Configuring MPLS VPN InterAS Options

Information About MPLS VPN InterAS Options

The MPLS VPN InterAS Options provide various ways of interconnecting VPNs between different MPLS VPN service providers. This allows sites of a customer to exist on several carrier networks (autonomous systems) and have seamless VPN connectivity between these sites.

ASes and ASBRs

An autonomous system (AS) is a single network or group of networks that is controlled by a common system administration group and using a single, clearly defined protocol. In many cases, VPNs extend to different ASes in different geographical areas. Some VPNs must extend across multiple service providers; these VPNs are called overlapping VPNs. The connection between ASes must be seamless to the customer, regardless of the complexity or location of the VPNs.

An AS boundary router (ASBR) is a device in an AS that is connected by using more than one routing protocol, and exchanges routing information with other ASBRs by using an exterior routing protocol (for example, eBGP), or use static routes, or both.

Separate ASes from different service providers communicate by exchanging information in the form of VPN IP addresses and they use the following protocols to share routing information:

  • Within an AS, routing information is shared using iBGP.

    iBGP distributes network layer information for IP prefixes within each VPN and each AS.

  • Between ASes, routing information is shared using eBGP.

    eBGP allows service providers to set up an interdomain routing system that guarantees loop-free exchange of routing information between separate ASes. The primary function of eBGP is to exchange network reachability information between ASes, including information about the list of AS routes. The ASes use eBGP border edge routers to distribute the routes, which includes label-switching information. Each border edge router rewrites the next-hop and MPLS labels.

MPLS VPN InterAS Options configuration is supported and can include an inter provider VPN, which is MPLS VPNs that include two or more ASes, connected by separate border edge routers. The ASes exchange routes using eBGP, and no iBGP or routing information is exchanged between the ASes.

MPLS VPN InterAS Options

The following options defined in RFC4364 provide MPLS VPN connectivity between different ASes:

  • InterAS Option A – This option provides back-to-back virtual routing and forwarding (VRF) connectivity. Here, MPLS VPN providers exchange routes across VRF interfaces.

  • InterAS Option B – This option provides VPNv4 route distribution between ASBRs.

InterAS Option A

In terms of configuration, interAS Option A is the simplest of all available options.

A typical AS consists of these devices – Provider Edge(PE), Customer Edge(CE) and an Autonomous System Boundary Router(ASBR). The target is to enable VRF connectivity between CE devices (also referred to as VPN sites) in a network. In order to facilitate interAS option A, you have to perform the following for each VPN site:

  • Assign a VRF interface to each VPN site

  • Define an interface or sub-interface for each VRF interface. (If multiple VPN sites are involved, they cannot all be associated with a single interface, and therefore, a sub-interface must be configured for each VRF). Optionally, a dedicated QoS policy may be applied to each subinterface.

  • Create a BGP (or other routing protocol) session for each VRF.

With the above configuration in place, traffic flow with option A is as follows: Within the AS, data packets travel like regular Layer 3 VPN traffic. Traffic flow between ASBRs when traversing ASes is in the form of unlabeled IP packets on a VRF interface. Any routing protocol may be used to exchange routing information between the ASBRs in the different ASes.

While this option provides certain advantages (flexibility in terms of the routing protocol that can be used within an AS and between ASBRs, and security by means of a QoS policy on a subinterface), the scale for interAS option A is limited by the scale numbers for subinterfaces and VRFs. This option is therefore suited only to scenarios where the number of VPNs and the number of routes to transfer, is limited (and not likely to increase).

The figure below shows the data packet flow from CE 1, CE 2, CE 3 to CE 4, CE 5, CE 6 respectively. The explanation below takes the instance of the route advertisement and data packet flow from CE1 in AS-65001 to CE 4 in AS-65002.

Figure 1. MPLS VPN InterAS Option A Topology

The IP traffic between CE 1 and PE 1 is sent over a VRF sub-interface by using eBGP. Once the packet reaches PE 1 it is sent to ASBR 1 as a two-label MPLS stack. The outermost label is the Interior Gateway protocol (IGP) label and the inner label is the VPN label. Layer 3 VPN traffic is sent from PE 1 to ASBR 1 in AS-65001 and from ASBR 2 to PE 3 in AS-65002 over a MPLS cloud. At ASBR 1, both the labels (IGP and VPN) are popped (removed). From ASBR 1 to ASBR 2 traffic flows as an unlabelled IP packet on a VRF interface. In this example, the routing protocol used between the two ASBRs is eBGP. The two label MPLS stack is pushed once the IP packet reaches ASBR 2. After the packet reaches PE 3, the VPN label is removed. The IGP label is also popped in case of explicit NULL IGP. The VPN packet is sent to CE4 through a VRF interface.

InterAS Option B

In an interAS option B network, ASBR ports are connected by one or more interfaces that are enabled to receive MPLS traffic. With this option, the ASBRs peer with each other using eBGP session. The ASBR also functions as a PE router and peers with every PE router in their AS. The ASBR does not hold any VRFs but holds all or a subset of VPNv4 routes from PE router that need to be passed to the other AS. VPNv4 routes are kept unique in ASBR using route-distinguisher and are filtered using route targets. The ASBRs exchange VPNv4 routes and VPN labels using eBGP.
Figure 2. Topology for InterAS Option B

Two methods are supported to distribute the next hop for VPNv4 routes between ASBRs. There is no requirement for LDP or any IGP to be enabled on the link connecting the two ASBRs. The MP-eBGP session between directly connected interfaces on the ASBRs enables the interfaces to forward labeled packets. To ensure this MPLS forwarding for directly connected BGP peers, you must configure mpls bgp forwarding command on the interface connecting to ASBR. This command is implemented in the IOS for directly connected interfaces. Upto 200 BGP neighbors can be configured.

  • Next-hop-self Method: Changing next-hop to that of the local ASBR for all VPNv4 routes learnt from the other ASBR.

  • Redistribute Connected Subnets Method: Redistributing the next hop address of the remote ASBR into the local IGP using redistribute connected subnets command , i.e., the next hop is not changed when the VPNv4 routes are redistributed into the local AS.


Note

In case of multiple equal paths - ECMP towards remote AS, you have to configure MPLS static label bindings towards remote Loopback on ASBR. Otherwise, you may experience packet loss.

The label switch path forwarding sections described below has AS200 configured with the Next-hop-self method and the AS300 is configured with Redistribute-subnet method.

Next-Hop Self Method

The following figure shows the label forwarding path for next-hop-self method. The labels get pushed, swapped and popped on the stack as packet makes its way from PE-200 in AS 200 to PE-300 in AS 300. In step 5, ASBR-A300 receives labeled frame, replaces label 164 with label 161 pushes IGP label 162 onto the label stack.

Redistribute Connected Subnet Method

The following figure shows the label forwarding path for Redistribute connected subnets method. The labels get pushed, swapped and popped on the stack as packet travels from PE- 300 in AS 300 to PE-200 in AS 200. In step 5, ASBR-A200 receives frame with BGP label 20, swaps it with label 29 and pushes label 17.

How to Configure MPLS VPN InterAS Options

The following section provides information about how to configure MPLS VPN InterAS Options.

Configuring MPLS VPN InterAS Option A

Sending AS: Configuring PE

Complete the following tasks to configure the PE which is in the AS sending data to another AS.

Sending AS: Configuring a VRF for a PE

Beginning in user EXEC mode complete the following steps to configure a VRF for a PE which is in the sending AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. vrf definition vrf-name
  4. rd route-distinguisher
  5. address-family ipv4
  6. route- target export route-target-ext-community
  7. route- target import route-target-ext-community
  8. exit- address- family
  9. address- family ipv6
  10. route- target export route-target-ext-community
  11. route- target import route-target-ext-community
  12. exit-address-family

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

vrf definition vrf-name

Example:

Device(config)# vrf definition cu1
Device(config-vrf)#

Configures a VRF table and enters VRF configuration mode.

Step 4

rd route-distinguisher

Example:

Device(config-vrf)# rd 1:1

Creates routing and forwarding tables for a VRF instance.

Step 5

address-family ipv4

Example:

Device(config-vrf)# address-family ipv4
Device(config-vrf-af)#

Places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv6 address prefixes.

Step 6

route- target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 100:1

Creates a list of export route target communities for the specified VRF.

Step 7

route- target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 100:2

Creates a list of import route target communities for the specified VRF.

Step 8

exit- address- family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Exits the address family configuration mode and returns to VRF configuration mode.

Step 9

address- family ipv6

Example:

Device(config-vrf)# address-family ipv6

Places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv6 address prefixes.

Step 10

route- target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 100:101

Creates a list of export route target communities for the specified VRF.

Step 11

route- target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 100:102

Creates a list of import route target communities for the specified VRF.

Step 12

exit-address-family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Exits the address family configuration mode and returns to VRF configuration mode.
Sending AS: Configuring a PE-CE Interface

Beginning in privileged EXEC mode complete the following steps to configure a PE-CE interface which is in the sending AS:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. encapsulation dot1q vlan-id
  4. vrf forwarding vrf-name
  5. ip address ip address mask [ secondary]
  6. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface Gi1/1/0/13.1
Device(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

encapsulation dot1q vlan-id

Example:

Device(config-if)# encapsulation dot1q 900

Enables IEEE 802.1Q encapsulation of traffic on a specified interface.

Step 4

vrf forwarding vrf-name

Example:

Device(config-if)# vrf forwarding cu1

Associates the VRF with the Layer 3 interface.

Step 5

ip address ip address mask [ secondary]

Example:

Device(config-if)# ip address 140.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 6

exit

Example:

Device(config-if)# exit
Device(config)#

Exits interface configuration mode and returns to global configuration mode.
Sending AS: Configuring BGP

Beginning in user EXEC mode complete the following steps to configure a BGP session for a PE which is in the sending AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router bgp autonomous-system-number
  4. neighbor ip-address remote-as as-number
  5. address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
  6. neighbor ip-address activate
  7. exit address-family
  8. address-family vpnv4
  9. neighbor ip-address activate
  10. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  11. exit address-family
  12. address-family vpnv6
  13. neighbor ip-address activate
  14. neighbor ip-address send-community extended
  15. exit address-family
  16. address-family ipv4 vrf vrf-name
  17. redistribute protocol
  18. neighbor ip-address remote-as as-number
  19. neighbor ip-address activate
  20. exit address-family
  21. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

router bgp autonomous-system-number

Example:

Device(config)# router bgp 65001
Device(config-router)#

Configures a BGP routing process.

Step 4

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 2.2.2.2 remote-as 65001

Configures an entry to the BGP neighbor table.

Step 5

address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]

Example:

Device(config-router)# address-family ipv4
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IPv4 address prefixes.

Step 6

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 2.2.2.2 activate

Enables the exchange of information with a BGP neighbor.

Step 7

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 8

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 9

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 2.2.2.2 activate

Enables the exchange of information with a BGP neighbor.

Step 10

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 2.2.2.2 send-community both

Enables the exchange of information with a BGP neighbor.

Step 11

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 12

address-family vpnv6

Example:

Device(config-router)# address-family vpnv6
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv6 address prefixes.

Step 13

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 2.2.2.2 activate

Enables the exchange of information with a BGP neighbor.

Step 14

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 2.2.2.2 send-community extended

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

Step 15

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 16

address-family ipv4 vrf vrf-name

Example:

Device(config-router)# address-family ipv4 vrf cu1
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IPv4 address prefixes.

Step 17

redistribute protocol

Example:

Device(config-router-af)# redistribute connected

Redistributes routes from one routing domain into another routing domain.

Step 18

neighbor ip-address remote-as as-number

Example:

Device(config-router-af)# neighbor 140.1.1.2 remote-as 65002

Configures an entry to the BGP neighbor table.

Step 19

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 140.1.1.2 activate

Enables the exchange of information with a BGP neighbor.

Step 20

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 21

exit

Example:

Device(config-router)# exit

Exits router BGP mode.
Sending AS: Configuring a PE-P Interface and IGP

Beginning in user EXEC mode complete the following steps to configure a PE-P interface and IGP which is in the sending AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface { interface-id| subinterface-id| vlan-id}
  4. no switchport
  5. ip address ip-address mask
  6. ip ospf process-id area area-id
  7. mpls ip
  8. exit
  9. router ospf process-id
  10. router-id ip-address
  11. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

interface { interface-id| subinterface-id| vlan-id}

Example:
Device(config)# interface po91
Device(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 4

no switchport

Example:
Device(config-if)# no switchport

Sets the interface to the routed-interface status and erases all Layer 2 configurations.

Step 5

ip address ip-address mask

Example:
Device(config-if)# ip address 91.1.1.1 255.255.255.248

Sets a primary or secondary IP address for an interface.

Step 6

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 2 area 0

Enables OSPF on an interface.

Step 7

mpls ip

Example:
Device(config-if)# mpls ip

Enables MPLS forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 8

exit

Example:
Device(config-if)# exit

Exits interface configuration mode.

Step 9

router ospf process-id

Example:

Device(config)# router ospf 2

Configures an OSPF routing process and assigns a process number.

Step 10

router-id ip-address

Example:

Device(config-router)# router-id 1.1.1.1

Specifies a fixed router ID.

Step 11

end

Example:
Device(config-router)# end

Exits router configuration mode and returns to privileged EXEC mode.

Sending AS: Configuring P

Complete the following tasks to configure the P which is in the AS sending data to another AS.

Sending AS: Configuring P-PE Interface and IGP

Beginning in user EXEC mode complete the following steps to configure a P-PE interface and IGP which is in the sending AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface { interface-id | subinterface-id | vlan-id}
  4. no switchport
  5. ip address ip-address mask
  6. ip ospf process-id area area-id
  7. mpls ip
  8. exit
  9. interface { interface-id | subinterface-id | vlan-id}
  10. no switchport
  11. ip address ip-address mask
  12. ip ospf process-id area area-id
  13. mpls ip
  14. exit
  15. router ospf process-id
  16. router-id ip-address
  17. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

interface { interface-id | subinterface-id | vlan-id}

Example:

Device(config)# interface Port-channel91
Device(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 4

no switchport

Example:
Device(config-if)# no switchport

Sets the interface to the routed-interface status and erases all Layer 2 configuration.

Step 5

ip address ip-address mask

Example:
Device(config-if)# ip address 91.1.1.2 255.255.255.248

Sets a primary or secondary IP address for an interface.

Step 6

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 2 area 0

Enables OSPF on an interface.

Step 7

mpls ip

Example:
Device(config-if)# mpls ip

Enables MPLS forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 8

exit

Example:
Device(config-if)# exit
Device(config)#

Exits interface configuration mode.

Step 9

interface { interface-id | subinterface-id | vlan-id}

Example:

Device(config)# interface Port-channel92

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 10

no switchport

Example:
Device(config-if)# no switchport

Set the interface to the routed-interface status erases all Layer 2 configurations.

Step 11

ip address ip-address mask

Example:
Device(config-if)# ip address 92.1.1.2 255.255.255.248

Sets a primary or secondary IP address for an interface.

Step 12

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 2 area 0

Enables OSPF on an interface.

Step 13

mpls ip

Example:
Device(config-if)# mpls ip

Enables MPLS forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 14

exit

Example:
Device(config-if)# exit

Exits interface configuration mode.

Step 15

router ospf process-id

Example:

Device(config)# router ospf 2
Device(config-router)#

Configures an OSPF routing process and assign a process number.

Step 16

router-id ip-address

Example:

Device(config-router)# router-id 5.5.5.5

Specifies a fixed router ID.

Step 17

end

Example:

Device(config-router)# end

Exits router configuration mode, and returns to privileged EXEC mode.

Sending AS: Configuring ASBR

Complete the following tasks to configure the ASBR which is in the AS sending data to another AS.

Sending AS: Configuring VRF for ASBR

Beginning in user EXEC mode complete the following steps to configure a VRF for a ASBR which is in the sending AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. vrf definition vrf-name
  4. rd route-distinguisher
  5. address-family ipv4
  6. route-target export route-target-ext-community
  7. route-target import route-target-ext-community
  8. exit-address-family
  9. address-family ipv6
  10. route-target export route-target-ext-community
  11. route-target importroute-target-ext-community
  12. exit-address-family
  13. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

vrf definition vrf-name

Example:

Device(config)# vrf definition cu1
Device(config-vrf)#

Configures a VRF table and enters VRF configuration mode.

Step 4

rd route-distinguisher

Example:

Device(config-vrf)# rd 1:2

Creates routing and forwarding tables for a VRF instance.

Step 5

address-family ipv4

Example:

Device(config-vrf)# address-family ipv4
Device(config-vrf-af)#

The address-family ipv4 command places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv4 address prefixes.

Step 6

route-target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 100:2

Creates a list of export route target communities for the specified VRF.

Step 7

route-target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 100:1

Creates a list of import route target communities for the specified VRF.

Step 8

exit-address-family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Leaves the address family configuration mode and returns to router configuration mode.

Step 9

address-family ipv6

Example:

Device(config-vrf)# address-family ipv6

Places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv6 address prefixes.

Step 10

route-target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 100:102

Creates a list of export route target communities for the specified VRF.

Step 11

route-target importroute-target-ext-community

Example:

Device(config-vrf-af)# route-target import 100:101

Creates a list of import route target communities for the specified VRF.

Step 12

exit-address-family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Exits the address family configuration mode and returns to router configuration mode.

Step 13

exit

Example:

Device(config-vrf)# exit

Exits the router configuration mode and returns to global configuration mode.
Sending AS: Configuring Interface Towards the Receiving ASBR

Beginning in privileged EXEC mode complete the following steps to configure an interface towards the receiving ASBR:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. encapsulation dot1q vlan-id
  4. vrf forwarding vrf-name
  5. ip address ip address mask [secondary]

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface fo1/0/10.1
Device(config-subif)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

encapsulation dot1q vlan-id

Example:

Device(config-subif)# encapsulation dot1q 900

Enables IEEE 802.1Q encapsulation of traffic on a specified interface.

Step 4

vrf forwarding vrf-name

Example:

Device(config-subif)# vrf forwarding cu1

Associates the VRF with the Layer 3 interface.

Step 5

ip address ip address mask [secondary]

Example:

Device(config-subif)# ip address 141.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Sending AS: Configuring BGP

Beginning in privileged EXEC mode complete the following steps to configure a BGP session on the ASBR which is in the sending AS:

SUMMARY STEPS

  1. configure terminal
  2. router bgp autonomous-system-number
  3. bgp log-neighbor changes
  4. neighbor ip-address remote-as as-number
  5. neighbor ip-address update-source interface-type interface-number
  6. address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
  7. neighbor ip-address activate
  8. exit-address-family
  9. address-family vpnv4
  10. neighbor ip-address activate
  11. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  12. exit-address-family
  13. address-family vpnv6
  14. neighbor ip-address activate
  15. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  16. exit-address-family
  17. address-family ipv4 vrf vrf-name
  18. redistribute protocol
  19. neighbor ip-address remote-as as-number
  20. neighbor ip-address activate
  21. exit-address-family

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

router bgp autonomous-system-number

Example:

Device(config-if)# router bgp 65001

Configures a BGP routing process.

Step 3

bgp log-neighbor changes

Example:

Device(config-router)# bgp log-neighbor-changes

Enables logging of BGP neighbor resets.

Step 4

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 1.1.1.1 remote-as 65001

Configures an entry to the BGP neighbor table.

Step 5

neighbor ip-address update-source interface-type interface-number

Example:

Device(config-router)# neighbor 1.1.1.1 update-source Loopback0

Allows Cisco IOS software to use a specific operational interface for TCP connections by the BGP sessions.

Step 6

address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]

Example:

Device(config-router)# address-family ipv4
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 7

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 1.1.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 8

exit-address-family

Example:

Device(config-router-af)# exit-address-family

Exits BGP address-family submode.

Step 9

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 10

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 1.1.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 11

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 1.1.1.1 send-community both

Enables the exchange of information with a BGP neighbor.

Step 12

exit-address-family

Example:

Device(config-router-af)# exit-address-family
Device(config-router)#

Exits BGP address-family submode.

Step 13

address-family vpnv6

Example:

Device(config-router)# address-family vpnv6
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv6 address prefixes.

Step 14

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 1.1.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 15

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 1.1.1.1 send-community both

Enables the exchange of information with a BGP neighbor.

Step 16

exit-address-family

Example:

Device(config-router-af)# exit-address-family
Device(config-router)#

Exits BGP address-family submode.

Step 17

address-family ipv4 vrf vrf-name

Example:

Device(config-router)# address-family ipv4 vrf cu1

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 18

redistribute protocol

Example:

Device(config-router-af)# redistribute connected

Redistributes routes from one routing domain into another routing domain.

Step 19

neighbor ip-address remote-as as-number

Example:

Device(config-router-af)# neighbor 141.1.1.2 remote-as 65002

Configures an entry to the BGP neighbor table.

Step 20

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 141.1.1.2 activate

Enables the exchange of information with a BGP neighbor.

Step 21

exit-address-family

Example:

Device(config-router-af)# exit-address-family

Exits BGP address-family submode.
Sending AS: Configuring a ASBR-P Interface and a IGP

Beginning in privileged EXEC mode complete the following steps to configure a ASBR-P interface and a IGP in the sending AS:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. no switchport
  4. ip address ip-address mask
  5. ip ospf process-id area area-id
  6. mpls ip
  7. end

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:
Device(config)# interface Port-channel92

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

no switchport

Example:
Device(config-if)# no switchport

Set the interface to the routed-interface status erases all Layer 2 configurations.

Step 4

ip address ip-address mask

Example:
Device(config-if)# ip address 92.1.1.1 255.255.255.248

Sets a primary or secondary IP address for an interface.

Step 5

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 2 area 0

Enables OSPF on an interface.

Step 6

mpls ip

Example:
Device(config-if)# mpls ip

Enables Multiprotocol Label Switching (MPLS) forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 7

end

Example:
Device(config-if)# end

Exits interface configuration mode and returns to privileged EXEC mode.

Receiving AS: Configuring ASBR

Complete the following tasks to configure the ASBR which is in the AS receiving data from another AS.

Receiving AS: Configuring VRF for ASBR

Beginning in user EXEC mode complete the following steps to configure a VRF for a ASBR which is in the receiving AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. vrf definition vrf-name
  4. rd route-distinguisher
  5. address-family ipv4
  6. route-target import route-target-ext-community
  7. route-target export route-target-ext-community
  8. exit-address-family
  9. address-family ipv6
  10. route-target export route-target-ext-community
  11. route-target import route-target-ext-community
  12. exit-address-family
  13. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

vrf definition vrf-name

Example:

Device(config)# vrf definition cu1
Device(config-vrf)#

Configures a VRF table and enters VRF configuration mode.

Step 4

rd route-distinguisher

Example:

Device(config-vrf)# rd 1:3

Creates routing and forwarding tables for a VRF instance.

Step 5

address-family ipv4

Example:

Device(config-vrf)# address-family ipv4
Device(config-vrf-af)#

The address-family ipv4 command places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv4 address prefixes.

Step 6

route-target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 200:2

Creates a list of export route target communities for the specified VRF.

Step 7

route-target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 200:1

Creates a list of import route target communities for the specified VRF.

Step 8

exit-address-family

Example:

Device(config-vrf-af)# exit-address-family

Leaves the address family configuration mode and returns to router configuration mode.

Step 9

address-family ipv6

Example:

Device(config-vrf)# address-family ipv6
Device(config-vrf-af)#

Places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv6 address prefixes.

Step 10

route-target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 200:101

Creates a list of export route target communities for the specified VRF.

Step 11

route-target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 200:102

Creates a list of import route target communities for the specified VRF.

Step 12

exit-address-family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Exits the address family configuration mode and returns to router configuration mode.

Step 13

exit

Example:

Device(config-vrf)# exit

Exits the router configuration mode and returns to global configuration mode.
Receiving AS: Configuring Interface Towards the Sending ASBR

Beginning in privileged EXEC mode complete the following steps to configure an interface towards the sending ASBR:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. encapsulation dot1q vlan-id
  4. vrf forwarding vrf-name
  5. ip address ip address mask [ secondary]
  6. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface fo1/0/10.1
Device(config-subif)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

encapsulation dot1q vlan-id

Example:

Device(config-subif)# encapsulation dot1q 900

Enables IEEE 802.1Q encapsulation of traffic on a specified interface.

Step 4

vrf forwarding vrf-name

Example:

Device(config-subif)# vrf forwarding cu1

Associates the VRF with the Layer 3 interface.

Step 5

ip address ip address mask [ secondary]

Example:

Device(config-subif)# ip address 141.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 6

exit

Example:

Device(config-subif)# exit
Device(config)#

Exits to global configuration mode.

Receiving AS: Configuring BGP

Beginning in privileged EXEC mode complete the following steps to configure a BGP session on the ASBR which is in the receiving AS:

SUMMARY STEPS

  1. configure terminal
  2. router bgp autonomous-system-number
  3. neighbor ip-address remote-as as-number
  4. address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
  5. neighbor ip-address activate
  6. exit
  7. address-family ipv6
  8. neighbor ip-address activate
  9. exit address-family
  10. address-family vpnv4
  11. neighbor ip-address activate
  12. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  13. exit
  14. address-family vpnv6
  15. neighbor ip-address activate
  16. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  17. exit
  18. address-family ipv4
  19. neighbor ip-address remote-as as-number
  20. neighbor ip-address activate
  21. exit address-family
  22. end

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

router bgp autonomous-system-number

Example:

Device(config)# router bgp 65002
Device(config-router)#

Configures a BGP routing process.

Step 3

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 30.30.30.30 remote-as 65002

Configures an entry to the BGP neighbor table.

Step 4

address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]

Example:

Device(config-router)# address-family ipv4
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 5

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 30.30.30.30 activate

Enables the exchange of information with a BGP neighbor.

Step 6

exit

Example:

Device(config-router-af)# exit
Device(config-router)#

Exits BGP address-family submode.

Step 7

address-family ipv6

Example:

Device(config-router)# address-family ipv6
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 8

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 30.30.30.30 activate

Enables the exchange of information with a BGP neighbor.

Step 9

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 10

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv6 address prefixes.

Step 11

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 30.30.30.30 activate

Enables the exchange of information with a BGP neighbor.

Step 12

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 30.30.30.30 send-community both

Enables the exchange of information with a BGP neighbor.

Step 13

exit

Example:

Device(config-router-af)# exit
Device(config-router)#

Exits BGP address-family submode.

Step 14

address-family vpnv6

Example:

Device(config-router)# address-family vpnv6
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 15

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 30.30.30.30 activate

Enables the exchange of information with a BGP neighbor.

Step 16

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 30.30.30.30 send-community both

Enables the exchange of information with a BGP neighbor.

Step 17

exit

Example:

Device(config-router-af)# exit
Device(config-router)#

Exits BGP address-family submode.

Step 18

address-family ipv4

Example:

Device(config-router)# address-family ipv4 vrf cu1
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 19

neighbor ip-address remote-as as-number

Example:

Device(config-router-af)# neighbor 141.1.1.1 remote-as 65001

Configures an entry to the BGP neighbor table.

Step 20

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 141.1.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 21

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 22

end

Example:

Device(config-router)# end

Exits router BGP mode and returns to privileged EXEC mode.
Receiving AS: Configuring a ASBR-P Interface and a IGP

Beginning in privileged EXEC mode complete the following steps to configure a ASBR-P interface and a IGP which is in the receiving AS:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. no switchport
  4. ip address ip-address mask
  5. ip ospf process-id area area-id
  6. mpls ip
  7. end

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface FortyGigabitEthernet1/0/13

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

no switchport

Example:

Device(config-if)# no switchport

Set the interface to the routed-interface status erases all Layer 2 configurations.

Step 4

ip address ip-address mask

Example:

Device(config-if)# ip address 10.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 5

ip ospf process-id area area-id

Example:

Device(config-if)# ip ospf 10 area 0

Enables OSPF on an interface.

Step 6

mpls ip

Example:

Device(config-if)# mpls ip

Enables Multiprotocol Label Switching (MPLS) forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 7

end

Example:

Device(config-if)# end

Exits interface configuration mode and returns to privileged EXEC mode.

Receiving AS: Configuring P

Complete the following tasks to configure the P which is in the AS receiving data from another AS.

Receiving AS: Configuring ASBR-P Interface and IGP

Beginning in user EXEC mode complete the following steps to configure a ASBR-P interface and IGP which is in the receiving AS:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. no switchport
  4. ip address ip-address mask
  5. ip ospf process-id area area-id
  6. mpls ip
  7. exit
  8. interface { interface-id| subinterface-id| vlan-id}
  9. no switchport
  10. ip address ip-address mask
  11. ip ospf process-id area area-id
  12. mpls ip
  13. exit
  14. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface HundredGigE1/0/13
Device(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

no switchport

Example:
Device(config-if)# no switchport

Set the interface to the routed-interface status erases all Layer 2 configurations.

Step 4

ip address ip-address mask

Example:
Device(config-if)# ip address 10.1.1.2 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 5

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 10 area 0

Enables OSPF on an interface.

Step 6

mpls ip

Example:
Device(config-if)# mpls ip

Enables Multiprotocol Label Switching (MPLS) forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 7

exit

Example:
Device(config-if)# exit

Exits interface configuration mode.

Step 8

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface HundredGigE1/0/4
Device(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 9

no switchport

Example:
Device(config-if)# no switchport

Set the interface to the routed-interface status and erases all Layer 2 configurations.

Step 10

ip address ip-address mask

Example:
Device(config-if)# ip address 20.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 11

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 10 area 0

Enables OSPF on an interface.

Step 12

mpls ip

Example:
Device(config-if)# mpls ip

Enables MPLS forwarding of IPv4 and IPv6 packets along normally routed paths for a particular interface.

Step 13

exit

Example:
Device(config-if)# exit
Device(config)#

Exits interface configuration mode and returns to global configuration mode.

Step 14

exit

Example:

Device(config)# exit

Exits router configuration mode, and returns to privileged EXEC mode.

Receiving AS: Configuring PE

Complete the following tasks to configure the PE which is in the AS receiving data from another AS.

Configuring VRF for PE2

Beginning in privileged EXEC mode complete the following steps to configure a VRF for a PE:

SUMMARY STEPS

  1. configure terminal
  2. vrf definition vrf-name
  3. rd route-distinguisher
  4. address- family ipv4
  5. route- target export route-target-ext-community
  6. route- target import route-target-ext-community
  7. exit- address- family
  8. address- familyipv6
  9. route- target export route-target-ext-community
  10. route- target import route-target-ext-community
  11. exit- address- family
  12. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

vrf definition vrf-name

Example:

Device(config)# vrf definition cu1
Device(config-vrf)#

Configures a VRF table and enters VRF configuration mode.

Step 3

rd route-distinguisher

Example:

Device(config-vrf)# rd 1:4

Creates routing and forwarding tables for a VRF instance.

Step 4

address- family ipv4

Example:

Device(config-vrf)# address-family ipv4
Device(config-vrf-af)#

The address-family ipv4 command places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv4 address prefixes.

Step 5

route- target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 200:2

Creates a list of export route target communities for the specified VRF.

Step 6

route- target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 200:1

Creates a list of import route target communities for the specified VRF.

Step 7

exit- address- family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Leaves the address family configuration mode and returns to router configuration mode.

Step 8

address- familyipv6

Example:

Device(config-vrf)# address-family ipv6
Device(config-vrf-af)#

Places the device in address family configuration mode, from which you can configure routing sessions that use standard IPv6 address prefixes.

Step 9

route- target export route-target-ext-community

Example:

Device(config-vrf-af)# route-target export 200:102

Creates a list of export route target communities for the specified VRF.

Step 10

route- target import route-target-ext-community

Example:

Device(config-vrf-af)# route-target import 200:101

Creates a list of import route target communities for the specified VRF.

Step 11

exit- address- family

Example:

Device(config-vrf-af)# exit-address-family
Device(config-vrf)#

Exits the address family configuration mode and returns to router configuration mode.

Step 12

exit

Example:

Device(config-vrf)# exit
Device(config)#

Exits the router configuration mode and returns to global configuration mode.
Receiving AS: Configuring PE-CE Interface

Beginning in privileged EXEC mode complete the following steps to configure a PE-CE interface which is in the receiving AS:

SUMMARY STEPS

  1. configure terminal
  2. interface { interface-id| subinterface-id| vlan-id}
  3. encapsulation dot1q vlan-id
  4. vrf forwarding vrf-name
  5. ip address ip address mask [ secondary]
  6. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

interface { interface-id| subinterface-id| vlan-id}

Example:

Device(config)# interface FortyGigabitEthernet1/0/5.1
Device(config-subif)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 3

encapsulation dot1q vlan-id

Example:

Device(config-subif)# encapsulation dot1q 900

Enables IEEE 802.1Q encapsulation of traffic on a specified interface.

Step 4

vrf forwarding vrf-name

Example:

Device(config-subif)# vrf forwarding cu1

Associates the VRF with the Layer 3 interface.

Step 5

ip address ip address mask [ secondary]

Example:

Device(config-subif)# ip address 151.1.1.1 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 6

exit

Example:

Device(config-subif)# exit
Device(config)#

Exits interface configuration mode and returns to global configuration mode.
Receiving AS: Configuring BGP

Beginning in privileged EXEC mode complete the following steps to configure a BGP session on a PE which is in the receiving AS:

SUMMARY STEPS

  1. configure terminal
  2. router bgp autonomous-system-number
  3. bgp log-neighbor changes
  4. neighbor ip-address remote-as as-number
  5. neighbor ip-address update-source interface-type interface-number
  6. address-family ipv4
  7. neighbor ip-address activate
  8. exit-address-family
  9. address-family vpnv4
  10. neighbor ip-address activate
  11. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  12. exit-address-family
  13. address-family ipv6
  14. neighbor ip-address activate
  15. exit-address-family
  16. address-family vpnv6
  17. neighbor ip-address activate
  18. neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
  19. exit address-family
  20. address-family ipv4 vrf vrf-name]
  21. redistribute protocol
  22. neighbor ip-address remote-as as-number
  23. neighbor ip-address activate
  24. exit address-family
  25. exit

DETAILED STEPS

  Command or Action Purpose

Step 1

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 2

router bgp autonomous-system-number

Example:

Device(config-if)# router bgp 65002

Configures a BGP routing process.

Step 3

bgp log-neighbor changes

Example:

Device(config-router)# bgp log-neighbor-changes

Enables logging of BGP neighbor resets.

Step 4

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 10.10.10.10 remote-as 65002

Configures an entry to the BGP neighbor table.

Step 5

neighbor ip-address update-source interface-type interface-number

Example:

Device(config-router)# neighbor 10.10.10.10 update-source Loopback30

Allows Cisco IOS software to use a specific operational interface for TCP connections by the BGP sessions.

Step 6

address-family ipv4

Example:

Device(config-router)# address-family ipv4
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 7

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.10.10.10 activate

Enables the exchange of information with a BGP neighbor.

Step 8

exit-address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 9

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4
Device(config-router-af)#

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 10

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.10.10.10 activate

Enables the exchange of information with a BGP neighbor.

Step 11

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 10.10.10.10 send-community both

Enables the exchange of information with a BGP neighbor.

Step 12

exit-address-family

Example:

Device(config-router-af)# exit-address-family
Device(config-router)#

Exits BGP address-family submode.

Step 13

address-family ipv6

Example:

Device(config-router)# address-family ipv6

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv6 address prefixes.

Step 14

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.10.10.10 activate

Enables the exchange of information with a BGP neighbor.

Step 15

exit-address-family

Example:

Device(config-router-af)# exit-address-family
Device(config-router)#

Exits BGP address-family submode.

Step 16

address-family vpnv6

Example:

Device(config-router)# address-family vpnv6

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 17

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.10.10.10 activate

Enables the exchange of information with a BGP neighbor.

Step 18

neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]

Example:

Device(config-router-af)# neighbor 10.10.10.10 send-community both

Enables the exchange of information with a BGP neighbor.

Step 19

exit address-family

Example:

Device(config-router-af)# exit address-family

Exits BGP address-family submode.

Step 20

address-family ipv4 vrf vrf-name]

Example:

Device(config-router)# address-family ipv4 vrf cu1
Device(config-router-af)#

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 21

redistribute protocol

Example:

Device(config-router-af)# redistribute connected

Redistributes routes from one routing domain into another routing domain.

Step 22

neighbor ip-address remote-as as-number

Example:

Device(config-router-af)# neighbor 151.1.1.2 remote-as 65003

Configures an entry to the BGP neighbor table.

Step 23

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 151.1.1.2 activate

Enables the exchange of information with a BGP neighbor.

Step 24

exit address-family

Example:

Device(config-router-af)# exit address-family
Device(config-router)#

Exits BGP address-family submode.

Step 25

exit

Example:

Device(config-router)# exit

Exits router configuration mode.
Receiving AS: Configuring a PE-P Interface and IGP

Beginning in user EXEC mode complete the following steps to configure a PE-P interface and IGP which is in the receiving AS:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface { interface-id| subinterface-id| vlan-id}
  4. no switchport
  5. ip address ip-address mask
  6. ip ospf process-id area area-id
  7. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

interface { interface-id| subinterface-id| vlan-id}

Example:
Device(config)# interface FortyGigabitEthernet1/0/4
(config-if)#

Enters interface configuration mode and specifies the Ethernet interface, subinterface, or VLAN to be associated with the VRF.

Step 4

no switchport

Example:
Device(config-if)# no switchport

Set the interface to the routed-interface status erases all Layer 2 configurations.

Step 5

ip address ip-address mask

Example:
Device(config-if)# ip address 20.1.1.2 255.255.255.0

Sets a primary or secondary IP address for an interface.

Step 6

ip ospf process-id area area-id

Example:
Device(config-if)# ip ospf 10 area 0

Enables OSPF on an interface.

Step 7

end

Example:
Device(config-if)# end
Device(config)#

Exits interface configuration mode and returns to privileged EXEC mode.

Configuring MPLS VPN InterAS Option B

Configuring InterAS Option B using the Next-Hop-Self Method

To configure interAS Option B on ASBRs using the next-hop-self method, complete the following steps:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router ospf process-id
  4. router-id ip-address
  5. nsr
  6. nsf
  7. redistribute bgp autonomous-system-number
  8. passive-interface interface-type interface-number
  9. network ip-address wildcard-mask aread area-id
  10. exit
  11. router bgp autonomous-system-number
  12. bgp router-id ip-address
  13. bgp log-neighbor changes
  14. no bgp default ipv4-unicast
  15. no bgp default route-target filter
  16. neighbor ip-address remote-as as-number
  17. neighbor ip-address update-source interface-type interface-number
  18. neighbor ip-address remote-as as-number
  19. address-family ipv4
  20. neighbor ip-address activate
  21. neighbor ip-address send-label
  22. exit address-family
  23. address-family vpnv4
  24. neighbor ip-address activate
  25. neighbor ip-address send-community extended
  26. neighbor ip-address next-hop-self
  27. neighbor ip-address activate
  28. neighbor ip-address send-community extended
  29. exit address-family
  30. bgp router-id ip-address
  31. bgp log-neighbor changes
  32. neighbor ip-address remote-as as-number
  33. neighbor ip-address update-source interface-type interface-number
  34. address-family vpnv4
  35. neighbor ip-address activate
  36. neighbor ip-address send-community extended
  37. exit address-family

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

router ospf process-id

Example:

Device(config)# router ospf 1

Configures an OSPF routing process and assign a process number.

Step 4

router-id ip-address

Example:

Device(config)# router-id 4.1.1.1

Specifies a fixed router ID.

Step 5

nsr

Example:

Device(config-router)# nsr

Configures OSPF non-stop routing (NSR).

Step 6

nsf

Example:

Device(config-router)# nsf

Confgures OSPF non-stop forwarding (NSF).

Step 7

redistribute bgp autonomous-system-number

Example:

Device(config-router)# redistribute bgp 200

Redistributes routes from a BGP autonomous system into and OSPF routing process.

Step 8

passive-interface interface-type interface-number

Example:

Device(config-router)# passive-interface GigabitEthernet 1/0/10
Device(config-router)# passive-interface Tunnel0

Disables Open Shortest Path First (OSPF) routing updates on an interface.

Step 9

network ip-address wildcard-mask aread area-id

Example:
Device(config-router)# network 4.1.1.0 0.0.0.0.255 area 0

Defines an interface on which OSPF runs and defines the area ID for that interface.

Step 10

exit

Example:

Device(config-router)# exit

Exits router configuration mode.

Step 11

router bgp autonomous-system-number

Example:

Device(config)# router bgp 200

Configures a BGP routing process.

Step 12

bgp router-id ip-address

Example:

Device(config-router)# bgp router-id 4.1.1.1

Configures a fixed router ID for the BGP routing process.

Step 13

bgp log-neighbor changes

Example:

Device(config-router)# bgp log-neighbor changes

Enables logging of BGP neighbor resets.

Step 14

no bgp default ipv4-unicast

Example:

Device(config-router)# no bgp default ipv4-unicast

Disables advertisement of routing information for address family IPv4.

Step 15

no bgp default route-target filter

Example:

Device(config-router)# no bgp default route-target filter

Disables automatic BGP route-target community filtering.

Step 16

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 4.1.1.3 remote-as 200

Configures an entry to the BGP neighbor table.

Step 17

neighbor ip-address update-source interface-type interface-number

Example:

Device(config-router)# neighbor 4.1.1.3 update-source Loopback0

Allows Cisco IOS software to use a specific operational interface for TCP connections by the BGP sessions.

Step 18

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 4.1.1.3 remote-as 300

Configures an entry to the BGP neighbor table.

Step 19

address-family ipv4

Example:

Device(config-router)# address-family ipv4

Enters address family configuration mode for configuring BGP routing sessions that use standard IP Version 4 address prefixes.

Step 20

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.32.1.2 activate

Enables the exchange of information with a BGP neighbor.

Step 21

neighbor ip-address send-label

Example:

Device(config-router-af)# neighbor 10.32.1.2 send-label

Sends MPLS labels with BGP routes to a neighboring BGP router.

Step 22

exit address-family

Example:

Device(config-router-af)# exit address-family

Exits BGP address-family submode.

Step 23

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 24

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 4.1.1.3 activate

Enables the exchange of information with a BGP neighbor.

Step 25

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 4.1.1.3 send-community extended

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

Step 26

neighbor ip-address next-hop-self

Example:

Device(config-router-af)# neighbor 4.1.1.3 next-hop-self

Configure a router as the next hop for a BGP-speaking neighbor. This is the command that implements the next-hop-self method.

Step 27

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.30.1.2 activate

Enables the exchange of information with a BGP neighbor.

Step 28

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 10.30.1.2 send-community extended

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

Step 29

exit address-family

Example:

Device(config-router-af)# exit address-family

Exits BGP address-family submode.

Step 30

bgp router-id ip-address

Example:

Device(config-router)# bgp router-id 4.1.1.3

Configures a fixed router ID for the BGP routing process.

Step 31

bgp log-neighbor changes

Example:

Device(config-router)# bgp log-neighbor changes

Enables logging of BGP neighbor resets.

Step 32

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 4.1.1.1 remote-as 200

Configures an entry to the BGP neighbor table.

Step 33

neighbor ip-address update-source interface-type interface-number

Example:

Device(config-router)# neighbor 4.1.1.1 update-source Loopback0

Allows Cisco IOS software to use a specific operational interface for TCP connections by the BGP sessions.

Step 34

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 35

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 4.1.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 36

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 4.1.1.1 send-community extended

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

Step 37

exit address-family

Example:

Device(config-router-af)# exit address-family

Exits BGP address-family submode.

Configuring InterAS Option B using Redistribute Connected Method

To configure interAS Option B on ASBRs using the redistribute connected method, complete the following steps:

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router ospf process-id
  4. router-id ip-address
  5. nsr
  6. nsf
  7. redistribute connected
  8. passive-interface interface-type interface-number
  9. network ip-address wildcard-mask aread area-id
  10. exit
  11. router bgp autonomous-system-number
  12. bgp router-id ip-address
  13. bgp log-neighbor changes
  14. no bgp default ipv4-unicast
  15. no bgp default route-target filter
  16. neighbor ip-address remote-as as-number
  17. neighbor ip-address update-source interface-type interface-number
  18. neighbor ip-address remote-as as-number
  19. address-family vpnv4
  20. neighbor ip-address activate
  21. neighbor ip-address send-community extended
  22. neighbor ip-address activate
  23. neighbor ip-address send-community extended
  24. exit address-family
  25. mpls ldp router-id interface-id [force]

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

router ospf process-id

Example:

Device(config)# router ospf 1

Configures an OSPF routing process and assign a process number.

Step 4

router-id ip-address

Example:

Device(config)# router-id 5.1.1.1

Specifies a fixed router ID.

Step 5

nsr

Example:

Device(config-router)# nsr

Configures OSPF non-stop routing (NSR).

Step 6

nsf

Example:

Device(config-router)# nsf

Confgures OSPF non-stop forwarding (NSF).

Step 7

redistribute connected

Example:

Device(config-router)# redistribute connected

Redistributes the next hop address of the remote ASBR into the local IGP. This is the command that implements redistribute connected method.

Step 8

passive-interface interface-type interface-number

Example:

Device(config-router)# passive-interface GigabitEthernet 1/0/10
Device(config-router)# passive-interface Tunnel0

Disables Open Shortest Path First (OSPF) routing updates on an interface.

Step 9

network ip-address wildcard-mask aread area-id

Example:
Device(config-router)# network 5.1.1.0 0.0.0.0.255 area 0

Defines an interface on which OSPF runs and defines the area ID for that interface.

Step 10

exit

Example:

Device(config-router)# exit

Exits router configuration mode.

Step 11

router bgp autonomous-system-number

Example:

Device(config)# router bgp 300

Configures a BGP routing process.

Step 12

bgp router-id ip-address

Example:

Device(config-router)# bgp router-id 5.1.1.1

Configures a fixed router ID for the BGP routing process.

Step 13

bgp log-neighbor changes

Example:

Device(config-router)# bgp log-neighbor changes

Enables logging of BGP neighbor resets.

Step 14

no bgp default ipv4-unicast

Example:

Device(config-router)# no bgp default ipv4-unicast

Disables advertisement of routing information for address family IPv4.

Step 15

no bgp default route-target filter

Example:

Device(config-router)# no bgp default route-target filter

Disables automatic BGP route-target community filtering.

Step 16

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 5.1.1.3 remote-as 300

Configures an entry to the BGP neighbor table.

Step 17

neighbor ip-address update-source interface-type interface-number

Example:

Device(config-router)# neighbor 4.1.1.3 update-source Loopback0

Allows Cisco IOS software to use a specific operational interface for TCP connections by the BGP sessions.

Step 18

neighbor ip-address remote-as as-number

Example:

Device(config-router)# neighbor 10.30.1.2 remote-as 200

Configures an entry to the BGP neighbor table.

Step 19

address-family vpnv4

Example:

Device(config-router)# address-family vpnv4

Configures the device in address family configuration mode for configuring routing sessions, such as BGP, that use standard VPNv4 address prefixes.

Step 20

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 5.1.1.3 activate

Enables the exchange of information with a BGP neighbor.

Step 21

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 5.1.1.3 send-community extended

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

Step 22

neighbor ip-address activate

Example:

Device(config-router-af)# neighbor 10.30.1.1 activate

Enables the exchange of information with a BGP neighbor.

Step 23

neighbor ip-address send-community extended

Example:

Device(config-router-af)# neighbor 10.30.1.2 send-community extended

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

Step 24

exit address-family

Example:

Device(config-router-af)# exit address-family

Exits BGP address-family submode.

Step 25

mpls ldp router-id interface-id [force]

Example:

Device(config-router)# mpls ldp router-id Loopback0 force

Specifies the preferred interface for determining the LDP router ID.

Verifying MPLS VPN InterAS Options Configuration

To verify InterAS option B configuration information, perform one of the following tasks:

Command

Purpose

ping ip-address source interface-type

Checks the accessibility of devices. Use this command to check the connection between CE1 and CE2 using the loopback interface.

show bgp vpnv4 unicast labels

Displays incoming and outgoing BGP labels.

show mpls forwarding-table

Display the contents of the MPLS Label Forwarding Information Base.

show ip bgp

Displays entries in the BGP routing table.

show { ip | ipv6 } bgp [ vrf vrf-name ]

Displays information about BGP on a VRF.

show ip route [ ip-address [ mask ]] [ protocol ] vrf vrf-name

Displays the current state of the routing table. Use the ip-address argument to verify that CE1 has a route to CE2. Verify the routes learned by CE1. Make sure that the route for CE2 is listed.

show { ip | ipv6 } route vrf vrf-name

Displays the IP routing table that is associated with a VRF. Check that the loopback addresses of the local and remote CE routers are in the routing table of the PE routers.

show running-config bgp

Displays the running configuration for BGP.

show running-config vrf vrf-name

Displays the running configuration for VRFs.

show vrf vrf-name interface interface-type interface-id

Verifies the route distinguisher (RD) and interface that are configured for the VRF.

trace destination [ vrf vrf-name ]

Discovers the routes that packets take when traveling to their destination. The trace command can help isolate a problem if two routers cannot communicate.

Configuration Examples for MPLS VPN InterAS Options

Next-Hop-Self Method

Figure 3. Topology for InterAS Option B using Next-Hop-Self Method

Configuration for PE1-P1-ASBR1

PE1

P1

ASBR1

 
vrf definition Mgmt-vrf
!
address-family ipv4
exit-address-family
!
address-family ipv6
exit-address-family
!
vrf definition vrf1
rd 200:1
route-target export 200:1
route-target import 200:1
route-target import 300:1
!
address-family ipv4
exit-address-family
interface Loopback0
ip address 4.1.1.3 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
vrf forwarding vrf1
ip address 192.1.1.1 255.255.255.255
ip ospf 200 area 0
!
interface GigabitEthernet2/0/4
no switchport
ip address 10.10.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
interface GigabitEthernet2/0/9
description to-IXIA-1:p8
no switchport
vrf forwarding vrf1
ip address 192.2.1.1 255.255.255.0
ip ospf 200 area 0
router ospf 200 vrf vrf1
router-id 192.1.1.1
nsr
nsf
redistribute connected
redistribute bgp 200
network 192.1.1.1 0.0.0.0 area 0
network 192.2.1.0 0.0.0.255 area 0
router ospf 1
router-id 4.1.1.3
nsr
nsf
redistribute connected
router bgp 200
bgp router-id 4.1.1.3
bgp log-neighbor-changes
neighbor 4.1.1.1 remote-as 200
neighbor 4.1.1.1 update-source Loopback0
!
address-family vpnv4
neighbor 4.1.1.1 activate
neighbor 4.1.1.1 send-community extended
exit-address-family
!
address-family ipv4 vrf vrf1
redistribute connected
redistribute ospf 200
maximum-paths ibgp 2
exit-address-family
 
interface Loopback0
ip address 4.1.1.2 255.255.255.255
ip ospf 1 area 0
interface GigabitEthernet1/0/4
no switchport
ip address 10.10.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
!
interface GigabitEthernet1/0/23
no switchport
ip address 10.20.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
 
interface Loopback0
ip address 4.1.1.1 255.255.255.255
ip ospf 1 area 0
interface GigabitEthernet1/0/10
no switchport
ip address 10.30.1.1 255.255.255.0
mpls bgp forwarding
interface GigabitEthernet1/0/23
no switchport
ip address 10.20.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
router ospf 1
router-id 4.1.1.1
nsr
nsf
redistribute bgp 200
passive-interface GigabitEthernet1/0/10
passive-interface Tunnel0
network 4.1.1.0 0.0.0.255 area 0
router bgp 200
bgp router-id 4.1.1.1
bgp log-neighbor-changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor 4.1.1.3 remote-as 200
neighbor 4.1.1.3 update-source Loopback0
neighbor 10.30.1.2 remote-as 300
!
address-family ipv4
neighbor 10.30.1.2 activate
neighbor 10.30.1.2 send-label
exit-address-family
!
address-family vpnv4
neighbor 4.1.1.3 activate
neighbor 4.1.1.3 send-community extended
neighbor 4.1.1.3 next-hop-self
neighbor 10.30.1.2 activate
neighbor 10.30.1.2 send-community extended
exit-address-family

Configuration for ASBR2 – P2 – PE2

Table 1.

PE2

P2

ASBR2

 
vrf definition vrf1
rd 300:1
route-target export 300:1
route-target import 300:1
route-target import 200:1
!
address-family ipv4
exit-address-family
interface Loopback0
ip address 5.1.1.3 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
vrf forwarding vrf1
ip address 193.1.1.1 255.255.255.255
ip ospf 300 area 0
interface GigabitEthernet1/0/1
no switchport
ip address 10.50.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
!
interface GigabitEthernet1/0/2
no switchport
vrf forwarding vrf1
ip address 193.2.1.1 255.255.255.0
ip ospf 300 area 0
router ospf 300 vrf vrf1
router-id 193.1.1.1
nsr
nsf
redistribute connected
redistribute bgp 300
network 193.1.1.1 0.0.0.0 area 0
network 193.2.1.0 0.0.0.255 area 0
!
router ospf 1
router-id 5.1.1.3
nsr
nsf
redistribute connected
router bgp 300
bgp router-id 5.1.1.3
bgp log-neighbor-changes
neighbor 5.1.1.1 remote-as 300
neighbor 5.1.1.1 update-source Loopback0
!
address-family ipv4
neighbor 5.1.1.1 activate
neighbor 5.1.1.1 send-label
exit-address-family
!
address-family vpnv4
neighbor 5.1.1.1 activate
neighbor 5.1.1.1 send-community extended
exit-address-family
!
address-family ipv4 vrf vrf1
redistribute connected
redistribute ospf 300
maximum-paths ibgp 2
exit-address-family
 
interface Loopback0
ip address 5.1.1.2 255.255.255.255
ip ospf 1 area 0
interface GigabitEthernet1/0/1
no switchport
ip address 10.50.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
interface GigabitEthernet2/0/3
no switchport
ip address 10.40.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
 
interface Loopback0
ip address 5.1.1.1 255.255.255.255
ip ospf 1 area 0
!
interface GigabitEthernet1/0/37
no switchport
ip address 10.30.1.2 255.255.255.0
mpls bgp forwarding
interface GigabitEthernet1/0/47
no switchport
ip address 10.40.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
router ospf 1
router-id 5.1.1.1
nsr
nsf
passive-interface GigabitEthernet1/0/37
passive-interface Tunnel0
network 5.1.1.0 0.0.0.255 area 0
!
router bgp 300
bgp router-id 5.1.1.1
bgp log-neighbor-changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor 5.1.1.3 remote-as 300
neighbor 5.1.1.3 update-source Loopback0
neighbor 10.30.1.1 remote-as 200
!
address-family ipv4
neighbor 10.30.1.1 activate
neighbor 10.30.1.1 send-label
exit-address-family
!
address-family vpnv4
neighbor 5.1.1.3 activate
neighbor 5.1.1.3 send-community extended
neighbor 5.1.1.3 next-hop-self
neighbor 10.30.1.1 activate
neighbor 10.30.1.1 send-community extended
exit-address-family

IGP Redistribute Connected Subnets Method

Figure 4. Topology for InterAS Option B using Redistribute Connected Subnets Method

Configuration for PE1-P1-ASBR1

PE1

P1

ASBR1

 
vrf definition Mgmt-vrf
!
address-family ipv4
exit-address-family
!
address-family ipv6
exit-address-family
!
vrf definition vrf1
rd 200:1
route-target export 200:1
route-target import 200:1
route-target import 300:1
!
address-family ipv4
exit-address-family
interface Loopback0
ip address 4.1.1.3 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
vrf forwarding vrf1
ip address 192.1.1.1 255.255.255.255
ip ospf 200 area 0
!
interface GigabitEthernet2/0/4
no switchport
ip address 10.10.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
interface GigabitEthernet2/0/9
description to-IXIA-1:p8
no switchport
vrf forwarding vrf1
ip address 192.2.1.1 255.255.255.0
ip ospf 200 area 0
router ospf 200 vrf vrf1
router-id 192.1.1.1
nsr
nsf
redistribute connected
redistribute bgp 200
network 192.1.1.1 0.0.0.0 area 0
network 192.2.1.0 0.0.0.255 area 0
router ospf 1
router-id 4.1.1.3
nsr
nsf
redistribute connected
router bgp 200
bgp router-id 4.1.1.3
bgp log-neighbor-changes
neighbor 4.1.1.1 remote-as 200
neighbor 4.1.1.1 update-source
Loopback0
!
address-family vpnv4
neighbor 4.1.1.1 activate
neighbor 4.1.1.1 send-community extended
exit-address-family
!
address-family ipv4 vrf vrf1
redistribute connected
redistribute ospf 200
maximum-paths ibgp 2
exit-address-family
 
interface Loopback0
ip address 4.1.1.2 255.255.255.255
ip ospf 1 area 0
interface GigabitEthernet1/0/4
no switchport
ip address 10.10.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
!
interface GigabitEthernet1/0/23
no switchport
ip address 10.20.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
 
router ospf 1
router-id 4.1.1.1
nsr
nsf
redistribute connected
passive-interface GigabitEthernet1/0/10
passive-interface Tunnel0
network 4.1.1.0 0.0.0.255 area 0
router bgp 200
bgp router-id 4.1.1.1
bgp log-neighbor-changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor 4.1.1.3 remote-as 200
neighbor 4.1.1.3 update-source
Loopback0
neighbor 10.30.1.2 remote-as 300
!
address-family vpnv4
neighbor 4.1.1.3 activate
neighbor 4.1.1.3 send-community extended
neighbor 10.30.1.2 activate
neighbor 10.30.1.2 send-community extended
exit-address-family
mpls ldp router-id Loopback0 force

Configuration for ASBR2 – P2 – PE2

PE2

P2

ASBR2

 
vrf definition vrf1
rd 300:1
route-target export 300:1
route-target import 300:1
route-target import 200:1
!
address-family ipv4
exit-address-family
interface Loopback0
ip address 5.1.1.3 255.255.255.255
ip ospf 1 area 0
!
interface Loopback1
vrf forwarding vrf1
ip address 193.1.1.1 255.255.255.255
ip ospf 300 area 0
interface GigabitEthernet1/0/1
no switchport
ip address 10.50.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
!
interface GigabitEthernet1/0/2
no switchport
vrf forwarding vrf1
ip address 193.2.1.1 255.255.255.0
ip ospf 300 area 0
router ospf 300 vrf vrf1
router-id 193.1.1.1
nsr
nsf
redistribute connected
redistribute bgp 300
network 193.1.1.1 0.0.0.0 area 0
network 193.2.1.0 0.0.0.255 area 0
!
router ospf 1
router-id 5.1.1.3
nsr
nsf
redistribute connected
router bgp 300
bgp router-id 5.1.1.3
bgp log-neighbor-changes
neighbor 5.1.1.1 remote-as 300
neighbor 5.1.1.1 update-source
Loopback0
!
address-family ipv4
neighbor 5.1.1.1 activate
neighbor 5.1.1.1 send-label
exit-address-family
!
address-family vpnv4
neighbor 5.1.1.1 activate
neighbor 5.1.1.1 send-community extended
exit-address-family
!
address-family ipv4 vrf vrf1
redistribute connected
redistribute ospf 300
maximum-paths ibgp 2
exit-address-family
 
interface Loopback0
ip address 5.1.1.2 255.255.255.255
ip ospf 1 area 0
interface GigabitEthernet1/0/1
no switchport
ip address 10.50.1.1 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
interface GigabitEthernet2/0/3
no switchport
ip address 10.40.1.2 255.255.255.0
ip ospf 1 area 0
mpls ip
mpls label protocol ldp
 
router ospf 1
router-id 5.1.1.1
nsr
nsf
redistribute connected
passive-interface GigabitEthernet1/0/10
passive-interface Tunnel0
network 5.1.1.0 0.0.0.255 area 0
router bgp 300
bgp router-id 5.1.1.1
bgp log-neighbor-changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor 5.1.1.3 remote-as 300
neighbor 5.1.1.3 update-source
Loopback0
neighbor 10.30.1.1 remote-as 200
!
address-family vpnv4
neighbor 5.1.1.3 activate
neighbor 5.1.1.3 send-community extended
neighbor 10.30.1.1 activate
neighbor 10.30.1.1 send-community extended
exit-address-family
mpls ldp router-id Loopback0 force

Additional References for MPLS VPN InterAS Options

Related Documents

Related Topic Document Title

For complete syntax and usage information for the commands used in this chapter.

See the MPLS Commands section of theCommand Reference (Catalyst 9400 Series Switches)

Feature History for MPLS VPN InterAS Options

This table provides release and related information for features explained in this module.

These features are available on all releases subsequent to the one they were introduced in, unless noted otherwise.

.

Release

Feature

Feature Information
Cisco IOS XE Gibraltar 16.11.1

MPLS VPN InterAS Option B

InterAS Options use iBGP and eBGP peering to allow VPNs in different AS to communicate with each other. In an interAS option B network, ASBR ports are connected by one or more interfaces that are enabled to receive MPLS traffic.

Cisco IOS XE Amsterdam 17.1.1

MPLS VPN InterAS Option A

MPLS VPN InterAS Option A is the simplest to configure of the available InterAS Options. This option provides back to back virtual routing and forwarding (VRF) connectivity. Here, MPLS VPN providers exchange routes across VRF interfaces.

Use Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn.