Configuring MPLS VPN InterAS Options
Information About MPLS VPN InterAS Options
- ASes and ASBRs
- MPLS VPN InterAS Options
  - InterAS Option A
  - InterAS Option B
    - Next-Hop Self Method
    - Redistribute Connected Subnet Method
How to Configure MPLS VPN InterAS Options
- Configuring MPLS VPN InterAS Option A
- Configuring MPLS VPN InterAS Option B
  - Configuring InterAS Option B using the Next-Hop-Self Method
  - Configuring InterAS Option B using Redistribute Connected Method
Verifying MPLS VPN InterAS Options Configuration
Configuration Examples for MPLS VPN InterAS Options
- Next-Hop-Self Method
- IGP Redistribute Connected Subnets Method
Additional References for MPLS VPN InterAS Options
Feature History for MPLS VPN InterAS Options

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.

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

enable
configure terminal
vrf definition vrf-name
rd route-distinguisher
address-family ipv4
route- target export route-target-ext-community
route- target import route-target-ext-community
exit- address- family
address- family ipv6
route- target export route-target-ext-community
route- target import route-target-ext-community
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
encapsulation dot1q vlan-id
vrf forwarding vrf-name
ip address ip address mask [ secondary]
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

enable
configure terminal
router bgp autonomous-system-number
neighbor ip-address remote-as as-number
address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
neighbor ip-address activate
exit address-family
address-family vpnv4
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit address-family
address-family vpnv6
neighbor ip-address activate
neighbor ip-address send-community extended
exit address-family
address-family ipv4 vrf vrf-name
redistribute protocol
neighbor ip-address remote-as as-number
neighbor ip-address activate
exit address-family
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

enable
configure terminal
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
exit
router ospf process-id
router-id ip-address
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

enable
configure terminal
interface { interface-id | subinterface-id | vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
exit
interface { interface-id | subinterface-id | vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
exit
router ospf process-id
router-id ip-address
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

enable
configure terminal
vrf definition vrf-name
rd route-distinguisher
address-family ipv4
route-target export route-target-ext-community
route-target import route-target-ext-community
exit-address-family
address-family ipv6
route-target export route-target-ext-community
route-target importroute-target-ext-community
exit-address-family
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 import`route-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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
encapsulation dot1q vlan-id
vrf forwarding vrf-name
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

configure terminal
router bgp autonomous-system-number
bgp log-neighbor changes
neighbor ip-address remote-as as-number
neighbor ip-address update-source interface-type interface-number
address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
neighbor ip-address activate
exit-address-family
address-family vpnv4
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit-address-family
address-family vpnv6
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit-address-family
address-family ipv4 vrf vrf-name
redistribute protocol
neighbor ip-address remote-as as-number
neighbor ip-address activate
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
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

enable
configure terminal
vrf definition vrf-name
rd route-distinguisher
address-family ipv4
route-target import route-target-ext-community
route-target export route-target-ext-community
exit-address-family
address-family ipv6
route-target export route-target-ext-community
route-target import route-target-ext-community
exit-address-family
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
encapsulation dot1q vlan-id
vrf forwarding vrf-name
ip address ip address mask [ secondary]
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

configure terminal
router bgp autonomous-system-number
neighbor ip-address remote-as as-number
address-family ipv4 [ mdt| multicast| tunnel| unicast [ vrf vrf-name] | [ vrf vrf-name]
neighbor ip-address activate
exit
address-family ipv6
neighbor ip-address activate
exit address-family
address-family vpnv4
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit
address-family vpnv6
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit
address-family ipv4
neighbor ip-address remote-as as-number
neighbor ip-address activate
exit address-family
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
exit
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
mpls ip
exit
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

configure terminal
vrf definition vrf-name
rd route-distinguisher
address- family ipv4
route- target export route-target-ext-community
route- target import route-target-ext-community
exit- address- family
address- familyipv6
route- target export route-target-ext-community
route- target import route-target-ext-community
exit- address- family
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

configure terminal
interface { interface-id| subinterface-id| vlan-id}
encapsulation dot1q vlan-id
vrf forwarding vrf-name
ip address ip address mask [ secondary]
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

configure terminal
router bgp autonomous-system-number
bgp log-neighbor changes
neighbor ip-address remote-as as-number
neighbor ip-address update-source interface-type interface-number
address-family ipv4
neighbor ip-address activate
exit-address-family
address-family vpnv4
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit-address-family
address-family ipv6
neighbor ip-address activate
exit-address-family
address-family vpnv6
neighbor ip-address activate
neighbor { ip-address| ipv6-address| peer-group-name} send- community [ both| standard| extended]
exit address-family
address-family ipv4 vrf vrf-name]
redistribute protocol
neighbor ip-address remote-as as-number
neighbor ip-address activate
exit address-family
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

enable
configure terminal
interface { interface-id| subinterface-id| vlan-id}
no switchport
ip address ip-address mask
ip ospf process-id area area-id
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

enable
configure terminal
router ospf process-id
router-id ip-address
nsr
nsf
redistribute bgp autonomous-system-number
passive-interface interface-type interface-number
network ip-address wildcard-mask aread area-id
exit
router bgp autonomous-system-number
bgp router-id ip-address
bgp log-neighbor changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor ip-address remote-as as-number
neighbor ip-address update-source interface-type interface-number
neighbor ip-address remote-as as-number
address-family ipv4
neighbor ip-address activate
neighbor ip-address send-label
exit address-family
address-family vpnv4
neighbor ip-address activate
neighbor ip-address send-community extended
neighbor ip-address next-hop-self
neighbor ip-address activate
neighbor ip-address send-community extended
exit address-family
bgp router-id ip-address
bgp log-neighbor changes
neighbor ip-address remote-as as-number
neighbor ip-address update-source interface-type interface-number
address-family vpnv4
neighbor ip-address activate
neighbor ip-address send-community extended
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

enable
configure terminal
router ospf process-id
router-id ip-address
nsr
nsf
redistribute connected
passive-interface interface-type interface-number
network ip-address wildcard-mask aread area-id
exit
router bgp autonomous-system-number
bgp router-id ip-address
bgp log-neighbor changes
no bgp default ipv4-unicast
no bgp default route-target filter
neighbor ip-address remote-as as-number
neighbor ip-address update-source interface-type interface-number
neighbor ip-address remote-as as-number
address-family vpnv4
neighbor ip-address activate
neighbor ip-address send-community extended
neighbor ip-address activate
neighbor ip-address send-community extended
exit address-family
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

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

PE1

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

PE2

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

PE1

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

PE2

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 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.

Multiprotocol Label Switching (MPLS) Configuration Guide, Cisco IOS XE Amsterdam 17.1.x (Catalyst 9600 Switches)

Bias-Free Language

Results

Chapter: Configuring MPLS VPN InterAS Options

Configuring MPLS VPN InterAS Options

Information About MPLS VPN InterAS Options

ASes and ASBRs

MPLS VPN InterAS Options

InterAS Option A

InterAS Option B

Next-Hop Self Method

Redistribute Connected Subnet Method

How to Configure MPLS VPN InterAS Options

Configuring MPLS VPN InterAS Option A

Sending AS: Configuring PE

Sending AS: Configuring a VRF for a PE

SUMMARY STEPS

DETAILED STEPS

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Sending AS: Configuring a PE-CE Interface

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Sending AS: Configuring BGP

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Sending AS: Configuring a PE-P Interface and IGP

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Sending AS: Configuring P

Sending AS: Configuring P-PE Interface and IGP

SUMMARY STEPS