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This document explains how to configure the MPLS LDP--VRF-Aware Static Labels feature and Multiprotocol Label Switching (MPLS) static labels. Virtual Private Network routing and forwarding (VRF)-aware static labels can be used at the edge of an MPLS Virtual Private Network (VPN), whereas MPLS static labels can be used only in the MPLS VPN provider core.
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 www.cisco.com/go/cfn. An account on Cisco.com is not required.
To configure and use VRF-aware static labels, you should understand the following concepts:
Label switch routers (LSRs) dynamically learn the labels they should use to label-switch packets by means of the following label distribution protocols:
The LSR installs the dynamically learned label into its Label Forwarding Information Base (LFIB).
You can configure static labels for the following purposes:
Before you can manually assign labels, you must reserve a range of labels to be used for the manual assignment. Reserving the labels ensures that the labels are not dynamically assigned. If you are running Cisco IOS Release 12.0S or an older release, you may need to reload the router for the range of labels you reserve to take effect.
The following procedure explains how to reserve the labels that are to be statically assigned so that the labels are not dynamically assigned.
MPLS static labels allow you to configure entries in the MPLS forwarding table and assign label values to FECs learned by LDP. You can manually configure an LSP without running a label distribution protocol between the endpoints. In MPLS VPN networks, static labels can be used only in the MPLS VPN provider core.
Command or Action | Purpose | |
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Example: Router> enable |
Enables privileged EXEC mode.
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Example: Router# configure terminal |
Enters global configuration mode and returns to privileged EXEC mode. |
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Example: Router(config)# mpls static binding ipv4 10.2.2.0 255.255.255.255 input 17 |
Specifies static binding of labels to IPv4 prefixes. Specified bindings are installed automatically in the MPLS forwarding table as routing demands. |
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Example: Router(config)# end |
Exits global configuration mode and enters privileged EXEC mode. |
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Example: Router# show mpls static binding ipv4 |
Displays the configured static labels. |
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Example: Router# show mpls forwarding-table |
Displays the static labels used for MPLS forwarding. |
You can configure MPLS static cross connects to support MPLS LSP midpoints when neighbor routers do not implement either the LDP or RSVP label distribution, but do implement an MPLS forwarding path.
Note |
|
Command or Action | Purpose | |||
---|---|---|---|---|
|
Example: Router> enable |
Enables privileged EXEC mode.
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Example: Router# configure terminal |
Enters global configuration mode. |
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Example: Router(config)# mpls static crossconnect 45 pos5/0 45 explicit-null |
Specifies static cross connects.
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Example: Router(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
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Example: Router# show mpls static crossconnect |
Displays the configured static cross connects. |
You can statically bind a VRF-aware label on a PE router to a customer network prefix (VPN IPv4 prefix). VRF-aware static labels can be used with nonglobal VRF tables, so the labels can be used at the VPN edge.
Note |
The MPLS LDP-VRF-Aware Static Labels feature is supported only with MPLS VPN Carrier Supporting Carrier networks that use MPLS LDP. |
Command or Action | Purpose | |||
---|---|---|---|---|
|
Example: Router> enable |
Enables privileged EXEC mode. |
||
|
Example: Router# configure terminal |
Enters global configuration mode. |
||
|
Example: Router(config)# mpls static binding ipv4 vrf vpn100 10.2.0.0 255.255.0.0 input 17 |
Binds a prefix to a local label. Specified bindings are installed automatically in the MPLS forwarding table as routing demands.
|
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Example: Router(config)# end |
Exits global configuration mode and enters privileged EXEC mode. |
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|
Example: Router(config)# show mpls static binding ipv4 vrf vpn100 |
Displays the configured MPLS static bindings. |
To display information related to static binding events, use the debug mpls static binding vrf command.
In the following example, the mpls label range command reserves a generic range of labels from 200 to 100000 and configures a static label range of 16 to 199:
Router(config)# mpls label range 200 100000 static 16 199
% Label range changes take effect at the next reload.
In this example, the output from the show mpls label range command indicates that the new label ranges do not take effect until a reload occurs:
Router# show mpls label range
Downstream label pool: Min/Max label: 16/100000
[Configured range for next reload: Min/Max label: 200/100000]
Range for static labels: Min/Max/Number: 16/199
In the following output, the show mpls label range command, executed after a reload, indicates that the new label ranges are in effect:
Router# show mpls label range
Downstream label pool: Min/Max label: 200/100000
Range for static labels: Min/Max/Number: 16/199
The following example configures input and output labels for several prefixes:
Router(config)# mpls static binding ipv4 10.0.0.0 255.0.0.0 55 Router(config)# mpls static binding ipv4 10.0.0.0 255.0.0.0 output 10.0.0.66 167 Router(config)# mpls static binding ipv4 10.66.0.0 255.255.0.0 input 17 Router(config)# mpls static binding ipv4 10.66.0.0 255.255.0.0 output 10.13.0.8 explicit-null
The show mpls static binding ipv4command displays the configured static labels:
Router# show mpls static binding ipv4
10.0.0.0/8: Incoming label: 55
Outgoing labels:
10.0.0.66 167
10.66.0.0/24: Incoming label: 17
Outgoing labels:
10.13.0.8 explicit-null
In the following example, the mpls static crossconnect command configures a cross connect from incoming label 45 to outgoing label 46 on the POS interface 5/0:
Router(config)# mpls static crossconnect 45 pos5/0 46
The show mpls static crossconnect command displays information about cross connects that have been configured:
Router# show mpls static crossconnect Local Outgoing Outgoing Next Hop label label interface 45 46 pos5/0 point2point (in LFIB)
In the following example, the mpls static binding ipv4 vrf commands configure static label bindings. They also configure input (local) labels for various prefixes.
Router(config)# mpls static binding ipv4 vrf vpn100 10.0.0.0 10.0.0.0 55 Router(config)# mpls static binding ipv4 vrf vpn100 10.66.0.0 255.255.0.0 input 17
In the following output, the show mpls static binding ipv4 vrfcommand displays the configured VRF-aware static bindings:
Router# show mpls static binding ipv4 vrf vpn100 10.0.0.0/8: (vrf: vpn100) Incoming label: 55 Outgoing labels: None 10.66.0.0/16: (vrf: vpn100) Incoming label: 17 Outgoing labels: None
The following sections provide references related to the MPLS LDP--VRF-Aware Static Labels feature.
Related Topic |
Document Title |
---|---|
MPLS VPN CSC with LDP and IGP |
MPLS VPN Carrier Supporting Carrier Using LDP and IGP |
Standard |
Title |
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
-- |
MIB |
MIBs Link |
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No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFC |
Title |
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No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
-- |
Description |
Link |
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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 commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS Multiprotocol Label Switching Command Reference at http://www.cisco.com/en/US/docs/ios/mpls/command/reference/mp_book.html . For information about all Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or the Cisco IOS Master Command List, All Releases , at http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html .
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 www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1 | Feature Information for MPLS LDP--VRF-Aware Static Labels |
Feature Name |
Releases |
Feature Information |
---|---|---|
MPLS LDP-VRF-Aware Static Labels |
12.0(23)S 12.0(26)S 12.3(14)T 12.2(33)SRA 12.2(33)SXH 12.2(33)SB |
The MPLS LDP-VRF-Aware Static Labels feature explains how to configure the MPLS LDP--VRF-Aware Static Labels feature and MPLS static labels. VVRF-aware static labels can be used at the edge of an MPLS VPN, whereas MPLS static labels can be used only in the MPLS VPN provider core. In 12.0(23)S, MPLS static labels were introduced, but they supported only global routing tables. In 12.0(26)S, the MPLS LDP--VRF-Aware Static Labels feature was introduced, allowing MPLS static labels to be used for VRF traffic at the VPN edge. In 12.3(14)T, this feature was integrated. In 12.2(33)SRA, this feature was integrated. In 12.2(33)SXH, this feature was integrated. In 12.2(33)SB, support was added for the Cisco 10000 series router. |
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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.