MPLS Traffic Engineering: Tunnel Source


First Published: May 15, 2009
Last Updated: June 11, 2010

The Multiprotocol Label Switching (MPLS) Traffic Engineering (TE): Tunnel Source feature allows you to specify the IP address assigned to an interface as the source IP address for control packets. The default behavior is to use the router ID configured in the Interior Gateway Protocol (IGP) using the mpls traffic-eng router-id command.

Finding Feature Information

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 for MPLS Traffic Engineering: Tunnel Source" section.

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.

Contents

Prerequisites for MPLS Traffic Engineering: Tunnel Source

Restrictions for MPLS Traffic Engineering: Tunnel Source

Information About MPLS Traffic Engineering: Tunnel Source

How to Configure MPLS Traffic Engineering: Tunnel Source

Configuration Examples for MPLS Traffic Engineering: Tunnel Source

Additional References

Feature Information for MPLS Traffic Engineering: Tunnel Source

Prerequisites for MPLS Traffic Engineering: Tunnel Source

You can configure tunnel source only for MPLS-TE tunnels.

Understand how to configure TE tunnels. See the "Additional References" section.

Restrictions for MPLS Traffic Engineering: Tunnel Source

The configuration of other types of tunnels are not affected by this feature.

Configuring a tunnel source affects the control traffic and not the traffic forwarded in the dataplane on this tunnel.

Information About MPLS Traffic Engineering: Tunnel Source

When you configure an MPLS TE tunnel, the address specified in the tunnel source command is used as the source IP address for control traffic to signal the tunnel. The source IP address overrides the default IP address taken from the IGP command mpls traffic-eng router-id.

MPLS Traffic Engineering: Tunnel Source Usage Guidelines

Specifying a new source for an established tunnel causes the tunnel to be withdrawn and re-established.

The tunnel source may be configured as an IP address or as an interface. If an interface is specified, it must have an associated IP address.

How to Configure MPLS Traffic Engineering: Tunnel Source

Configuring MPLS Traffic Engineering: Tunnel Source

Configuring MPLS Traffic Engineering: Tunnel Source

You can configure the tunnel source as an IP address or as an interface. If you configure the tunnel source as an interface, then you should configure an IP address for the interface.

To specify a tunnel source for an MPLS TE tunnel, perform the following steps:

SUMMARY STEPS

1. enable

2. configure terminal

3. interface tunnel number

4. ip unnumbered interface-type interface-number

5. no ip directed-broadcast

6. tunnel source {ip-address | interface-type interface-number}

7. tunnel destination {host-name | ip-address | ipv6-address}

8. tunnel mode mpls traffic-eng

9. tunnel mpls traffic-eng priority setup-priority [hold-priority]

10. tunnel mpls traffic-eng bandwidth bandwidth

11. tunnel mpls traffic-eng affinity affinity-value mask mask-value

12. tunnel mpls traffic-eng path-option number explicit name explicit-path-name

13. tunnel mpls traffic-eng autoroute announce

14. end

15. show ip rsvp sender

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 1

Configures a tunnel interface and enters interface configuration mode.

Step 4 

ip unnumbered interface-name interface-number

Example:

Router(config-if)# ip unnumbered loopback0

Configures an unnumbered IP interface, which enables IP processing without an explicit address.

An MPLS TE tunnel interface should be unnumbered because it represents a unidirectional link.

Step 5 

no ip directed-broadcast

Example:

Router(config-if)# no ip directed-broadcast

Disables the translation of a directed broadcast to physical broadcasts.

Step 6 

tunnel source {ip-address | interface-type interface-number}

Example:

Router(config-if)# tunnel source loopback1

Configures the tunnel source.

Step 7 

tunnel destination {host-name | ip-address | ipv6-address}

Example:

Router(config-if)# tunnel destination 192.168.2.1

Specifies the destination for a tunnel.

The destination must be the MPLS TE router ID of the destination device.

Step 8 

tunnel mode mpls traffic-eng

Example:

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

Sets the encapsulation mode of the tunnel to MPLS TE.

Step 9 

tunnel mpls traffic-eng priority setup-priority [hold-priority]

Example:

Router(config-if)# tunnel mpls traffic-eng priority 1 1

Sets the priority to be used when the system determines which existing tunnels are eligible to be preempted.

The setup-priority argument is the priority used when signaling an LSP for this tunnel to determine which existing tunnels can be preempted.
Valid values are from 0 to 7. A lower number indicates a higher priority. An LSP with a setup priority of 0 can preempt any LSP with a non-0 priority.

The hold-priority argument is the priority associated with an LSP for this tunnel to determine if it should be preempted by other LSPs that are being signaled.
Valid values are from 0 to 7, where a lower number indicates a higher priority.

Step 10 

tunnel mpls traffic-eng bandwidth bandwidth

Example:

Router(config-if)# tunnel mpls traffic-eng bandwidth 5000

Configures the bandwidth for the MPLS traffic engineering tunnel.

Step 11 

tunnel mpls traffic-eng affinity affinity value mask mask-value

Example:

Router(config-if)# tunnel mpls traffic-eng affinity 0x0 mask 0x0

Configures the properties an MPLS TE tunnel requires in its links.

Step 12 

tunnel mpls traffic-eng path-option number explicit name explicit-path-name

Example:

Router(config-if)# tunnel mpls traffic-eng path-option 1 explicit name BEST-WAY

Configures a path option for an MPLS TE tunnel.

The explicit keyword specifies that the path of the LSP is an IP explicit path.

Step 13 

tunnel mpls traffic-eng autoroute announce

Example:

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

Causes the IGP to use the tunnel in its enhanced shortest path first (SPF) calculation.

Step 14 

end

Example:

Router(config-if)# end

Exits interface configuration modes and enters privileged EXEC mode.

Step 15 

show ip rsvp sender

Example:

Router# show ip rsvp sender

Displays the IP address used as the source for tunnel control traffic.

Configuration Examples for MPLS Traffic Engineering: Tunnel Source

Example: MPLS Traffic Engineering—Tunnel Source, page 5

MPLS Traffic Engineering: Tunnel Source: Example

The output of the show running-config command displays the tunnel source configuration. If the tunnel source command is not configured, the IP address specified in the IGP command mpls traffic-eng router-id is used.

Router# show running-config
 
   
Building configuration...
 
   
Current configuration: 3969 bytes
!
!
interface Tunnel1
 ip unnumbered loopback0
 tunnel source loopback1
 tunnel mode mpls traffic-eng
 tunnel destination 192.168.2.1
 tunnel mpls traffic-eng priority 1 1
 tunnel mpls traffic-eng bandwidth 5000
 tunnel mpls traffic-eng affinity 0x0 mask 0x0
 tunnel mpls traffic-eng path-option 1 explicit name BEST-WAY
 tunnel mpls traffic-eng autoroute announce
 !
!
  ...
  router isis
   net 49.0000.0001.0000.0001.00
   is-type level-1
   metric-style wide
   mpls traffic-eng router-id Ethernet4/0/1
   mpls traffic-eng level-1
  !
 
   

The following sample output from the show ip rsvp sender command displays that the source IP address of the loopback interface used for tunnel control traffic:

Router# show ip rsvp sender
 
   
To              From            Pro DPort Sport    Prev Hop        I/F      BPS
192.168.2.1     192.168.42.2      0   1     13    192.168.42.10    Et0/0 SE LOAD 5M

Additional References

Related Documents

Related Topic
Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

MPLS commands

Cisco IOS Multiprotocol Label Switching Command Reference

MPLS TE automatic bandwidth adjustment for TE tunnels configuration tasks

MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels module

MPLS TE - LSP Attributes

MPLS Traffic Engineering—LSP Attributes module

MPLS TE: Path Protection

MPLS Traffic Engineering (TE) - Path Protection module


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Feature Information for MPLS Traffic Engineering: Tunnel Source

Table 1 lists the release history for this feature.

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.


Table 1 Feature Information for MPLS Traffic Engineering: Tunnel Source  

Feature Name
Releases
Feature Information

MPLS Traffic Engineering: Tunnel Source

12.2(33)SRD
12.2(33)SXI2
12.2(52)SE
15.0(1)M

The MPLS Traffic Engineering: Tunnel source feature allows you to specify the IP address assigned to an interface as the source IP address for control packets. The default behavior is to use the router ID configured in the IGP using the mpls traffic-eng router-id command.

The following command was introduced or modified: tunnel source.