Comprehensive and Detailed Explanation:
Inter-AS MPLS L3VPN solutions enable communication between differentAutonomous Systems (AS)while maintaining VPN separation. The three primary solutions for inter-AS MPLS L3VPN are:
Option A (Back-to-Back VRF)
MPLS isnot requiredbetween ASBRs.
VPN routes are exchangedwithout label switching.
Each ASBR has aVRF instanceconfigured and forwards traffic usingplain IP routing.
Option B (eBGP Redistribution of Labeled VPNv4 Routes)
MPLSis not requiredbetween ASBRs.
ASBRsexchange labeled VPNv4 routes using eBGP.
The ASBR doesnot perform label switchingbut simply forwards packets based on VPNv4 labels.
Option C (Multi-Hop MP-BGP for VPNv4 Routes)
MPLS is requiredbetween ASBRs.
ASBRs establishlabel-switched paths (LSPs)to forward VPN traffic across AS boundaries.
SinceOption Brelies onlabeled VPNv4 routes via eBGPand does not need MPLS between ASBRs, the correct answer isD.
????Reference:Huawei HCIE Datacom Study Guide - MPLS VPN Inter-AS Solutions
Submit