview
•MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels Benefits
MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels Overview
Traffic engineering autobandwidth samples the average output rate for each tunnel marked for automatic bandwidth adjustment. For each marked tunnel, the feature periodically (for example, once per day) adjusts the tunnel's allocated bandwidth to be the largest sample for the tunnel since the last adjustment.
The frequency with which tunnel bandwidth is adjusted and the allowable range of adjustments is configurable on a per-tunnel basis. In addition, the sampling interval and the interval over which to average tunnel traffic to obtain the average output rate is user-configurable on a per-tunnel basis.
MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels Benefits
The automatic bandwidth feature makes it easy to configure and monitor the bandwidth for MPLS TE tunnels. If automatic bandwidth is configured for a tunnel, TE automatically adjusts the tunnel's bandwidth.
How to Configure MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
•Configuring a Platform to Support Traffic Engineering Tunnels (required)
•Configuring IS-IS for MPLS Traffic Engineering (required)
•Configuring an MPLS Traffic Engineering Tunnel (required)
•Configuring Bandwidth on Each Link That the Tunnels Cross (required)
•Configuring a Platform to Support Automatic Bandwidth Adjustment (required)
•Configuring Automatic Bandwidth Adjustment for a Tunnel (required)
•Configuring the Interval for Computing Tunnel Average Output Rate (optional)
•Verifying the Automatic Bandwidth Configuration
Configuring a Platform to Support Traffic Engineering Tunnels
SUMMARY STEPS
1. enable
2. configure terminal
3. ip cef distributed
4. mpls traffic-eng tunnels
5. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
ip cef distributed
Router(config)# ip cef distributed |
Enables distributed Cisco Express Forwarding operation. |
Step 4 |
mpls traffic-eng tunnels
Router(config)# mpls traffic-eng tunnels |
Enables the MPLS traffic engineering tunnel feature on a device. |
Step 5 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring IS-IS for MPLS Traffic Engineering
Note MPLS traffic engineering supports only a single IGP process/instance. Multiple IGP processes/instances are not supported and MPLS traffic engineering should not be configured in more than one IGP process/instance.
SUMMARY STEPS
1. enable
2. configure terminal
3. router isis
4. mpls traffic-eng level-1
5. mpls traffic-eng router-id loopback0
6. metric-style wide
7. exit
8. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
router isis
Router(config)# router isis |
Enables IS-IS routing and specifies an IS-IS process for IP. This command places you in router configuration mode. |
Step 4 |
mpls traffic-eng level-1
Router(config-router)# mpls traffic-eng level-1 |
Turns on MPLS traffic engineering for IS-IS level 1. |
Step 5 |
mpls traffic-eng router-id loopback0
Router(config-router)# mpls traffic-eng router-id loopback0 |
Specifies that the traffic engineering router identifier for the node is the IP address associated with interface loopback0. |
Step 6 |
metric-style wide
Router(config-router)# metric-style wide |
Configures a router to generate and accept only new-style type, length, value objects (TLVs). |
Step 7 |
exit
Router(config-router)# exit |
Exits to global configuration mode. |
Step 8 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring OSPF for MPLS Traffic Engineering
Note MPLS traffic engineering supports only a single IGP process/instance. Multiple IGP processes/instances are not supported and MPLS traffic engineering should not be configured in more than one IGP process/instance.
SUMMARY STEPS
1. enable
2. configure terminal
3. router ospf process-id
4. mpls traffic-eng area number
5. mpls traffic-eng router-id loopback0
6. exit
7. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
router ospf process-id
Router(config)# router ospf 200 |
Configures an OSPF routing process for IP and enters router configuration mode. •The process-id is an internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. Assign a unique value for each OSPF routing process. |
Step 4 |
mpls traffic-eng area number
Router(config-router)# mpls traffic-eng area 0 |
Turns on MPLS traffic engineering for the indicated OSPF area. |
Step 5 |
mpls traffic-eng router-id loopback0
Router(config-router)# mpls traffic-eng router-id loopback0 |
Specifies that the traffic engineering router identifier for the node is the IP address associated with interface loopback0. |
Step 6 |
exit
Router(config-router)# exit |
Exits to global configuration mode. |
Step 7 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring an MPLS Traffic Engineering Tunnel
The MPLS TE tunnel has two path setup options: a preferred explicit path and a backup dynamic path.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface tunnel number
4. ip unnumbered interface-type interface-number
5. tunnel destination ip-address
6. tunnel mode mpls traffic-eng
7. tunnel mpls traffic-eng bandwidth bandwidth
8. tunnel mpls traffic-eng path-option [protect] number {dynamic | explicit
{name path-name | identifier path-number}} [lockdown]
9. exit
10. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
interface tunnel number
Router(config)# interface tunnel 1 |
Configures a tunnel interface and enters interface configuration mode. |
Step 4 |
ip unnumbered interface-type interface-number
Router(config-if)# ip unnumbered loopback 0 |
Gives the tunnel interface an IP address that is the same as that of interface Loopback0. •An MPLS traffic engineering tunnel interface should be unnumbered because it represents a unidirectional link. Note This command is not effective until Lookback0 has been configured with an IP address. |
Step 5 |
tunnel destination ip-address
Router(config-if)# tunnel destination 10.3.3.3 |
Specifies the destination for a tunnel. The destination must be the MPLS traffic engineering router ID of the destination device. |
Step 6 |
tunnel mode mpls traffic-eng
Router(config-if)# tunnel mode mpls traffic-eng |
Sets the encapsulation mode of the tunnel to MPLS traffic engineering. |
Step 7 |
tunnel mpls traffic-eng bandwidth bandwidth
Router(config-if)# tunnel mpls traffic-eng bandwidth 250 |
Configures the bandwidth for the MPLS traffic engineering tunnel. •The bandwidth argument is the bandwidth, in kilobits per second, set aside for the MPLS traffic engineering tunnel. Range is from 1 to 4294967295. The default is 0. •If automatic bandwidth is configured for the tunnel, the tunnel mpls traffic-eng bandwidth command configures the initial tunnel bandwidth, which will be adjusted by the autobandwidth mechanism. Note If you configure a tunnel's bandwidth with the tunnel mpls traffic-eng bandwidth command and the minimum amount of automatic bandwidth with the tunnel mpls traffic-eng auto-bw command, the minimum amount of automatic bandwidth adjustment is the lower of those two configured values. |
Step 8 |
tunnel mpls traffic-eng path-option [protect] number {dynamic | explicit {name path-name | identifier path-number}}[lockdown]
Router(config-if)# tunnel mpls traffic-eng path-option 10 explicit avoid-protected-link |
Configures the tunnel to use a named IP explicit path or a path dynamically calculated from the traffic engineering topology database. •A dynamic path is used if an explicit path is currently unavailable. |
Step 9 |
exit
Router(config-if)# exit |
Exits to global configuration mode. |
Step 10 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Troubleshooting Tips
Each tunnel mpls traffic-eng auto-bw command supersedes the previous one. Therefore, if you want to specify multiple options for a tunnel, you must specify them all in a single tunnel mpls traffic-eng auto-bw command.
Configuring Bandwidth on Each Link That the Tunnels Cross
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type slot/subslot/port[.subinterface-number]
4. mpls traffic-eng tunnels
5. ip rsvp bandwidth [interface-kbps] [single-flow-kbps] [sub-pool kbps]
6. exit
7. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
interface type slot/subslot/port[.subinterface-number]
Router(config)# interface FastEthernet0/0/0 |
Configures an interface type and enters interface configuration mode |
Step 4 |
mpls traffic-eng tunnels
Router(config-if)# mpls traffic-eng tunnels |
Enables MPLS traffic engineering tunnels on an interface. |
Step 5 |
ip rsvp bandwidth [interface-kbps] [single-flow-kbps] [sub-pool kbps]
Router(config-if)# ip rsvp bandwidth 1000 100 |
Enables Resource reservation Protocol (RSVP) for IP on an interface. •The interface-kbps argument specifies the maximum amount of bandwidth (in kbps) that may be allocated by RSVP flows. The range is from 1 to 10,000,000. •The single-flow-kbps argument is the maximum amount of bandwidth, in kbps, that may be allocated to a single flow. The range is from 1 to 10,000,000. |
Step 6 |
exit
Router(config-if)# exit |
Exits to global configuration mode. |
Step 7 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring a Platform to Support Automatic Bandwidth Adjustment
To enable automatic bandwidth adjustment on a platform and initiate sampling the output rate for tunnels configured for bandwidth adjustment, perform the following task.
SUMMARY STEPS
1. enable
2. configure terminal
3. mpls traffic-eng auto-bw timers [frequency seconds]
4. no mpls traffic-eng auto-bw timers
5. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
mpls traffic-eng auto-bw timers [frequency seconds]
Router(config)# mpls traffic-eng auto-bw timers frequency 300 |
Enables automatic bandwidth adjustment on a platform and begins sampling the output rate for tunnels that have been configured for automatic bandwidth adjustment. •The frequency keyword specifies the interval, in seconds, for sampling the output rate of each tunnel configured for automatic bandwidth. The range is 1 through 604800. The recommended value is 300. |
Step 4 |
no mpls traffic-eng auto-bw timers
Router(config)# no mpls traffic-eng auto-bw timers |
(Optional) Disables automatic bandwidth adjustment on a platform. •Use the no version of the command, which terminates output rate sampling and the bandwidth adjustment for tunnels. In addition, the no form of the command restores the configured bandwidth for each tunnel where configured bandwidth is determined as follows: –If the tunnel bandwidth was explicitly configured via the tunnel mpls traffic-eng bandwidth command after the running configuration was written (if at all) to the startup configuration, the "configured bandwidth" is the bandwidth specified by that command. –Otherwise, the configured bandwidth is the bandwidth specified for the tunnel in the startup configuration. |
Step 5 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring Automatic Bandwidth Adjustment for a Tunnel
To enable automatic bandwidth adjustment for a tunnel and constrain the range of automatic bandwidth adjustments applied to the tunnel, perform the following task.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface tunnel number
4. tunnel mpls traffic-eng auto-bw [max-bw number] [min-bw number]
5. exit
6. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
interface tunnel number
Router(config)# interface tunnel 1 |
Configures a tunnel interface and enters interface configuration mode. |
Step 4 |
tunnel mpls traffic-eng auto-bw [max-bw number] [min-bw number]
Router(config-if)# tunnel mpls traffic-eng auto-bw max-bw 2000 min-bw 1000 |
Enables automatic bandwidth adjustment for the tunnel. •The max-bw keyword specifies the maximum automatic bandwidth, in kbps, for this tunnel. The range is from 0 to 4294967295. •The min-bw keyword specifies the minimum automatic bandwidth, in kbps, for this tunnel. The range is from 0 to 4294967295. |
Step 5 |
exit
Router(config-if)# exit |
Exits to global configuration mode. |
Step 6 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Configuring the Interval for Computing Tunnel Average Output Rate
To specify the interval for computing the average output rate for an MPLS traffic engineering tunnel, perform the following task.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface tunnel number
4. load-interval seconds
5. exit
6. exit
DETAILED STEPS
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
interface tunnel number
Router(config)# interface tunnel 1 |
Configures a tunnel interface and enters interface configuration mode. |
Step 4 |
load-interval seconds
Router(config-if)# load-interval 90 |
Configures the interval over which the input and output rates for the interface are averaged. •The seconds argument is the length of time for which data is used to compute load statistics. The value is a multiple of 30, from 30 to 600 (30, 60, 90, 120, and so on). The default is 300 seconds. |
Step 5 |
exit
Router(config-if)# exit |
Exits to global configuration mode. |
Step 6 |
exit
Router(config)# exit |
Exits to privileged EXEC mode. |
Verifying the Automatic Bandwidth Configuration
SUMMARY STEPS
1. enable
2. show mpls traffic-eng tunnels
3. show running-config
4. exit
DETAILED STEPS
Step 1 enable
Use this command to enter privileged EXEC mode. Enter you password if prompted. For example:
Step 2 show mpls traffic-eng tunnels
Use this command to show information about tunnels, including automatic bandwidth information for tunnels that have the feature enabled. For example:
Router# show mpls traffic-eng tunnels
Name:tagsw4500-9_t1 (Tunnel1) Destination:10.0.0.11
Admin:up Oper:up Path:valid Signalling:connected
path option 1, type explicit pbr_south (Basis for Setup, path weight 30)
path option 2, type dynamic
Bandwidth:5000 kbps (Global) Priority:7 7 Affinity:0x0/0xFFFF
AutoRoute: disabled LockDown:disabled Loadshare:5000 bw-based
auto-bw:(86400/85477) 5347 Bandwidth Requested:5000
In the command output:
•The auto-bw line indicates that automatic bandwidth adjustment is enabled for the tunnel.
•86400 is the time, in seconds, between bandwidth adjustments.
•85477 is the time, in seconds, remaining until the next bandwidth adjustment.
•5347 is the largest bandwidth sample since the last bandwidth adjustment.
•5000 is the last bandwidth adjustment and the bandwidth currently requested for the tunnel.
Step 3 show running-config
Use this command to verify that the MPLS TE automatic bandwidth command is as you expected. For example:
Router# show running-config
tunnel destination 192.168.17.17 255.255.255.0
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng bandwidth 1500
tunnel mpls traffic-eng priority 1 1
tunnel mpls traffic-eng path-option 1 dynamic
tunnel mpls traffic-eng auto bw max-bw 2000 min-bw 1000 !Enable automatic bandwidth
The sample output from the show running-config command shows that the value 1500, in the tunnel mpls traffic-eng bandwidth 1500 command, changes after an adjustment is made.
Step 4 exit
Use this command to exit to user EXEC mode. For example:
Configuration Examples for MPLS TE—Automatic Bandwidth Adjustments for TE Tunnels
Figure 1 illustrates a sample MPLS topology. The following sections contain sample configuration examples to configure automatic bandwidth adjustment for MPLS traffic engineering tunnels originating on Router 1 and to enable automatic bandwidth adjustment for Tunnel1.
Figure 1 Sample MPLS Traffic Engineering Tunnel Configuration
This section provides the following configuration examples based on Figure 1:
•Example: Configuring MPLS Traffic Engineering Automatic Bandwidth
•Example: Tunnel Configuration for Automatic Bandwidth
The examples omit some configuration required for MPLS traffic engineering, such as the required RSVP and Interior Gateway Protocol (IGP) (IS-IS or OSPF) configuration, because the purpose of these examples is to illustrate the configuration for automatic bandwidth adjustment.
Example: Configuring MPLS Traffic Engineering Automatic Bandwidth
The following example shows how to use the mpls traffic-eng auto-bw timers command to enable automatic bandwidth adjustment for Router 1. The command specifies that the output rate is to be sampled every 10 minutes for tunnels configured for automatic bandwidth adjustment.
mpls traffic-eng auto-bw timers frequency 600 !Enable automatic bandwidth adjustment
ip address 192.168.11.11 255.255.255.0
Example: Tunnel Configuration for Automatic Bandwidth
The following example shows how to use the tunnel mpls traffic-eng auto-bw command to enable automatic bandwidth adjustment for Tunnel1. The command specifies a maximum allowable bandwidth of 2000 kbps, a minimum allowable bandwidth of 1000 kbps, and that the default automatic bandwidth adjustment frequency of once a day be used.
tunnel destination 192.168.17.17 255.255.255.0
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng bandwidth 1500
tunnel mpls traffic-eng priority 1 1
tunnel mpls traffic-eng path-option 1 dynamic
tunnel mpls traffic-eng auto bw max-bw 2000 min-bw 1000 !Enable automatic bandwidth
Additional References
Related Documents
Standards
|
|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
— |
MIBs
|
|
MPLS Traffic Engineering MIB |
To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs |
RFCs
|
|
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified. |
— |
Technical Assistance
|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
http://www.cisco.com/cisco/web/support/index.html |
Feature Information for MPLS TE—Automatic Bandwidth Adjustment for TE Tunnels
Table 1 lists the features in this module and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 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.
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)
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.
© 2006-2011 Cisco Systems, Inc. All rights reserved.