The Cisco IOS XR address-family ipv4 labeled-unicast and the Cisco IOS/IOS XE neighbor sendlabel commands are used in which MPLS implementation?
A.
Cisco MPLS TE
B.
CSC using MP-BGP for label exchange
C.
back-to-back VRF
D.
AToM
E.
VPLS
Explanation:
http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/fscscleb.pdf
The MPLS VPN—Carrier Supporting Carrier—IPv4 BGP Label Distribution feature lets you
configureyour carrier-supporting-carrier network to enable Border Gateway Protocol (BGP) to
transport routesand Multiprotocol Label Switching (MPLS) labels between the backbone carrier
provider edge (PE)routers and the customer carrier customer edge (CE) routers using multiple
paths. Previously, you hadto use Label Distribution Protocol (LDP) to carry the labels and an
Internal Gateway Protocol (IGP) tocarry the routes between PE and CE routers to achieve the
same goal.
The benefits of using BGP to distribute IPv4 routes and MPLS label routes are:
• BGP takes the place of an IGP and LDP in a Virtual Private Network (VPN)
forwarding/routinginstance (VRF) table. You can use BGP to distribute routes and MPLS labels.
Using a singleprotocol instead of two simplifies the configuration and troubleshooting.
• BGP is the preferred routing protocol for connecting two Internet service providers (ISPs),
mainlybecause of its routing policies and ability to scale. ISPs commonly use BGP between two
providers.This feature enables those ISPs to use BGP.