Mpls L3Vpn Restrictions - Cisco CRS Configuration Manual

Implementing MPLS Layer 3 VPNs
• To configure MPLS Layer 3 VPNs, routers must support MPLS forwarding and Forwarding Information
The following prerequisites are required for configuring MPLS VPN Inter-AS with autonomous system
boundary routers (ASBRs) exchanging VPN-IPV4 addresses or IPv4 routes and MPLS labels:
• Before configuring external Border Gateway Protocol (eBGP) routing between autonomous systems or
• These following tasks must be performed:

MPLS L3VPN Restrictions

The following are restrictions for implementing MPLS Layer 3 VPNs:
• Multihop VPN-IPv4 eBGP is not supported for configuring eBGP routing between autonomous systems
• MPLS VPN supports only IPv4 address families.
The following restrictions apply when configuring MPLS VPN Inter-AS with ASBRs exchanging IPv4 routes
and MPLS labels:
• For networks configured with eBGP multihop, a label switched path (LSP) must be configured between
• Inter-AS supports IPv4 routes only. IPv6 is not supported.
The physical interfaces that connect the BGP speakers must support FIB and MPLS.
Note
The following restrictions apply to routing protocols OSPF and RIP:
• IPv6 is not supported on OSPF and RIP.
◦ MPLS commands (generally)
◦ MPLS Layer 3 VPN commands
Base (FIB).
subautonomous systems in an MPLS VPN, ensure that all MPLS VPN routing instances and sessions
are properly configured (see the
◦ Define VPN routing instances
◦ Configure BGP routing sessions in the MPLS core
◦ Configure PE-to-PE routing sessions in the MPLS core
◦ Configure BGP PE-to-CE routing sessions
◦ Configure a VPN-IPv4 eBGP session between directly connected ASBRs
or subautonomous systems in an MPLS VPN.
non adjacent routers.
Cisco IOS XR Virtual Private Network Configuration Guide for the Cisco CRS Router, Release 6.1.x
How to Implement MPLS Layer 3

MPLS L3VPN Restrictions

VPNs, for procedures)
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