MPLS Layer 3 VPNs Inter-AS and CSC Configuration Guide, Cisco IOS XE Release 3S
MPLS VPN Carrier Supporting Carrier Using LDP and an IGP
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MPLS VPN Carrier Supporting Carrier Using LDP and an IGP

Contents

MPLS VPN Carrier Supporting Carrier Using LDP and an IGP

Multiprotocol Label Switching (MPLS) Virtual Private Network (VPN) Carrier Supporting Carrier (CSC) enables one MPLS VPN-based service provider to allow other service providers to use a segment of its backbone network. This module explains how to configure the MPLS VPN CSC network using MPLS Label Distribution Protocol (LDP) to distribute MPLS labels and an Interior Gateway Protocol (IGP) to distribute routes.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 module.

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.

Prerequisites for MPLS VPN CSC with LDP and IGP

  • The provider edge (PE) routers of the backbone carrier require 128 MB of memory.
  • The backbone carrier must enable the PE router to check that the packets it receives from the customer edge (CE) router contain only the labels that the PE router advertised to the CE router. This prevents data spoofing, which occurs when a packet from an unrecognized IP address is sent to a router.

Restrictions for MPLS VPN CSC with LDP and IGP

The following features are not supported with this feature:

  • ATM MPLS
  • Carrier supporting carrier traffic engineering
  • Carrier supporting carrier quality of service (QoS)
  • RSVP aggregation
  • VPN Multicast between the customer carrier and the backbone carrier network

The following router platforms are supported on the edge of the MPLS VPN:

  • Cisco 7200 series
  • Cisco 7500 series
  • Cisco 12000 series

See the table below for Cisco 12000 series line card support added for Cisco IOS releases.

Table 1 Cisco12000 Series Line Card Support Added for Cisco IOS Releases

Type

Line Cards

Cisco IOS Release Added

Packet over SONET (POS)

4-Port OC-3 POS

1-Port OC-12 POS

8-Port OC-3 POS

16-Port OC-3 POS

4-Port OC-12 POS

1-Port OC-48 POS

4-Port OC-3 POS ISE

8-Port OC-3 POS ISE

16 x OC-3 POS ISE

4 Port OC-12 POS ISE

1-Port OC-48 POS ISE

12.0(16)ST

12.0(21)ST

12.0(22)S

Electrical Interface

6- Port DS3

12- Port DS3

6-Port E3

12.0(16)ST

12.0(21)ST

ATM

4-Port OC-3 ATM

1-Port OC12 ATM

4-Port OC-12 ATM

12.0(22)S

Channelized Interface

2-Port CHOC-3

6-Port Ch T3 (DS1)

1-Port CHOC-12 (DS3)

1-Port CHOC-12 (OC-3)

4-Port CHOC-12 ISE

1-Port CHOC-48 ISE

12.0(22)S

Information About MPLS VPN CSC with LDP and IGP

MPLS VPN CSC Introduction

Carrier supporting carrier is where one service provider allows another service provider to use a segment of its backbone network. The service provider that provides the segment of the backbone network to the other provider is called the backbone carrier. The service provider that uses the segment of the backbone network is called the customer carrier.

A backbone carrier offers Border Gateway Protocol and Multiprotocol Label Switching (BGP/MPLS) VPN services. The customer carrier can be either:

  • An Internet service provider (ISP)
  • A BGP/MPLS VPN service provider

Benefits of Implementing MPLS VPN CSC

The MPLS VPN CSC network provides the following benefits to service providers who are backbone carriers and to customer carriers.

Benefits to the Backbone Carrier

  • The backbone carrier can accommodate many customer carriers and give them access to its backbone. The backbone carrier does not need to create and maintain separate backbones for its customer carriers. Using one backbone network to support multiple customer carriers simplifies the backbone carrier’s VPN operations. The backbone carrier uses a consistent method for managing and maintaining the backbone network. This is also cheaper and more efficient than maintaining separate backbones.
  • The MPLS VPN carrier supporting carrier feature is scalable. Carrier supporting carrier can change the VPN to meet changing bandwidth and connectivity needs. The feature can accommodate unplanned growth and changes. The carrier supporting carrier feature enables tens of thousands of VPNs to be set up over the same network, and it allows a service provider to offer both VPN and Internet services.
  • The MPLS VPN carrier supporting carrier feature is a flexible solution. The backbone carrier can accommodate many types of customer carriers. The backbone carrier can accept customer carriers who are ISPs or VPN service providers or both. The backbone carrier can accommodate customer carriers that require security and various bandwidths.

Benefits to the Customer Carriers

  • The MPLS VPN carrier supporting carrier feature removes from the customer carrier the burden of configuring, operating, and maintaining its own backbone. The customer carrier uses the backbone network of a backbone carrier, but the backbone carrier is responsible for network maintenance and operation.
  • Customer carriers who use the VPN services provided by the backbone carrier receive the same level of security that Frame Relay or ATM-based VPNs provide. Customer carriers can also use IPSec in their VPNs for a higher level of security; it is completely transparent to the backbone carrier.
  • Customer carriers can use any link layer technology (SONET, DSL, Frame Relay, and so on) to connect the CE routers to the PE routers and the PE routers to the P routers. The MPLS VPN carrier supporting carrier feature is link layer independent. The CE routers and PE routers use IP to communicate, and the backbone carrier uses MPLS.
  • The customer carrier can use any addressing scheme and still be supported by a backbone carrier. The customer address space and routing information are independent of the address space and routing information of other customer carriers or the backbone provider.

Configuration Options for MPLS VPN CSC with LDP and IGP

The backbone carrier offers BGP and MPLS VPN services. The customer carrier can be one of the two types of service providers described in the following sections, which explain how the backbone and customer carriers distribute IPv4 routes and MPLS labels.

Customer Carrier Is an ISP

This section explains how a BGP/MPLS VPN service provider (backbone carrier) can provide a segment of its backbone network to a customer who is an ISP.

Consider the following example:

An ISP has two sites: one in California, the other in Maine. Each site is a point of presence (POP). The ISP wants to connect these sites using a VPN service provided by a backbone carrier. The figure below illustrates this situation.

Figure 1. Sample BGP/MPLS Backbone Carrier Supporting an ISP


Note


The CE routers in the figures are CE routers to the backbone carrier. However, they are PE routers to the customer carrier.


In this example, only the backbone carrier uses MPLS. The customer carrier (ISP) uses only IP. As a result, the backbone carrier must carry all the Internet routes of the customer carrier, which could be as many as 100,000 routes. This poses a scalability problem for the backbone carrier. To solve the scalability problem, the backbone carrier is configured as follows:

  • The backbone carrier allows only internal routes of the customer carrier (IGP routes) to be exchanged between the CE routers of the customer carrier and the PE routers of the backbone carrier.
  • MPLS is enabled on the interface between the CE router of the customer carrier and the PE router of the backbone carrier.

Internal and external routes are differentiated this way:

  • Internal routes go to any of the routers within the ISP.
  • External routes go to the Internet.

The number of internal routes is much lower than the number of external routes. Restricting the routes between the CE routers of the customer carrier and the PE routers of the backbone carrier significantly reduces the number of routes that the PE router needs to maintain.

Because the PE routers do not have to carry external routes in the VRF routing table, they can use the incoming label in the packet to forward the customer carrier Internet traffic. Adding MPLS to the routers provides a consistent method of transporting packets from the customer carrier to the backbone carrier. MPLS allows the exchange of an MPLS label between the PE and the CE routers for every internal customer carrier route. The routers in the customer carrier have all the external routes either through internal Border Gateway Protocol (iBGP) or route redistribution to provide Internet connectivity. The figure below shows how information is exchanged when the network is configured in this manner.

Figure 2. Backbone Carrier Exchanging Routing Information with a Customer Carrier Who Is an ISP

In the figure below, routes are created between the backbone carrier and the customer carrier sites. ASBR2 receives an Internet route that originated outside the network. All routers in the ISP sites have all the external routes through IBGP connections among them.

Figure 3. Establishing a Route Between a Backbone Carrier and a Customer Carrier Who Is an ISP

The table below describes the process of establishing the route, which can be divided into two distinct steps:

  • The backbone carrier propagates the IGP information of the customer carrier, which enables the customer carrier routers to reach all the customer carrier routers in the remote sites.
  • Once the routers of the customer carriers in different sites are reachable, external routes can be propagated in the customer carrier sites, using IBGP without using the backbone carrier routers.
Table 2 Establishing a Route Between the Backbone Carrier and the Customer Carrier ISP

Step

Description

1

CSC-CE2 sends the internal routes within site 2 to CSC-PE2. The routes include the route to ASBR2.

2

CSC-PE2 sends the routing information for site 2 to CSC-PE1, using MPLS VPN processes. CSC-PE1 gets one label (called L3), which is associated with the route to the VPN-IP address for ASBR2. CSC-PE1 gets another label (called L2), which is associated with the route to CSC-PE2.

3

CSC-PE1 sends the routing information associated with internal routes from site 2 to CSC-CE1. CSC-PE1 also sends the label binding information. As a result, CSC-CE1 gets the route to ASBR2 with CSC-PE1 as the next hop. The label associated with that route is called L1.

4

CSC-CE1 distributes the routing information through site 1. Every router in site 1 gets a route for every internal destination in site 2. Therefore, every router in site 1 can reach routers in site 2 and learn external routes through IBGP.

5

ASBR2 receives an Internet route.

6

The IBGP sessions exchange the external routing information of the ISP, including a route to the Internet. Every router in site 1 knows a route to the Internet, with ASBR2 as the next hop of that route.

Customer Carrier Is a BGP MPLS VPN Service Provider

When a backbone carrier and the customer carrier both provide BGP/MPLS VPN services, the method of transporting data is different from when a customer carrier provides only ISP services. The following list highlights those differences:

  • When a customer carrier provides BGP/MPLS VPN services, its external routes are VPN-IPv4 routes. When a customer carrier is an ISP, its external routes are IP routes.
  • When a customer carrier provides BGP/MPLS VPN services, every site within the customer carrier must use MPLS. When a customer carrier is an ISP, the sites do not need to use MPLS.

The figure below shows how information is exchanged when MPLS VPN services reside on all customer carrier sites and on the backbone carrier.

Figure 4. Backbone Carrier Exchanging Information with a Customer Carrier Who Is an MPLS VPN Service Provider

In the example shown in the figure below, routes are created between the backbone carrier and the customer carrier sites.

Figure 5. Establishing a Route Between a Backbone Carrier and a Customer Carrier Who Is an MPLS VPN Service Provider

The table below describes the process of establishing the route.

Table 3 Establishing a Route Between the Backbone Carrier and Customer Carrier Site

Step

Description

1

CE2 sends all the internal routes within site 2 to CSC-PE2.

2

CSC-PE2 sends the routing information for site 2 to CSC-PE1, using MPLS VPN processes. CSC-PE1 gets one label (called L3), which is associated with the route to the VPN-IP address for PE2. CSC-PE1 gets another label (called L2), which is associated with the route to CSC-PE2.

3

CSC-PE1 sends the routing information associated with internal routes from site 2 to CSC-CE1. CSC-PE1 also sends the label binding information. As a result, CSC-CE1 gets the route to PE2 with CSC-PE1 as the next hop. The label associated with that route is called L1.

4

CE1 distributes the routing and labeling information through site 1. Every router in site 1 gets a route for every internal destination in site 2. Therefore, PE1 can establish an MP-IBGP session with PE2.

5

CE2 advertises the internal routes of MPLS VPN site 2 to PE2.

6

PE2 allocates labels for all the VPN routes (regular MPLS VPN functionality) and advertises the labels to PE1, using MP-IBGP.

7

PE1 can forward traffic from VPN site 1 that is destined for VPN site 2.

How to Configure MPLS VPN CSC with LDP and IGP

Configuring the Backbone Carrier Core

Configuring the backbone carrier core requires configuring connectivity and routing functions for the CSC core and the CSC-PE routers.

Configuring and verifying the CSC core (backbone carrier) involves the following tasks:

Prerequisites

Before you configure a backbone carrier core, configure the following on the CSC core routers:

  • An IGP routing protocol--BGP, OSPF, IS-IS, EIGRP, static, and so on. For information, see Configuring a Basic BGP Network, Configuring OSPF, Configuring a Basic IS-IS Network, and Configuring EIGRP.
  • Label Distribution Protocol (LDP). For information, see MPLS Label Distribution Protocol.

Verifying IP Connectivity and LDP Configuration in the CSC Core

Perform this task to verify IP connectivity and LDP configuration in the CSC core. For a configuration example for this task, see the Verifying IP Connectivity and LDP Configuration in the CSC Core.

SUMMARY STEPS

    1.    enable

    2.    ping [protocol] {host-name | system-address}

    3.    trace [protocol] [destination]

    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 ldp discovery [vrf vrf-name | all]

    6.    show mpls ldp neighbor [[vrf vrf-name] [address | interface] [detail] | all]

    7.    show ip cef [vrf vrf-name] [network [mask]] [longer-prefixes] [detail]

    8.    show mpls interfaces [[vrf vrf-name] [interface] [detail] |all]

    9.    show ip route

    10.    disable


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Router> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.
     
    Step 2 ping [protocol] {host-name | system-address}


    Example:
    Router# ping ip 10.0.0.1
     

    (Optional) Diagnoses basic network connectivity on AppleTalk, Connectionless Network Service (CLNS), IP, Novell, Apollo, VINES, DECnet, or Xerox Network System (XNS) networks.

    • Use the ping ip command to verify the connectivity from one CSC core router to another.
     
    Step 3 trace [protocol] [destination]


    Example:
    Router# trace ip 10.0.0.1
     

    (Optional) Discovers the routes that packets will actually take when traveling to their destination.

    • Use the trace command to verify the path that a packet goes through before reaching the final destination. The trace command can help isolate a trouble spot if two routers cannot communicate.
     
    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]


    Example:
    Router# show mpls forwarding-table
     

    (Optional) Displays the contents of the MPLS label forwarding information base (LFIB).

    • Use the show mpls forwarding-table command to verify that MPLS packets are being forwarded.
     
    Step 5 show mpls ldp discovery [vrf vrf-name | all]


    Example:
    Router# show mpls ldp discovery
     

    (Optional) Displays the status of the LDP discovery process.

    • Use the show mpls ldp discovery command to verify that LDP is operational in the CSC core.
     
    Step 6 show mpls ldp neighbor [[vrf vrf-name] [address | interface] [detail] | all]


    Example:
    Router# show mpls ldp neighbor
     

    (Optional) Displays the status of LDP sessions.

    • Use theshow mpls ldp neighbor command to verify LDP configuration in the CSC core.
     
    Step 7 show ip cef [vrf vrf-name] [network [mask]] [longer-prefixes] [detail]


    Example:
    Router# show ip cef 
     

    (Optional) Displays entries in the forwarding Information Base (FIB).

    • Use the show ip cef command to check the forwarding table (prefixes, next hops, and interfaces).
     
    Step 8 show mpls interfaces [[vrf vrf-name] [interface] [detail] |all]


    Example:
    Router# show mpls interfaces 
     

    (Optional) Displays information about one or more or all interfaces that are configured for label switching.

    • Use theshow mpls interfaces command to verify that the interfaces are configured to use LDP.
     
    Step 9 show ip route


    Example:
    Router# show ip route
     

    (Optional) Displays IP routing table entries.

    • Use the show ip route command to display the entire routing table, including host IP address, next hop, and interface.
     
    Step 10 disable


    Example:
    Router# disable
     

    (Optional) Returns to privileged EXEC mode.

     
    Troubleshooting Tips

    You can use the ping and trace commands to verify complete MPLS connectivity in the core. You also get useful troubleshooting information from the additional show commands.

    Configuring VRFs for CSC-PE Routers

    Perform this task to configure VPN routing and forwarding (VRF) instances for the backbone carrier edge (CSC-PE) routers.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    ip vrf vrf-name

      4.    rd route-distinguisher

      5.    route-target {import | export | both} route-target-ext-community

      6.    import map route-map

      7.    exit

      8.    interface type number

      9.    ip vrf forwarding vrf-name

      10.    end


    DETAILED STEPS
       Command or ActionPurpose
      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 ip vrf vrf-name


      Example:
      Router(config)# ip vrf vpn1
       

      Defines the VPN routing instance by assigning a VRF name and enters VRF configuration mode.

      • The vrf-name argument is the name assigned to a VRF.
       
      Step 4 rd route-distinguisher


      Example:
      Router(config-vrf)# rd 100:1
       

      Creates routing and forwarding tables.

      • The route-distinguisher argument adds an 8-byte value to an IPv4 prefix to create a VPN-IPv4 prefix. You can enter an RD in either of these formats:
        • 16-bit AS number: your 32-bit number, for example, 101:3
        • 32-bit IP address: your 16-bit number, for example, 192.168.122.15:1
       
      Step 5 route-target {import | export | both} route-target-ext-community


      Example:
      Router(config-vrf)# route-target import 100:1
       

      Creates a route-target extended community for a VRF.

      • The import keyword imports routing information from the target VPN extended community.
      • The export keyword exports routing information to the target VPN extended community.
      • The both keyword imports routing information from and exports routing information to the target VPN extended community.
      • The route-target-ext-community argument adds the route-target extended community attributes to the VRF’s list of import, export, or both (import and export) route-target extended communities.
       
      Step 6 import map route-map


      Example:
      Router(config-vrf)# import map vpn1-route-map
       

      (Optional) Configures an import route map for a VRF.

      • The route-map argument specifies the route map to be used as an import route map for the VRF.
       
      Step 7 exit


      Example:
      Router(config-vrf)# exit
       

      (Optional) Exits to global configuration mode.

       
      Step 8 interface type number


      Example:
      Router(config)# interface Ethernet5/0
       

      Specifies the interface to configure and enters interface configuration mode.

      • The type argument specifies the type of interface to be configured.
      • The number argument specifies the port, connector, or interface card number.
       
      Step 9 ip vrf forwarding vrf-name


      Example:
      Router(config-if)# ip vrf forwarding vpn1
       

      Associates a VRF with the specified interface or subinterface.

      • The vrf-name argument is the name assigned to a VRF.
       
      Step 10 end


      Example:
      Router(config-if)# end 
       

      (Optional) Exits to privileged EXEC mode.

       
      Troubleshooting Tips

      Enter a show ip vrf detail command and make sure the MPLS VPN is up and associated with the right interfaces.

      Configuring Multiprotocol BGP for VPN Connectivity in the Backbone Carrier

      Perform this task to configure Multiprotocol BGP (MP-BGP) connectivity in the backbone carrier.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    router bgp as-number

        4.    no bgp default ipv4-unicast

        5.    neighbor {ip-address | peer-group-name} remote-as as-number

        6.    neighbor {ip-address | peer-group-name} update-source interface-type

        7.    address-family vpnv4 [unicast]

        8.    neighbor {ip-address | peer-group-name} send-community extended

        9.    neighbor {ip-address | peer-group-name} activate

        10.    end


      DETAILED STEPS
         Command or ActionPurpose
        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 router bgp as-number


        Example:
        Router(config)# router bgp 100
         

        Configures a BGP routing process and enters router configuration mode.

        • The as-number argument indicates the number of an autonomous system that identifies the router to other BGP routers and tags the routing information passed along. Valid numbers are from 0 to 65535. Private autonomous system numbers that can be used in internal networks range from 64512 to 65535.
         
        Step 4 no bgp default ipv4-unicast


        Example:
        Router(config-router)# no bgp default ipv4-unicast
         

        (Optional) Disables the IPv4 unicast address family on all neighbors.

        • Use the no bgp default-unicast command if you are using this neighbor for MPLS routes only.
         
        Step 5 neighbor {ip-address | peer-group-name} remote-as as-number


        Example:
        Router(config-router)# neighbor 10.5.5.5 remote-as 100
         

        Adds an entry to the BGP or multiprotocol BGP neighbor table.

        • The ip-address argument specifies the IP address of the neighbor.
        • The peer-group-name argument specifies the name of a BGP peer group.
        • The as-number argument specifies the autonomous system to which the neighbor belongs.
         
        Step 6 neighbor {ip-address | peer-group-name} update-source interface-type


        Example:
        Router(config-router)# neighbor 10.2.0.0 update-source loopback0
         

        Allows BGP sessions to use a specific operational interface for TCP connections.

        • The ip-address argument specifies the IP address of the BGP-speaking neighbor.
        • The peer-group-name argument specifies the name of a BGP peer group.
        • The interface-type argument specifies the interface to be used as the source.
         
        Step 7 address-family vpnv4 [unicast]


        Example:
        Router(config-router)# address-family vpnv4
         

        Enters address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

        • The optional unicast keyword specifies VPNv4 unicast address prefixes.
         
        Step 8 neighbor {ip-address | peer-group-name} send-community extended


        Example:
        Router(config-router-af)# neighbor 10.0.0.1 send-community extended
         

        Specifies that a communities attribute should be sent to a BGP neighbor.

        • The ip-address argument specifies the IP address of the BGP-speaking neighbor.
        • The peer-group-name argument specifies the name of a BGP peer group.
         
        Step 9 neighbor {ip-address | peer-group-name} activate


        Example:
        Router(config-router-af)# neighbor 10.4.0.0 activate
         

        Enables the exchange of information with a neighboring BGP router.

        • The ip-address argument specifies the IP address of the neighbor.
        • The peer-group-name argument specifies the name of a BGP peer group.
         
        Step 10 end


        Example:
        Router(config-router-af)# end
         

        (Optional) Exits to privileged EXEC mode.

         
        Troubleshooting Tips

        You can enter a show ip bgp neighbor command to verify that the neighbors are up and running. If this command generates an error message, enter a debug ip bgp x.x.x.x events command, where x.x.x.x is the IP address of the neighbor.

        Configuring the CSC-PE and CSC-CE Routers

        To enable the CSC-PE and CSC-CE routers to distribute routes and MPLS labels, perform the following tasks:

        Prerequisites

        Before you configure the CSC-PE and CSC-CE routers, you must configure an IGP on the CSC-PE and CSC-CE routers. A routing protocol is required between the PE and CE routers that connect the backbone carrier to the customer carrier. The routing protocol enables the customer carrier to exchange IGP routing information with the backbone carrier. Use the same routing protocol that the customer carrier uses. You can choose RIP, OSPF, or static routing as the routing protocol. BGP is not supported. For the configuration steps, see Configuring MPLS Layer 3 VPNs .

        Configuring LDP on the CSC-PE and CSC-CE Routers

        MPLS LDP is required between the PE and CE routers that connect the backbone carrier to the customer carrier. You can configure LDP as the default label distribution protocol for the entire router or just for the PE-to-CE interface for VRF.

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    mpls label protocol ldp

          4.    interface type number

          5.    mpls label protocol ldp

          6.    exit


        DETAILED STEPS
           Command or ActionPurpose
          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 mpls label protocol ldp


          Example:
          Router(config)# mpls label protocol ldp
           
          
           

          Specifies MPLS LDP as the default label distribution protocol for the router.

           
          Step 4 interface type number


          Example:
          Router(config)# interface Ethernet5/0
           

          (Optional) Specifies the interface to configure and enters interface configuration mode.

          • The type argument specifies the type of interface to be configured.
          • The number argument specifies the port, connector, or interface card number.
           
          Step 5 mpls label protocol ldp


          Example:
          Router(config-if)# mpls label protocol ldp
           

          (Optional) Specifies MPLS LDP as the default label distribution protocol for the interface.

           
          Step 6 exit


          Example:
          Router(config-if)# exit
           

          (Optional) Exits to privileged EXEC mode.

           

          Enabling MPLS Encapsulation on the CSC-PE and CSC-CE Routers

          Every packet that crosses the backbone carrier must be encapsulated, so that the packet includes MPLS labels. You can enable MPLS encapsulation for the entire router or just on the interface of the PE or CE router. To enable the encapsulation of packets, perform the following task.

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    mpls ip

            4.    interface type number

            5.    mpls ip

            6.    exit


          DETAILED STEPS
             Command or ActionPurpose
            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 mpls ip


            Example:
            Router(config)# mpls ip
             
            
             

            Enables MPLS encapsulation for the router.

             
            Step 4 interface type number


            Example:
            Router(config)# interface Ethernet5/0
             

            (Optional) Specifies the interface to configure and enters interface configuration mode.

            • The type argument specifies the type of interface to be configured.
            • The number argument specifies the port, connector, or interface card number.
             
            Step 5 mpls ip


            Example:
            Router(config-if)# mpls ip
             
            
             

            (Optional) Enables MPLS encapsulation for the specified interface.

             
            Step 6 exit


            Example:
            Router(config-if)# exit
             

            (Optional) Exits to privileged EXEC mode.

             

            Verifying the Carrier Supporting Carrier Configuration

            The following commands verify the status of LDP sessions that were configured between the backbone carrier and customer carrier. Now the customer carrier ISP sites appear as a VPN customer to the backbone carrier.

            SUMMARY STEPS

              1.    show mpls ldp discovery vrf vrf-name

              2.    show mpls ldp discovery all


            DETAILED STEPS
              Step 1   show mpls ldp discovery vrf vrf-name

              Use this command to show that the LDP sessions are in VRF VPN1 of the PE router of the backbone carrier, for example:



              Example:
              Router# show mpls ldp discovery vrf vpn1 
              Local LDP Identifier:
                  10.0.0.0:0
              Discovery Sources:
                  Interfaces:
                      Ethernet1/0 (ldp): xmit/recv
                          LDP Id: 10.0.0.1:0
              POS6/0 (ldp): xmit
              
              Step 2   show mpls ldp discovery all

              Use this command to list all LDP sessions in a router, for example:



              Example:
              Router# show mpls ldp discovery all
              Local LDP Identifier:
                  10.10.10.10:0
              Discovery Sources:
                  Interfaces:
                      Ethernet1/5 (ldp): xmit/recv
                          LDP Id: 10.5.5.5:0
              VRF vpn1: Local LDP Identifier:
                  10.0.0.1:0
              Discovery Sources:
                  Interfaces:
                      Ethernet1/0 (ldp): xmit/recv
                          LDP Id: 10.0.0.1:0
              POS6/0 (ldp): xmit
              

              The Local LDP Identifier field shows the LDP identifier for the local label switching router for this session. The Interfaces field displays the interfaces engaging in LDP discovery activity:

              • xmit indicates that the interface is transmitting LDP discovery hello packets.
              • recv indicates that the interface is receiving LDP discovery hello packets.

              Configuration Examples for MPLS VPN CSC with LDP and IGP

              MPLS VPN CSC Network with a Customer Who Is an ISP Example

              The figure below shows a carrier supporting carrier network configuration where the customer carrier is an ISP. The customer carrier has two sites, each of which is a POP. The customer carrier connects these sites using a VPN service provided by the backbone carrier. The backbone carrier uses MPLS. The ISP sites use IP. To enable packet transfer between the ISP sites and the backbone carrier, the CE routers that connect the ISPs to the backbone carrier run MPLS.

              Figure 6. Carrier Supporting Carrier Network with a Customer Carrier Who Is an ISP

              The following examples show the configuration of each router in the carrier supporting carrier network. OSPF is used to connect the customer carrier to the backbone carrier.

              CSC-CE1 Configuration

              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.14.14.14 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 101 0 51 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM2/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM2/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               network 10.14.14.14 0.0.0.0 area 200
               network 10.15.0.0 0.255.255.255 area 200
               network 10.16.0.0 0.255.255.255 area 200

              CSC-PE1 Configuration

              ip cef distributed
              !
              ip vrf vpn1
               rd 100:0
               route-target export 100:0
               route-target import 100:0
              mpls label protocol ldp
              no mpls aggregate-statistics
              !
              interface Loopback0
               ip address 10.11.11.11 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface Loopback100
               ip vrf forwarding vpn1
               ip address 10.19.19.19 255.255.255.255
               no ip directed-broadcast
              !
              interface ATM1/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/1/0.1 
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 101 0 51 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 100
               log-adjacency-changes
               passive-interface ATM3/0/0.1
               passive-interface Loopback100
               network 10.11.11.11 0.0.0.0 area 100
               network 10.0.0.0 0.255.255.255 area 100
              !
              router ospf 200 vrf vpn1
               log-adjacency-changes
               redistribute bgp 100 metric-type 1 subnets
               network 10.19.19.19 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 100
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.12.12.12 remote-as 100
               neighbor 10.12.12.12 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.12.12.12 activate
               neighbor 10.12.12.12 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.12.12.12 activate
               neighbor 10.12.12.12 send-community extended
               exit-address-family
               !
               address-family ipv4 vrf vpn1
               redistribute ospf 200 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family

              CSC-PE2 Configuration

              ip cef distributed
              !
              ip vrf vpn1
               rd 100:0
               route-target export 100:0
               route-target import 100:0
              mpls label protocol ldp
              no mpls aggregate-statistics
              !
              interface Loopback0
               ip address 10.12.12.12 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface Loopback100
               ip vrf forwarding vpn1
               ip address 10.20.20.20 255.255.255.255
               no ip directed-broadcast
              !
              interface ATM0/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM0/1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 100
               log-adjacency-changes
               passive-interface ATM3/0/0.1
               passive-interface Loopback100
               network 10.12.12.12 0.0.0.0 area 100
               network 10.0.0.0 0.255.255.255 area 100
              !
              router ospf 200 vrf vpn1
               log-adjacency-changes
               redistribute bgp 100 metric-type 1 subnets
               network 10.20.20.20 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 100
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.11.11.11 remote-as 100
               neighbor 10.11.11.11 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.11.11.11 activate
               neighbor 10.11.11.11 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.11.11.11 activate
               neighbor 10.11.11.11 send-community extended
               exit-address-family
               !
               address-family ipv4 vrf vpn1
               redistribute ospf 200 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family

              CSC-CE2 Configuration

              ip cef
              !         
              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.16.16.16 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               network 10.16.16.16 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
               network 10.0.0.0 0.255.255.255 area 200

              MPLS VPN CSC Network with a Customer Who Is an MPLS VPN Provider Example

              The figure below shows a carrier supporting carrier network configuration where the customer carrier is an MPLS VPN provider. The customer carrier has two sites. The backbone carrier and the customer carrier use MPLS. The IBGP sessions exchange the external routing information of the ISP.

              Figure 7. Carrier Supporting Carrier Network with a Customer Carrier Who Is an MPLS VPN Provider

              The following configuration examples show the configuration of each router in the carrier supporting carrier network. OSPF is the protocol used to connect the customer carrier to the backbone carrier.

              CE1 Configuration

              ip cef
              !
              interface Loopback0
               ip address 10.17.17.17 255.255.255.255
               no ip directed-broadcast
              !
              interface Ethernet0/1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !
              router ospf 300
               log-adjacency-changes
               redistribute bgp 300 subnets
               passive-interface Ethernet0/1
               network 10.17.17.17 0.0.0.0 area 300
              !
              router bgp 300
               no synchronization
               bgp log-neighbor-changes
               timers bgp 10 30
               redistribute connected
               redistribute ospf 300 match internal external 1 external 2
               neighbor 10.0.0.1 remote-as 200
               neighbor 10.0.0.1 advertisement-interval 5
               no auto-summary

              PE1 Configuration

              ip cef
              !         
              ip vrf vpn2
               rd 200:1
               route-target export 200:1
               route-target import 200:1
              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.13.13.13 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface Ethernet3/0
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               passive-interface Ethernet3/0
               network 10.13.13.13 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 200
               no bgp default ipv4-unicast
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.15.15.15 remote-as 200
               neighbor 10.15.15.15 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.15.15.15 activate
               neighbor 10.15.15.15 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.15.15.15 activate
               neighbor 10.15.15.15 send-community extended
               exit-address-family
               !        
               address-family ipv4 vrf vpn2
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               neighbor 10.0.0.2 advertisement-interval 5
               no auto-summary
               no synchronization
               exit-address-family

              CSC-CE1 Configuration

              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.14.14.14 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 101 0 51 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM2/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM2/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               network 10.14.14.14 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
               network 10.0.0.0 0.255.255.255 area 200

              CSC-PE1 Configuration

              ip cef distributed
              !
              ip vrf vpn1
               rd 100:0
               route-target export 100:0
               route-target import 100:0
              mpls label protocol ldp
              no mpls aggregate-statistics
              !
              interface Loopback0
               ip address 11.11.11.11 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface Loopback100
               ip vrf forwarding vpn1
               ip address 10.19.19.19 255.255.255.255
               no ip directed-broadcast
              !
              interface ATM1/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/1/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 101 0 51 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 100
               log-adjacency-changes
               passive-interface ATM3/0/0.1
               passive-interface Loopback100
               network 10.11.11.11 0.0.0.0 area 100
               network 10.0.0.0 0.255.255.255 area 100
              !
              router ospf 200 vrf vpn1
               log-adjacency-changes
               redistribute bgp 100 metric-type 1 subnets
               network 10.19.19.19 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 100
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.12.12.12 remote-as 100
               neighbor 10.12.12.12 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.12.12.12 activate
               neighbor 10.12.12.12 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.12.12.12 activate
               neighbor 10.12.12.12 send-community extended
               exit-address-family
               !
               address-family ipv4 vrf vpn1
               redistribute ospf 200 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family

              CSC-PE2 Configuration

              ip cef distributed
              !
              ip vrf vpn1
               rd 100:0
               route-target export 100:0
               route-target import 100:0
              mpls label protocol ldp
              no mpls aggregate-statistics
              !
              interface Loopback0
               ip address 10.12.12.12 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface Loopback100
               ip vrf forwarding vpn1
               ip address 10.20.20.20 255.255.255.255
               no ip directed-broadcast
              !
              interface ATM0/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM0/1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 100
               log-adjacency-changes
               passive-interface ATM3/0/0.1
               passive-interface Loopback100
               network 10.12.12.12 0.0.0.0 area 100
               network 10.0.0.0 0.255.255.255 area 100
              !
              router ospf 200 vrf vpn1
               log-adjacency-changes
               redistribute bgp 100 metric-type 1 subnets
               network 10.20.20.20 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 100
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.11.11.11 remote-as 100
               neighbor 10.11.11.11 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.11.11.11 activate
               neighbor 10.11.11.11 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.11.11.11 activate
               neighbor 10.11.11.11 send-community extended
               exit-address-family
               !
               address-family ipv4 vrf vpn1
               redistribute ospf 200 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family

              CSC-CE2 Configuration

              ip cef
              !         
              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.16.16.16 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               network 10.16.16.16 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
               network 10.0.0.0 0.255.255.255 area 200

              PE2 Configuration

              ip cef
              ip cef accounting non-recursive 
              !         
              ip vrf vpn2
               rd 200:1
               route-target export 200:1
               route-target import 200:1
              mpls label protocol ldp
              !
              interface Loopback0
               ip address 10.15.15.15 255.255.255.255
               no ip directed-broadcast
              !
              interface Ethernet3/0
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
              !
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !
              router ospf 200
               log-adjacency-changes
               redistribute connected subnets
               passive-interface Ethernet3/0
               network 10.15.15.15 0.0.0.0 area 200
               network 10.0.0.0 0.255.255.255 area 200
              !
              router bgp 200
               no bgp default ipv4-unicast
               bgp log-neighbor-changes
               timers bgp 10 30
               neighbor 10.13.13.13 remote-as 200
               neighbor 10.13.13.13 update-source Loopback0
               !
               address-family ipv4
               neighbor 10.13.13.13 activate
               neighbor 10.13.13.13 send-community extended
               no synchronization
               exit-address-family
               !
               address-family vpnv4
               neighbor 10.13.13.13 activate
               neighbor 10.13.13.13 send-community extended
               exit-address-family
               !
               address-family ipv4 vrf vpn2
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               neighbor 10.0.0.2 advertisement-interval 5
               no auto-summary
               no synchronization
               exit-address-family

              CE2 Configuration

              ip cef
              !
              interface Loopback0
               ip address 10.18.18.18 255.255.255.255
               no ip directed-broadcast
              !
              interface Ethernet0/1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !
              router ospf 300
               log-adjacency-changes
               redistribute bgp 300 subnets
               passive-interface Ethernet0/1
               network 10.18.18.18 0.0.0.0 area 300
              !
              router bgp 300
               no synchronization
               bgp log-neighbor-changes
               timers bgp 10 30
               redistribute connected
               redistribute ospf 300 match internal external 1 external 2
               neighbor 10.0.0.1 remote-as 200
               neighbor 10.0.0.1 advertisement-interval 5
               no auto-summary

              MPLS VPN CSC Network That Contains Route Reflectors Example

              The figure below shows a carrier supporting carrier network configuration that contains route reflectors. The customer carrier has two sites.

              Figure 8. Carrier Supporting Carrier Network that Contains Route Reflectors


              Note


              A connection between route reflectors (RRs) is not necessary.


              The following configuration examples show the configuration of each router in the carrier supporting carrier network. Note the following:

              • The router IP addresses are abbreviated for ease of reading. For example, the loopback address for PE 1 is 25, which is equivalent to 10.25.25.25.
              • The following list shows the loopback addresses for the CSC-PE routers:
                • CSC-PE1 (75K-37-3): loopback 0 = 10.15.15.15, loopback 1 = 10.18.18.18
                • CSC-PE2 (75K-38-3): loopback 0 = 10.16.16.16, loopback 1 = 10.20.20.20

              Backbone Carrier Configuration

              Route Reflector 1 (72K-37-1) Configuration
              interface Loopback0
               ip address 10.13.13.13 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM1/0.1 mpls
              ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              interface ATM1/1
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM1/1.1 mpls
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              router ospf 100
               auto-cost reference-bandwidth 10000
               network 10.0.0.0 0.255.255.255 area 100
               network 10.1.0.0 0.255.255.255 area 100
               network 10.2.0.0 0.255.255.255 area 100
              !         
              router bgp 100
               no synchronization
               no bgp default ipv4-unicast
               bgp cluster-id 1
               redistribute static
               neighbor 10.15.15.15 remote-as 100
               neighbor 10.15.15.15 update-source Loopback0
               neighbor 10.16.16.16 remote-as 100
               neighbor 10.16.16.16 update-source Loopback0
               !        
               address-family ipv4 vrf vpn1
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.15.15.15 activate
               neighbor 10.15.15.15 route-reflector-client
               neighbor 10.15.15.15 send-community extended
               neighbor 10.16.16.16 activate
               neighbor 10.16.16.16 route-reflector-client
               neighbor 10.16.16.16 send-community extended
               bgp scan-time import 5
               exit-address-family
              Route Reflector 2 (72K-38-1) Configuration
              interface Loopback0
               ip address 10.14.14.14 255.255.255.255
               no ip directed-broadcast
               no ip mroute-cache
              !         
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM1/0.1 mpls
               ip address 10.0.0.1 255.0.0.0
              no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              interface ATM1/1
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM1/1.1 mpls
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              router ospf 100
               auto-cost reference-bandwidth 10000
               network 10.0.0.0 0.255.255.255 area 100
               network 10.1.0 0.255.255.255 area 100
               network 10.2.0.0 0.255.255.255 area 100
              !         
              router bgp 100
               no synchronization
               no bgp default ipv4-unicast
               bgp cluster-id 1
               redistribute static
               neighbor 10.15.15.15 remote-as 100
               neighbor 10.15.15.15 update-source Loopback0
               neighbor 10.16.16.16 remote-as 100
               neighbor 10.16.16.16 update-source Loopback0
               !        
               address-family ipv4 vrf vpn1
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.15.15.15 activate
               neighbor 10.15.15.15 route-reflector-client
               neighbor 10.15.15.15 send-community extended
               neighbor 10.16.16.16 activate
               neighbor 10.16.16.16 route-reflector-client
               neighbor 10.16.16.16 send-community extended
               bgp scan-time import 5
               exit-address-family
              CSC-PE1 (75K-37-3) Configuration
              ip cef distributed
              !         
              ip vrf vpn1
               rd 100:1 
               route-target export 100:1
               route-target import 100:1
              !         
              interface Loopback0
               ip address 10.15.15.15 255.255.255.255
               no ip directed-broadcast
              !         
              interface Loopback1
               ip vrf forwarding vpn1
               ip address 10.18.18.18 255.255.255.255
               no ip directed-broadcast
              !         
              interface Ethernet0/0/1
               ip vrf forwarding vpn1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip route-cache distributed
               mpls label protocol ldp
               mpls ip
              !         
              interface ATM1/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM1/1/0.1 mpls
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 6 32 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !         
              interface ATM3/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM3/1/0.1 mpls
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              router ospf 100
               auto-cost reference-bandwidth 10000
               network 10.0.0.0 0.255.255.255 area 100
               network 10.1.0.0 0.255.255.255 area 100
               network 10.2.0.0 0.255.255.255 area 100
               network 10.3.0.0 0.255.255.255 area 100
               network 10.4.0.0 0.255.255.255 area 100
              !         
              router ospf 1 vrf vpn1
               redistribute bgp 100 metric-type 1 subnets
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              !         
              router bgp 100
               no bgp default ipv4-unicast
               bgp log-neighbor-changes
               neighbor 10.13.13.13 remote-as 100
               neighbor 10.13.13.13 update-source Loopback0
               neighbor 10.14.14.14 remote-as 100
               neighbor 10.14.14.14 update-source Loopback0
               !        
               address-family ipv4
               redistribute static
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.13.13.13 activate
               neighbor 10.13.13.13 send-community extended
               neighbor 10.14.14.14 activate
               neighbor 10.14.14.14 send-community extended
               exit-address-family
               !        
               address-family ipv4 vrf vpn1
               redistribute ospf 1 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family
              CSC-PE2 (75K-38-3) Configuration
              ip cef distributed
              !         
              ip vrf vpn1
               rd 100:1 
               route-target export 100:1
               route-target import 100:1
              !         
              interface Loopback0
               ip address 10.16.16.16 255.255.255.255
               no ip directed-broadcast
              !         
              interface Loopback1
               ip vrf forwarding vpn1
               ip address 10.20.20.20 255.255.255.255
               no ip directed-broadcast
              !         
              interface ATM0/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
              atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM0/1/0.1 mpls
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              interface ATM2/1/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM2/1/0.1 mpls
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls atm vpi 2-5
               mpls ip
              !         
              interface ATM3/0/0
               no ip address
               no ip directed-broadcast
               no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM3/0/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 6 32 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !         
              interface ATM3/1/0
               no ip address
               no ip directed-broadcast
              no ip route-cache distributed
               atm clock INTERNAL
               atm sonet stm-1
               no atm enable-ilmi-trap
               no atm ilmi-keepalive
              !         
              interface ATM3/1/0.1 point-to-point
               ip vrf forwarding vpn1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 101 6 33 aal5snap
               no atm enable-ilmi-trap
               mpls label protocol ldp
               mpls ip
              !         
              router ospf 100
               auto-cost reference-bandwidth 10000
               network 10.0.0.0 0.255.255.255 area 100
               network 10.0.0.0 0.255.255.255 area 100
               network 10.0.0.0 0.255.255.255 area 100
               network 10.0.0.0 0.255.255.255 area 100
               network 10.0.0.0 0.255.255.255 area 100
              !         
              router ospf 1 vrf vpn1
               redistribute bgp 100 metric-type 1 subnets
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              !         
              router bgp 100
               no bgp default ipv4-unicast
               bgp log-neighbor-changes
               neighbor 10.13.13.13 remote-as 100
               neighbor 10.13.13.13 update-source Loopback0
               neighbor 10.14.14.14 remote-as 100
               neighbor 10.14.14.14 update-source Loopback0
               !        
               address-family ipv4
               redistribute static
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.13.13.13 activate
               neighbor 10.13.13.13 send-community extended
               neighbor 10.14.14.14 activate
               neighbor 10.14.14.14 send-community extended
               exit-address-family
               !        
               address-family ipv4 vrf vpn1
               redistribute ospf 1 match internal external 1 external 2
               no auto-summary
               no synchronization
               exit-address-family

              Customer Carrier Site 1 Configuration

              PE1 (72K-36-8) Configuration
              ip cef
              !
              ip vrf vpn2
               rd 200:1 
               route-target export 200:1
               route-target import 200:1
              no mpls ip propagate-ttl
              !         
              interface Loopback0
               ip address 10.25.25.25 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
               mpls label protocol ldp
               mpls ip
              !         
              interface Ethernet3/0
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              !         
              interface Ethernet3/1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
               mpls label protocol ldp
               mpls ip
              !         
              interface Ethernet3/2
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               neighbor 10.22.22.22 remote-as 200
               neighbor 10.22.22.22 update-source Loopback0
               neighbor 10.23.23.23 remote-as 200
               neighbor 10.23.23.23 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               redistribute connected
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.22.22.22 activate
               neighbor 10.22.22.22 send-community extended
               neighbor 10.23.23.23 activate
               neighbor 10.23.23.23 send-community extended
               exit-address-family
              CSC-CE1 (72K-36-9) Configuration
              ip cef
              no ip domain-lookup
              !         
              interface Loopback0
               ip address 10.11.11.11 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 6 32 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              interface ATM2/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM2/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 50 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/0
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/1
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              PE2 (72K-36-7) Configuration
              ip cef
              !
              ip vrf vpn2
               rd 200:1 
               route-target export 200:1
               route-target import 200:1
              no mpls ip propagate-ttl
              !         
              interface Loopback0
               ip address 10.24.24.24 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface Ethernet3/0
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/1
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              !         
              interface Ethernet3/2
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/3
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               neighbor 10.22.22.22 remote-as 200
               neighbor 10.22.22.22 update-source Loopback0
               neighbor 10.23.23.23 remote-as 200
               neighbor 10.23.23.23 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.22.22.22 activate
               neighbor 10.22.22.22 send-community extended
               neighbor 10.23.23.23 activate
               neighbor 10.23.23.23 send-community extended
               exit-address-family
              Route Reflector 3 (36K-38-4) Configuration
              ip cef    
              !         
              interface Loopback0
               ip address 10.23.23.23 255.255.255.255
              !         
              interface Ethernet1/1
               ip address 10.0.0.1 255.0.0.0
               mpls label protocol ldp
               mpls ip
              !         
              interface Ethernet1/2
               ip address 10.0.0.1 255.0.0.0
               mpls label protocol ldp
               mpls ip
              !         
              interface ATM3/0
               no ip address
               no ip mroute-cache
               atm clock INTERNAL
               no atm scrambling cell-payload
               no atm ilmi-keepalive
              !         
              interface ATM3/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               atm pvc 100 0 55 aal5snap
               mpls label protocol ldp
               mpls ip
              !         
              router ospf 1
               log-adjacency-changes
               network 10.0.0.0 0.255.255.255 area 101
               network 10.1.0.0 0.255.255.255 area 101
               network 10.2.0.0 0.255.255.255 area 101
               network 10.3.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               no synchronization
               no bgp default ipv4-unicast
               bgp cluster-id 2
               redistribute static
               neighbor 10.21.21.21 remote-as 200
               neighbor 10.21.21.21 update-source Loopback0
               neighbor 10.24.24.24 remote-as 200
               neighbor 10.24.24.24 update-source Loopback0
               neighbor 10.25.25.25 remote-as 200
               neighbor 10.25.25.25 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.21.21.21 activate
               neighbor 10.21.21.21 route-reflector-client
               neighbor 10.21.21.21 send-community extended
               neighbor 10.24.24.24 activate
               neighbor 10.24.24.24 route-reflector-client
               neighbor 10.24.24.24 send-community extended
               neighbor 10.25.25.25 activate
               neighbor 10.25.25.25 route-reflector-client
               neighbor 10.25.25.25 send-community extended
               exit-address-family
              CE1 (36K-36-1) Configuration
              ip cef
              !         
              interface Loopback0
               ip address 10.28.28.28 255.255.255.255
               no ip directed-broadcast
              !         
              interface Ethernet0/1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !         
              interface Ethernet0/2
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !         
              router bgp 300
               network 10.0.0.0
               network 10.0.0.0
               network 10.0.0.0
               neighbor 10.0.0.1 remote-as 200
               neighbor 10.0.0.1 remote-as 200

              Customer Carrier Site 2 Configuration

              CSC-CE3 (72K-36-6) Configuration
              ip cef
              !         
              interface Loopback0
               ip address 10.12.12.12 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface ATM1/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM1/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 6 32 aal5snap
              mpls label protocol ldp
               mpls ip
              !         
              interface POS2/0
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               encapsulation ppp
              mpls label protocol ldp
              mpls ip
              !         
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               no ip mroute-cache
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 40 aal5snap
               mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.1.0.0 0.255.255.255 area 101
               network 10.2.0.0 0.255.255.255 area 101
               network 10.3.0.0 0.255.255.255 area 101
              PE3 (72K-36-4) Configuration
              ip cef
              !         
              ip vrf vpn2
               rd 200:1 
               route-target export 200:1
               route-target import 200:1
              !         
              ! 
              interface Loopback0
               ip address 10.21.21.21 255.255.255.255
               no ip directed-broadcast
              !         
              interface Ethernet3/0
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
              !         
              interface Ethernet3/1
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
              !         
              interface Ethernet3/2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
              mpls label protocol ldp
              mpls ip
              !         
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 40 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              interface ATM6/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM6/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 20 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.1.0.0 0.255.255.255 area 101
               network 10.2.0.0 0.255.255.255 area 101
               network 10.3.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               neighbor 10.22.22.22 remote-as 200
               neighbor 10.22.22.22 update-source Loopback0
               neighbor 10.23.23.23 remote-as 200
               neighbor 10.23.23.23 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               redistribute connected
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.22.22.22 activate
               neighbor 10.22.22.22 send-community extended
               neighbor 10.23.23.23 activate
               neighbor 10.23.23.23 send-community extended
               exit-address-family
              CSC-CE4 (72K-36-5) Configuration
              ip cef
              !         
              interface Loopback0
               ip address 10.10.10.10 255.255.255.255
               no ip directed-broadcast
              !         
              interface POS4/0
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               encapsulation ppp
              mpls label protocol ldp
              mpls ip
               clock source internal
              !         
              interface ATM5/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM5/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 0 20 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              interface ATM6/0
               no ip address
               no ip directed-broadcast
               atm clock INTERNAL
               no atm ilmi-keepalive
              !         
              interface ATM6/0.1 point-to-point
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               atm pvc 100 6 33 aal5snap
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.1.0.0 0.255.255.255 area 101
               network 10.2.0.0 0.255.255.255 area 101
               network 10.3.0.0 0.255.255.255 area 101
              Route Reflector 4 (36K-38-5) Configuration
              ip cef
              !         
              interface Loopback0
               ip address 10.22.22.22 255.255.255.255
              !         
              interface Ethernet0/1
               ip address 10.0.0.2 255.0.0.0
               mpls label protocol ldp
               mpls ip
              !         
              interface ATM2/0
               no ip address
               no ip mroute-cache
               atm clock INTERNAL
               no atm scrambling cell-payload
               no atm ilmi-keepalive
              !         
              interface ATM2/0.1 point-to-point
               ip address 10.0.0.1 255.0.0.0
               atm pvc 100 0 55 aal5snap
               mpls label protocol ldp
               mpls ip
              !         
              router ospf 1
               log-adjacency-changes
               network 10.0.0.0 0.255.255.255 area 101
               network 10.1.0.0 0.255.255.255 area 101
               network 10.2.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               no synchronization
               no bgp default ipv4-unicast
               bgp cluster-id 2
               redistribute static
               neighbor 10.21.21.21 remote-as 200
               neighbor 10.21.21.21 update-source Loopback0
               neighbor 10.24.24.24 remote-as 200
               neighbor 10.24.24.24 update-source Loopback0
               neighbor 10.25.25.25 remote-as 200
               neighbor 10.25.25.25 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.21.21.21 activate
               neighbor 10.21.21.21 route-reflector-client
               neighbor 10.21.21.21 send-community extended
               neighbor 10.24.24.24 activate
               neighbor 10.24.24.24 route-reflector-client
               neighbor 10.24.24.24 send-community extended
               neighbor 10.25.25.25 activate
               neighbor 10.25.25.25 route-reflector-client
               neighbor 10.25.25.25 send-community extended
               exit-address-family
              CE2 (36K-36-2) Configuration
              ip cef
              !
              interface Loopback0
               ip address 10.26.26.26 255.255.255.255
               no ip directed-broadcast
              !         
              interface Ethernet0/1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !         
              interface Ethernet0/2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
              !         
              router ospf 300
               redistribute bgp 300
               network 10.0.0.0 0.255.255.255 area 300
               network 10.0.0.0 0.255.255.255 area 300
              !         
              router bgp 300
               network 10.0.0.0
               network 10.1.0.0
               network 10.2.0.0
               neighbor 10.0.0.1 remote-as 200
              CE3 (36K-36-3) Configuration
              ip cef
              !         
              interface Loopback0
               ip address 10.27.27.27 255.255.255.255
               no ip directed-broadcast
              !         
              interface Ethernet1/1
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !         
              interface Ethernet1/2
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
              !         
              router ospf 300
               redistribute bgp 300
               network 10.0.0.0 0.255.255.255 area 300
               network 10.0.0.0 0.255.255.255 area 300
              !         
              router bgp 300
               network 10.0.0.0
               network 10.1.0.0
               network 10.2.0.0
               neighbor 10.0.0.1 remote-as 200
              

              MPLS VPN CSC Network with a Customer Who Has VPNs at the Network Edge Example

              The figure below shows a carrier supporting carrier network configuration where the customer carrier has VPNs at the network edge.

              Figure 9. Carrier Supporting Carrier Network

              Backbone Carrier Configuration

              CSC-PE1 (72K-36-9) Configuration
              ip cef 
              ! 
              ip vrf vpn1 
              rd 100:0 
              route-target export 100:0 
              route-target import 100:0 
              mpls label protocol ldp 
              ! 
              ! 
              interface Loopback0 
              ip address 10.14.14.14 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface Loopback100 
              ip vrf forwarding vpn1 
              ip address 10.22.22.22 255.255.255.255 
              no ip directed-broadcast 
              ! 
              interface ATM1/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM1/0.1 point-to-point 
              ip address 10.1.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/0.2 point-to-point 
              ip address 10.2.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/0.3 point-to-point 
              ip address 10.3.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM2/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM2/0.1 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.15.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM2/0.2 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.16.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM2/0.3 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.17.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 100 
              log-adjacency-changes 
              redistribute connected subnets 
              passive-interface ATM2/0.1 
              passive-interface ATM2/0.2 
              passive-interface ATM2/0.3 
              passive-interface Loopback100 
              network 10.14.14.14 0.0.0.0 area 100 
              network 10.1.0.0 0.0.255.255 area 100 
              network 10.2.0.0 0.0.255.255 area 100 
              network 10.3.0.0 0.0.255.255 area 100 
              ! 
              router ospf 200 vrf vpn1 
              log-adjacency-changes 
              redistribute connected subnets 
              redistribute bgp 100 metric-type 1 subnets 
              network 10.22.22.22 0.0.0.0 area 200 
              network 10.15.0.0 0.0.255.255 area 200 
              network 10.16.0.0 0.0.255.255 area 200 
              network 10.17.0.0 0.0.255.255 area 200 
              ! 
              router bgp 100 
              bgp log-neighbor-changes 
              timers bgp 10 30 
              neighbor 10.11.11.11 remote-as 100 
              neighbor 10.11.11.11 update-source Loopback0 
              ! 
              address-family ipv4 
              neighbor 10.11.11.11 activate 
              neighbor 10.11.11.11 send-community extended 
              no synchronization 
              exit-address-family 
              ! 
              address-family vpnv4 
              neighbor 10.11.11.11 activate 
              neighbor 10.11.11.11 send-community extended 
              exit-address-family 
              ! 
              address-family ipv4 vrf vpn1 
              redistribute ospf 200 match internal external 1 external 2 
              no auto-summary 
              no synchronization 
              exit-address-family 
              P1 (75K-37-3) Configuration
              ip cef distributed 
              ! 
              mpls label protocol ldp 
              ! 
              interface Loopback0 
              ip address 10.12.12.12 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface ATM1/1/0 
              no ip address 
              no ip directed-broadcast 
              ip route-cache distributed 
              atm clock INTERNAL 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM1/1/0.1 point-to-point 
              ip address 10.7.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 103 0 53 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/1/0.2 point-to-point 
              ip address 10.8.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 104 0 54 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/1/0.3 point-to-point 
              ip address 10.9.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 105 0 55 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM3/0/0 
              no ip address 
              no ip directed-broadcast 
              ip route-cache distributed 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM3/0/0.1 point-to-point 
              ip address 10.1.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              mpls accounting experimental input 
              tag-switching ip 
              ! 
              interface ATM3/0/0.2 point-to-point 
              ip address 10.2.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM3/0/0.3 point-to-point 
              ip address 10.3.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 100 
              log-adjacency-changes 
              redistribute connected subnets 
              network 10.12.12.12 0.0.0.0 area 100 
              network 10.1.0.0 0.0.255.255 area 100 
              network 10.2.0.0 0.0.255.255 area 100 
              network 10.3.0.0 0.0.255.255 area 100 
              network 10.7.0.0 0.0.255.255 area 100 
              network 10.8.0.0 0.0.255.255 area 100 
              network 10.9.0.0 0.0.255.255 area 100 
              P2 (75K-38-3) Configuration
              ip cef distributed 
              ! 
              mpls label protocol ldp 
              ! 
              interface Loopback0 
              ip address 10.13.13.13 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface ATM0/1/0 
              no ip address 
              no ip directed-broadcast 
              ip route-cache distributed 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM0/1/0.1 point-to-point 
              ip address 10.7.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 103 0 53 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM0/1/0.2 point-to-point 
              ip address 10.8.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 104 0 54 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM0/1/0.3 point-to-point 
              ip address 10.9.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 105 0 55 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM3/1/0 
              no ip address 
              no ip directed-broadcast 
              ip route-cache distributed 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM3/1/0.1 point-to-point 
              ip address 10.4.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM3/1/0.2 point-to-point 
              ip address 10.5.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM3/1/0.3 point-to-point 
              ip address 10.6.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 100 
              log-adjacency-changes 
              redistribute connected subnets 
              network 10.13.13.13 0.0.0.0 area 100 
              network 10.4.0.0 0.0.255.255 area 100 
              network 10.5.0.0 0.0.255.255 area 100 
              network 10.6.0.0 0.0.255.255 area 100 
              network 10.7.0.0 0.0.255.255 area 100 
              network 10.8.0.0 0.0.255.255 area 100 
              network 10.9.0.0 0.0.255.255 area 100 
              ! 
              CSC-PE2 (72K-36-5) Configuration
              ip cef 
              ! 
              ip vrf vpn1 
              rd 100:0 
              route-target export 100:0 
              route-target import 100:0 
              mpls label protocol ldp 
              ! 
              interface Loopback0 
              ip address 10.11.11.11 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface Loopback100 
              ip vrf forwarding vpn1 
              ip address 10.23.23.23 255.255.255.255 
              no ip directed-broadcast 
              ! 
              interface ATM5/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM5/0.1 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.18.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.2 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.19.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.3 point-to-point 
              ip vrf forwarding vpn1 
              ip address 10.20.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM6/0.1 point-to-point 
              ip address 10.4.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0.2 point-to-point 
              ip address 10.5.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0.3 point-to-point 
              ip address 10.6.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 100 
              log-adjacency-changes 
              redistribute connected subnets 
              passive-interface ATM5/0.1 
              passive-interface ATM5/0.2 
              passive-interface ATM5/0.3 
              passive-interface Loopback100 
              network 10.11.11.11 0.0.0.0 area 100 
              network 10.4.0.0 0.0.255.255 area 100 
              network 10.5.0.0 0.0.255.255 area 100 
              network 10.6.0.0 0.0.255.255 area 100 
              ! 
              router ospf 200 vrf vpn1 
              log-adjacency-changes 
              redistribute connected subnets 
              redistribute bgp 100 metric-type 1 subnets 
              network 10.23.23.23 0.0.0.0 area 200 
              network 10.18.0.0 0.0.255.255 area 200 
              network 10.19.0.0 0.0.255.255 area 200 
              network 10.20.0.0 0.0.255.255 area 200 
              ! 
              router bgp 100 
              bgp log-neighbor-changes 
              timers bgp 10 30 
              neighbor 10.14.14.14 remote-as 100 
              neighbor 10.14.14.14 update-source Loopback0 
              ! 
              address-family ipv4 
              neighbor 10.14.14.14 activate 
              neighbor 10.14.14.14 send-community extended 
              no synchronization 
              exit-address-family 
              ! 
              address-family vpnv4 
              neighbor 10.14.14.14 activate 
              neighbor 10.14.14.14 send-community extended 
              exit-address-family 
              ! 
              address-family ipv4 vrf vpn1 
              redistribute ospf 200 match internal external 1 external 2 
              no auto-summary 
              no synchronization 
              exit-address-family 

              Customer Carrier Site 1 Configuration

              CSC-CE1 (72K-36-8) Configuration
              ip cef 
              ! 
              mpls label protocol ldp 
              !
              interface Loopback0 
              ip address 10.15.15.15 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface ATM1/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM1/0.1 point-to-point 
              ip address 10.15.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/0.2 point-to-point 
              ip address 10.16.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM1/0.3 point-to-point 
              ip address 10.17.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface Ethernet3/1 
              ip address 10.10.0.2 255.255.0.0 
              no ip directed-broadcast 
              no ip mroute-cache 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 200 
              log-adjacency-changes 
              redistribute connected subnets 
              network 10.15.15.15 0.0.0.0 area 200 
              network 10.10.0.0 0.0.255.255 area 200 
              network 10.15.0.0 0.0.255.255 area 200 
              network 10.16.0.0 0.0.255.255 area 200 
              network 10.17.0.0 0.0.255.255 area 200 
              PE2 (72K-36-7) Configuration
              ip cef
              !
              ip vrf vpn2
               rd 200:1 
               route-target export 200:1
               route-target import 200:1
              no mpls ip propagate-ttl
              !         
              interface Loopback0
               ip address 10.24.24.24 255.255.255.255
               no ip directed-broadcast
               no ip route-cache
               no ip mroute-cache
              !         
              interface Ethernet3/0
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/1
               ip vrf forwarding vpn2
               ip address 10.0.0.1 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              !         
              interface Ethernet3/2
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              interface Ethernet3/3
               ip address 10.0.0.2 255.0.0.0
               no ip directed-broadcast
               no ip mroute-cache
              mpls label protocol ldp
              mpls ip
              !         
              router ospf 1
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
               network 10.0.0.0 0.255.255.255 area 101
              !         
              router bgp 200
               neighbor 10.22.22.22 remote-as 200
               neighbor 10.22.22.22 update-source Loopback0
               neighbor 10.23.23.23 remote-as 200
               neighbor 10.23.23.23 update-source Loopback0
               !        
               address-family ipv4 vrf vpn2
               neighbor 10.0.0.2 remote-as 300
               neighbor 10.0.0.2 activate
               neighbor 10.0.0.2 as-override
               no auto-summary
               no synchronization
               exit-address-family
               !        
               address-family vpnv4
               neighbor 10.22.22.22 activate
               neighbor 10.22.22.22 send-community extended
               neighbor 10.23.23.23 activate
               neighbor 10.23.23.23 send-community extended
               exit-address-family
              CE1 (36K-36-1) Configuration
              ip cef 
              ! 
              interface Loopback0 
              ip address 10.19.19.19 255.255.255.255 
              no ip directed-broadcast 
              ! 
              interface Ethernet0/2 
              ip address 30.35.0.1 255.255.0.0 
              no ip directed-broadcast 
              ! 
              router ospf 300 
              log-adjacency-changes 
              redistribute connected subnets 
              redistribute bgp 300 subnets 
              passive-interface Ethernet0/2 
              network 10.19.19.19 0.0.0.0 area 300 
              ! 
              router bgp 300 
              no synchronization 
              bgp log-neighbor-changes 
              timers bgp 10 30 
              redistribute connected 
              redistribute ospf 300 match internal external 1 external 2 
              neighbor 10.35.0.2 remote-as 200 
              neighbor 10.35.0.2 advertisement-interval 5 
              no auto-summary 

              Customer Carrier Site 2 Configuration

              CSC-CE2 (72K-36-4) Configuration
              ip cef 
              ! 
              mpls label protocol ldp 
              ! 
              interface Loopback0 
              ip address 10.17.17.17 255.255.255.255 
              no ip directed-broadcast 
              ! 
              interface ATM5/0 
              no ip address 
              no ip directed-broadcast 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM5/0.1 point-to-point 
              ip address 10.11.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.2 point-to-point 
              ip address 10.12.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.3 point-to-point 
              ip address 10.13.0.2 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0 
              no ip address 
              no ip directed-broadcast 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM6/0.1 point-to-point 
              ip address 10.18.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0.2 point-to-point 
              ip address 10.19.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM6/0.3 point-to-point 
              ip address 10.20.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 200 
              log-adjacency-changes 
              redistribute connected subnets 
              network 10.17.17.17 0.0.0.0 area 200 
              network 10.11.0.0 0.0.255.255 area 200 
              network 10.12.0.0 0.0.255.255 area 200 
              network 10.13.0.0 0.0.255.255 area 200 
              network 10.18.0.0 0.0.255.255 area 200 
              network 10.19.0.0 0.0.255.255 area 200 
              network 10.20.0.0 0.0.255.255 area 200 
              PE2 (72K-36-6) Configuration
              ip cef 
              ! 
              ip vrf customersite 
              rd 200:1 
              route-target export 200:1 
              route-target import 200:1 
              mpls label protocol ldp 
              ! 
              interface Loopback0 
              ip address 10.18.18.18 255.255.255.255 
              no ip directed-broadcast 
              no ip route-cache 
              no ip mroute-cache 
              ! 
              interface Ethernet3/0 
              ip vrf forwarding customersite 
              ip address 10.29.0.2 255.255.0.0 
              no ip directed-broadcast 
              ! 
              interface Ethernet3/1 
              ip vrf forwarding customersite 
              ip address 10.30.0.2 255.255.0.0 
              no ip directed-broadcast 
              ! 
              interface ATM5/0 
              no ip address 
              no ip directed-broadcast 
              no ip mroute-cache 
              atm clock INTERNAL 
              atm sonet stm-1 
              no atm enable-ilmi-trap 
              no atm ilmi-keepalive 
              ! 
              interface ATM5/0.1 point-to-point 
              ip address 10.11.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 100 0 50 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.2 point-to-point 
              ip address 10.12.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 101 0 51 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              interface ATM5/0.3 point-to-point 
              ip address 10.13.0.1 255.255.0.0 
              no ip directed-broadcast 
              atm pvc 102 0 52 aal5snap 
              no atm enable-ilmi-trap 
              mpls label protocol ldp 
              tag-switching ip 
              ! 
              router ospf 200 
              log-adjacency-changes 
              redistribute connected subnets 
              passive-interface Ethernet3/0 
              passive-interface Ethernet3/1 
              network 10.18.18.18 0.0.0.0 area 200 
              network 10.11.0.0 0.0.255.255 area 200 
              network 10.12.0.0 0.0.255.255 area 200 
              network 10.13.0.0 0.0.255.255 area 200 
              ! 
              router bgp 200 
              no bgp default ipv4-unicast 
              bgp log-neighbor-changes 
              timers bgp 10 30 
              neighbor 10.16.16.16 remote-as 200 
              neighbor 10.16.16.16 update-source Loopback0 
              ! 
              address-family ipv4 
              neighbor 10.16.16.16 activate 
              neighbor 10.16.16.16 send-community extended 
              no synchronization 
              exit-address-family 
              ! 
              address-family vpnv4 
              neighbor 10.16.16.16 activate 
              neighbor 10.16.16.16 send-community extended 
              exit-address-family 
              ! 
              address-family ipv4 vrf customersite 
              neighbor 10.29.0.1 remote-as 300 
              neighbor 10.29.0.1 activate 
              neighbor 10.29.0.1 as-override 
              neighbor 10.29.0.1 advertisement-interval 5 
              neighbor 10.30.0.1 remote-as 300 
              neighbor 10.30.0.1 activate 
              neighbor 10.30.0.1 as-override 
              neighbor 10.30.0.1 advertisement-interval 5 
              no auto-summary 
              no synchronization 
              exit-address-family 
              CE2 (36K-38-4) Configuration
              ip cef 
              ! 
              interface Loopback0 
              ip address 10.21.21.21 255.255.255.255 
              ! 
              interface Ethernet1/3 
              ip address 10.29.0.1 255.255.0.0 
              ! 
              interface Ethernet5/0 
              ip address 10.14.0.1 255.255.0.0 
              ! 
              router ospf 300 
              log-adjacency-changes 
              redistribute connected subnets 
              redistribute bgp 300 subnets 
              passive-interface Ethernet1/3 
              network 10.21.21.21 0.0.0.0 area 300 
              network 10.14.0.0 0.0.255.255 area 300 
              ! 
              router bgp 300 
              no synchronization 
              timers bgp 10 30 
              redistribute connected 
              redistribute ospf 300 match internal external 1 external 2 
              neighbor 10.29.0.2 remote-as 200 
              neighbor 10.29.0.2 advertisement-interval 5 
              no auto-summary 
              CE3 (36K-38-5) Configuration
              ip cef 
              ! 
              interface Loopback0 
              ip address 10.20.20.20 255.255.255.255 
              no ip directed-broadcast 
              ! 
              interface Ethernet0/2 
              ip address 10.30.0.1 255.255.0.0 
              no ip directed-broadcast 
              ! 
              interface Ethernet0/3 
              ip address 10.14.0.2 255.255.0.0 
              no ip directed-broadcast 
              ! 
              router ospf 300 
              log-adjacency-changes 
              redistribute connected subnets 
              redistribute bgp 300 subnets 
              passive-interface Ethernet0/2 
              network 10.20.20.20 0.0.0.0 area 300 
              network 10.14.0.0 0.0.255.255 area 300 
              ! 
              router bgp 300 
              no synchronization 
              bgp log-neighbor-changes 
              timers bgp 10 30 
              redistribute connected 
              redistribute ospf 300 match internal external 1 external 2 
              neighbor 10.30.0.2 remote-as 200 
              neighbor 10.30.0.2 advertisement-interval 5 
              no auto-summary 

              Additional References for MPLS VPN Carrier Supporting Carrier Using LDP and an IGP

              Related Documents

              Related Topic

              Document Title

              MPLS

              MPLS Product Literature

              RFCs

              RFC

              Title

              RFC 2547

              BGP/MPLS VPNs

              Technical Assistance

              Description

              Link

              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 VPN CSC with LDP and IGP

              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 4 Feature Information for MPLS VPN CSC with LDP and IGP

              Feature Name

              Releases

              Feature Configuration Information

              MPLS VPN Carrier Supporting Carrier

              12.0(14)ST

              12.0(16)ST

              12.2(8)T

              12.0(21)ST

              12.0(22)S

              12.0(23)S

              Cisco IOS XE Release 2.2

              This feature enables you to set up and create an MPLS VPN CSC network that uses LDP to transport MPLS labels and an IGP to transport routes.

              In 12.0(14)ST, this feature was introduced.

              In 12.0(16)ST, this feature was integrated.

              In 12.2(8)T, this feature was integrated.

              In 12.0(21)ST, this feature was integrated.

              In 12.0(22)S, this feature was integrated.

              In 12.0(23)S, this feature was integrated.

              In Cisco IOS XE Release 2.2, this feature was implemented on the Cisco ASR 1000 Series Routers.

              This feature uses no new or modified commands.

              Glossary

              ASBR -- Autonomous System Boundary router. A router that connects one autonomous system to another.

              autonomous system --A collection of networks under a common administration sharing a common routing strategy.

              BGP --Border Gateway Protocol. An interdomain routing protocol that exchanges network reachability information with other BGP systems (which may be within the same autonomous system or between multiple autonomous systems).

              CE router--customer edge router. A router that is part of a customer network and that interfaces to a provider edge (PE) router. CE routers do not recognize associated MPLS VPNs.

              CSC --Carrier Supporting Carrier. A hierarchical VPN model that allows small service providers, or customer carriers, to interconnect their IP or MPLS networks over an MPLS backbone. This eliminates the need for customer carriers to build and maintain their own MPLS backbone.

              eBGP --external Border Gateway Protocol. A BGP between routers located within different autonomous systems. When two routers, located in different autonomous systems, are more than one hop away from one another, the eBGP session between the two routers is considered a multihop BGP.

              edge router--A router that is at the edge of the network. It defines the boundary of the MPLS network. It receives and transmits packets. Also referred to as edge label switch router and label edge router.

              iBGP --internal Border Gateway Protocol. A BGP between routers within the same autonomous system.

              IGP --Interior Gateway Protocol. Internet protocol used to exchange routing information within a single autonomous system. Examples of common Internet IGP protocols include IGRP, OSPF, IS-IS, and RIP.

              IP --Internet Protocol. Network layer protocol in the TCP/IP stack offering a connectionless internetwork service. IP provides features for addressing, type-of-service specification, fragmentation and reassembly, and security. Defined in RFC 791.

              LDP --Label Distribution Protocol. A standard protocol between MPLS-enabled routers to negotiate the labels (addresses) used to forward packets.

              LFIB --Label Forwarding Information Base. Data structure used in MPLS to hold information about incoming and outgoing labels and associated Forwarding Equivalence Class (FEC) packets.

              MP-BGP --Multiprotocol BGP.

              MPLS --Multiprotocol Label Switching. The name of the IETF working group responsible for label switching, and the name of the label switching approach it has standardized.

              NLRI --Network Layer Reachability Information. The BGP sends routing update messages containing NLRI to describe a route and how to get there. In this context, an NLRI is a prefix. A BGP update message carries one or more NLRI prefixes and the attributes of a route for the NLRI prefixes; the route attributes include a BGP next hop gateway address and extended community values.

              NSF --Nonstop forwarding enables routers to continuously forward IP packets following a Route Processor takeover or switchover to another Route Processor. NSF maintains and updates Layer 3 routing and forwarding information in the backup Route Processor to ensure that IP packets and routing protocol information are forwarded continuously during the switchover and route convergence process.

              PE router--provider edge router. A router that is part of a service provider’s network. It is connected to a customer edge (CE) router. All MPLS VPN processing occurs in the PE router.

              QoS --quality of service. Measure of performance for a transmission system that indicates its transmission quality and service availability.

              RD --route distinguisher. An 8-byte value that is concatenated with an IPv4 prefix to create a unique VPN-IPv4 prefix.

              RT --route target. Extended community attribute used to identify the VRF routing table into which a prefix is imported.

              SLA --Service Level Agreement given to VPN subscribers.

              VPN --Virtual Private Network. A secure MPLS-based network that shares resources on one or more physical networks (typically implemented by one or more service providers). A VPN contains geographically dispersed sites that can communicate securely over a shared backbone network.

              VRF --VPN routing and forwarding instance. Routing information that defines a VPN site that is attached to a PE router. A VRF consists of an IP routing table, a derived forwarding table, a set of interfaces that use the forwarding table, and a set of rules and routing protocols that determine what goes into the forwarding table.