Cisco CRS Configuration Manual page 240

Providing VPN Connectivity Across Multiple Autonomous Systems with MPLS VPN Inter-AS with ASBRs Exchanging
IPv4 Routes and MPLS Labels
Example:
RP/0/RP0/CPU0:router(config-bgp-af)# allocate-label all
Allocates the MPLS labels for a specific IPv4 unicast or VPN routing and forwarding (VRF) IPv4 unicast routes so that
the BGP router can send labels with BGP routes to a neighboring router that is configured for a labeled-unicast session.
Step 5 neighbor ip-address
Example:
RP/0/RP0/CPU0:router(config-bgp-af)# neighbor 172.168.40.24
RP/0/RP0/CPU0:router(config-bgp-nbr)#
Places the router in neighbor configuration mode for BGP routing and configures the neighbor IP address 172.168.40.24
as an ASBR eBGP peer.
Step 6 remote-as autonomous-system-number
Example:
RP/0/RP0/CPU0:router(config-bgp-nbr)# remote-as 2002
Creates a neighbor and assigns it a remote autonomous system number.
Step 7
update-source type interface-path-id
Example:
RP/0/RP0/CPU0:router(config-bgp-nbr)# update-source loopback0
Allows BGP sessions to use the primary IP address from a particular interface as the local address.
Step 8
address-family ipv4 labeled-unicast
Example:
RP/0/RP0/CPU0:router(config-bgp-nbr)# address-family ipv4 labeled-unicast
RP/0/RP0/CPU0:router(config-bgp-nbr-af)#
Enters neighbor address family configuration mode for the IPv4 labeled-unicast address family.
Step 9 route-reflector-client
Example:
RP/0/RP0/CPU0:router(config-bgp-nbr-af)# route-reflector-client
Configures the router as a BGP route reflector and neighbor 172.168.40.24 as its client.
Step 10
neighbor ip-address
Example:
RP/0/RP0/CPU0:router(config-bgp-nbr-af)# neighbor 10.40.25.2
RP/0/RP0/CPU0:router(config-bgp-nbr)#
Cisco IOS XR Virtual Private Network Configuration Guide for the Cisco CRS Router, Release 6.1.x
226
Implementing MPLS Layer 3 VPNs