INTEGRATOR · MPLS L3VPN

MPLS L3VPN between a Cisco PE and a Huawei PE

The provider core already runs IS-IS and LDP. Connect customer A’s two sites through it: create the VRF on both PEs, attach the CE links, carry the customer routes in MP-BGP VPNv4 between the PE loopbacks, and prove the P router never sees a customer route. PE1 runs Cisco IOS and PE2 runs Huawei VRP: the RD and route targets must still match.

Integrator track · Cisco + Huawei · 7 objectives

Open in simulator More Integrator labs

Objectives

The simulator ticks each one as soon as the network meets it.

On PE1 and PE2, create VRF / VPN instance CUST-A with RD 65000:1 and route target 65000:1 for import and export.
Bind the CE-facing interface (G0/0, GE0/0/0 on Huawei) to CUST-A, then address it: PE1 172.16.1.1/30, PE2 172.16.2.1/30.
Add VRF static routes to the customer LANs: on PE1 192.168.1.0/24 via 172.16.1.2, on PE2 192.168.2.0/24 via 172.16.2.2.
Peer PE1 (1.1.1.1) and PE2 (3.3.3.3) in iBGP AS 65000 between loopbacks, and enable the VPNv4 address family for the peer.
Put the CUST-A connected and static routes into BGP (redistribute / import-route).
Check PE1’s CUST-A table: 192.168.2.0/24 via 3.3.3.3. Check P: no 192.168.x.x routes at all.
CE1 pings 192.168.2.1.

Start this lab

Before you start

An RD only makes the customer’s prefixes unique inside VPNv4. Route targets decide which VRFs import them. Binding an interface to a VRF removes its IP address, so bind first and address second. The P router only switches labels: it needs IS-IS and LDP, not BGP. Huawei needs route-distinguisher in ipv4-family before vpn-target, and installs a VPN route only when an LSP to its next hop exists.

Concept

BGP/MPLS Layer 3 VPN

An L3VPN carries each customer’s routes in its own routing table (VRF / VPN instance) on the provider edge, and moves their packets across a shared core with two MPLS labels. The core routers see only labels, never customer addresses.

Concept

MPLS labels and LDP

MPLS forwards packets by a short label instead of looking up the IP address at every hop. LDP gives each IGP prefix a label on every router and shares it with neighbors, building a label-switched path (LSP) through the core.