Labs MPLS

MPLS Lab Overview (Juniper ACX1100 with Logical Systems)

A lab environment designed to test MPLS functionality, logical systems isolation, VLAN-based customer separation, and traffic engineering using multiple core paths.

Note: Most of the provided labs are automated using Ansible. However, for educational purposes, we will provide only Junos configuration examples.

MPLS Lab Diagram


Components

  • ACX1100: Physical Juniper router hosting all logical systems (LS).
  • LP01, LP02, LP03: Core MPLS logical systems forming a ring topology (Core).
  • LPE01, LPE02: Provider Edge (PE) logical systems connecting to CE devices via VLANs.
  • CE Devices (ROS): 4 virtual machines acting as customer edge routers (connected via VLAN subinterfaces).

Connectivity

  • Interface ge-0/0/4: Trunk port connecting ACX1100 to a virtual environment (ROS VMs), carrying:
    • VLAN 101 → acx-ce101 (Customer A)
    • VLAN 102 → acx-ce102 (Customer A)
    • VLAN 201 → acx-ce201 (Customer B)
    • VLAN 202 → acx-ce202 (Customer B)
  • VLAN subinterfaces are mapped to specific logical systems (lpe01, lpe02) based on customer.

  • Core connectivity:
    • lpe01lp01
    • lpe02lp02
    • lp01, lp02, lp03 form an MPLS ring.

Traffic Engineering Paths

  • 🔴 Red path: LP01 → LP02
  • 🔵 Blue path: LP01 → LP03 → LP02

Used for demonstrating MPLS TE or LSP failover/optimization.


Use Case Highlights

  • L3VPN or L2VPN customer separation
  • Redundant TE path testing
  • VLAN-to-LS mapping demonstration
  • CE-to-CE communication across PE routers

Juniper ACX1100 – MPLS Feature Overview

The Juniper ACX1100 supports advanced MPLS features, allowing service providers to extend MPLS-based services closer to the customer edge.

Supported MPLS Features

Feature Description
MPLS Forwarding Hardware-based, line-rate MPLS label switching
LDP (Label Distribution Protocol) Dynamically distributes MPLS labels over IGP (OSPF/IS-IS)
RSVP-TE Traffic-engineered LSPs with bandwidth reservation and constraints
Static LSPs Manually configured LSPs for simple MPLS forwarding
BGP/MPLS L3VPN Full support for RFC 4364-based Layer 3 VPN services
BGP-based L2VPN (RFC 6624) Limited support for point-to-point Ethernet VPNs using BGP signaling
PWE (T-LDP) Pseudowire Emulation over targeted LDP for Ethernet over MPLS (E-Line)

MPLS Limitations

Unsupported Feature Notes
VPLS (LDP or BGP autodiscovery) Not supported – lacks MAC learning and control plane functions required for multipoint Ethernet VPNs
EVPN (Ethernet VPN) Not supported – no VXLAN or EVPN bridging capabilities
Komplla L2VPN Not supported – only basic BGP-signaled E-Line L2VPNs are available
MAC Learning over Pseudowires Not supported – limits use to E-Line type services only

Notes

  • While some older documentation suggests no L2VPN support, the official datasheet confirms BGP-based L2VPN and T-LDP pseudowire support.
  • Ensure you’re running a supported Junos OS version (typically 14.x or later) to access all MPLS capabilities.
  • Not suitable for full VPLS or EVPN-based service designs – consider ACX4000 or MX Series for those roles.