IGNA Online logo

IGNA Online

Archives
Log in
Subscribe
June 29, 2026

MPLS L3VPN on Cisco IOS-XE: Building and Verifying Multi-Site VPNs from Scratch

New post on ignaonline.com — this one digs deep into MPLS Layer 3 VPNs on Cisco IOS-XE.

If you've ever managed a service provider network or enterprise WAN and needed to understand how customer traffic stays isolated across a shared MPLS core, this guide walks through the full build from scratch — VRF config, LDP adjacencies, MP-BGP VPNv4 peering between PEs, and eBGP PE-CE routing — with real CLI output and show command verification at every step.

Topics covered:

  • P / PE / CE roles and the VRF/RD/RT model
  • OSPF in the provider core + LDP setup
  • MP-BGP VPNv4 address family and the send-community both gotcha
  • PE-CE eBGP with as-override
  • End-to-end verification with show bgp vpnv4 unicast all
  • Systematic troubleshooting by layer
  • Route Reflectors and Inter-AS scaling

Read the full guide →

— Sarah Chen, ignaonline.com

Don't miss what's next. Subscribe to IGNA Online:
← Newer Cisco IOS-XE IP SLA and Object Tracking: Automated Dual-ISP Failover Older → Zero-Knowledge Proofs in 2026: How zk-SNARKs and zk-STARKs Are Reshaping Blockchain Privacy and Scalability
Powered by Buttondown, the easiest way to start and grow your newsletter.