OSPF Support for Forwarding Adjacencies over MPLS Traffic Engineered Tunnels
The OSPF Support for Forwarding Adjacencies over MPLS Traffic Engineered Tunnels feature adds Open Shortest Path First (OSPF) support to the Multiprotocol Label Switching (MPLS) Traffic Engineering (TE) Forwarding Adjacency feature, which allows a network administrator to handle a traffic engineering, label-switched path (LSP) tunnel as a link in an Interior Gateway Protocol (IGP) network based on the shortest path first (SPF) algorithm. An OSPF forwarding adjacency can be created between routers in the same area.
History for the OSPF Support for Forwarding Adjacencies over MPLS Traffic Engineered Tunnels Feature
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12.0(24)S |
This feature was introduced. |
12.2(25)S |
This feature was integrated into Cisco IOS Release 12.2(25)S. |
12.2(18)SXE |
This feature was integrated into Cisco IOS Release 12.2(18)SXE. |
12.2(27)SBC |
This feature was integrated into Cisco IOS Release 12.2(27)SBC. |
Cisco IOS XE Release 2.1 |
This feature was implemented on Cisco ASR 1000 series routers. |
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents
•Prerequisites for OSPF Forwarding Adjacency
•Information About OSPF Forwarding Adjacency
•How to Configure OSPF Forwarding Adjacency
•Configuration Examples for OSPF Forwarding Adjacency
•Additional References
•Command Reference
Prerequisites for OSPF Forwarding Adjacency
•OSPF must be configured in your network.
•Cisco Express Forwarding (CEF) must be enabled.
•You should understand MPLS TE tunnels for forwarding adjacency as described in the "MPLS Traffic Engineering Forwarding Adjacency" module.
Information About OSPF Forwarding Adjacency
OSPF includes MPLS TE tunnels in the OSPF link-state database in the same way that other links appear for purposes of routing and forwarding traffic. When an MPLS TE tunnel is configured between networking devices, that link is considered a forwarding adjacency. The user can assign a cost to the tunnel to indicate the link's preference. Other networking devices will see the tunnel as a link in addition to the physical link.
How to Configure OSPF Forwarding Adjacency
Configuring OSPF Forwarding Adjacency
Note Configure a forwarding adjacency on two LSP tunnels bidirectionally, from A to B and B to A. Otherwise, the forwarding adjacency is advertised, but not used in the IGP network.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip cef distributed
4. mpls traffic-eng tunnels
5. interface loopback number
6. ip address ip-address mask
7. no shutdown
8. exit
9. interface tunnel number
10. tunnel mode mpls traffic-eng
11. tunnel mpls traffic-eng forwarding-adjacency {holdtime value}
12. ip ospf cost cost
13. exit
14. router ospf process-id
15. mpls traffic-eng router-id interface
16. mpls traffic-eng area number
17. end
DETAILED STEPS
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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 Cisco Express Forwarding (CEF). |
Step 4 |
mpls traffic-eng tunnels
Router(config)# mpls traffic-eng tunnels |
Enables MPLS traffic engineering tunnel signaling on a device. |
Step 5 |
interface loopback number
Router(config)# interface loopback0 |
Configures a loopback interface and enters interface configuration mode. •Set up a loopback interface with a 32-bit mask, enable CEF, enable MPLS traffic engineering, and set up a routing protocol (OSPF) for the MPLS network. |
Step 6 |
ip address ip-address mask
Router(config-if)# ip address 10.1.1.1 255.255.255.255 |
Configures the IP address and subnet mask of the loopback interface. |
Step 7 |
no shutdown
Router(config-if)# no shutdown |
Enables the interface. |
Step 8 |
exit
Router(config-if)# exit |
Exits interface configuration mode. |
Step 9 |
interface tunnel number
Router(config)# interface tunnel 1 |
Designates a tunnel interface for the forwarding adjacency and enters interface configuration mode. |
Step 10 |
tunnel mode mpls traffic-eng
Router(config-if)# tunnel mode mpls traffic-eng |
Sets the mode of a tunnel to MPLS for traffic engineering. |
Step 11 |
tunnel mpls traffic-eng forwarding-adjacency {holdtime value}
Router(config-if)# tunnel mpls traffic-eng forwarding-adjacency holdtime 10000 |
Advertises a TE tunnel as a link in an IGP network. •The holdtime value keyword argument combination is the time in milliseconds (ms) that a TE tunnel waits after going down before informing the network. The range is 0 to 4,294,967,295 ms. The default value is 0. |
Step 12 |
ip ospf cost cost
Router(config-if)# ip ospf cost 4 |
(Optional) Configures the cost metric for a tunnel interface to be used as a forwarding adjacency. |
Step 13 |
exit
Router(config-if)# exit |
Exits interface configuration mode. |
Step 14 |
router ospf process-id
Router(config)# router ospf 1 |
Configures an OSPF routing process and enters router configuration mode. |
Step 15 |
mpls traffic-eng router-id interface
Router(config-router)# mpls traffic-eng router-id ethernet 1/0 |
Specifies that the traffic engineering router identifier for the node is the IP address associated with a given interface. |
Step 16 |
mpls traffic-eng area number
Router(config-router)# mpls traffic-eng area 1 |
Configures a router running OSPF MPLS so that it floods traffic engineering for the indicated OSPF area. |
Step 17 |
end
Router(config-router)# end |
Exits router configuration mode. |
Configuration Examples for OSPF Forwarding Adjacency
Example: OSPF Forwarding Adjacency
In the following example, the tunnel destination is the loopback interface on the other router. The router is configured with OSPF TE extensions and it floods traffic engineering link-state advertisements (LSAs) in OSPF area 0. The traffic engineering router identifier for the node is the IP address associated with Loopback 0. The last five lines of the example set up the routing protocol for the MPLS network, which is OSPF in this case.
Note Do not use the mpls traffic-eng autoroute announce command if you configure a forwarding adjacency in the tunnel.
ip address 127.0.0.1 255.255.255.255
tunnel destination 10.1.1.1
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng forwarding-adjacency holdtime 10000
tunnel mpls traffic-eng priority 2 2
tunnel mpls traffic-eng bandwidth 10
tunnel mpls traffic-eng path-option 2 dynamic
network 10.1.1.1 0.0.0.0 area 0
mpls traffic-eng router-id loopback0
When you look at the self-generated router LSA, you will see it as one of the links in router LSA (shown in bold in the following output).
Router# show ip ospf database route self-originate
OSPF Router with ID (10.5.5.5) (Process ID 5)
Router Link States (Area 0)
Options:(No TOS-capability, DC)
Advertising Router:10.5.5.5
Link connected to another Router (point-to-point)
(Link ID) Neighboring Router ID:10.3.3.3
(Link Data) Router Interface address:0.0.0.23
Link connected to:a Transit Network
(Link ID) Designated Router address:172.16.0.1
(Link Data) Router Interface address:172.16.0.2
Link connected to:a Transit Network
(Link ID) Designated Router address:172.16.0.3
(Link Data) Router Interface address:172.16.0.4
Link connected to:a Stub Network
(Link ID) Network/subnet number:10.5.5.5
(Link Data) Network Mask:255.255.255.255
Additional References
The following sections provide references related to OSPF Forwarding Adjacency.
Related Documents
Standards
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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. |
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MIBs
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None |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs |
RFCs
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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. |
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Technical Assistance
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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 |
Command Reference
This feature uses no new or modified commands.
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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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