Blog Viewer

FAQ: VPLS on MX Series Routers

By Erdem posted 02-04-2016 11:36


MPLS technology is evolving, with more services being offered using MPLS connectivity. Junos OS features are also evolving to implement these services on Juniper Networks routers.


The most common MPLS connectivity services include:

  • Virtual Private LAN Service (VPLS)
  • Layer 3 virtual private networks (VPNs)
  • Layer 2 circuits and Layer 2 VPNs

VPLS provides a multipoint Ethernet service that emulates an Ethernet LAN. From the customer edge (CE) perspective, the service provider VPLS network operates like a private Ethernet broadcast domain.


A VPLS domain consists of a set of provider edge (PE) routers that acts as a single virtual Ethernet bridge for sites connected to those PE routers on the customer side. Pseudowire tunnels are created between those PE routers to aggregate traffic from one PE router to another. The PE routers exchange the MPLS labels used for the VPLS pseudowire, using either Label Distribution Protocol (LDP) forwarding equivalence classes (FECs), as described in RFC 4762, Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling, or BGP, as described in RFC 4761, Virtual Private LAN Service (VPLS) Using BGP for Auto-Discovery and Signaling.


Junos OS Release 11.2 and later supports BGP autodiscovery for LDP VPLS using forwarding equivalence class (FEC) 129. As a workaround for older releases, you can manually provision each LDP PE router in an LDP mesh group by including the neighbor statement.


IGMP snooping is not supported on NG-VPLS when point-to-multipoint is in the core.


To ramp up on VPLS in Junos OS, click Layer 2 VPNs and VPLS Feature Guide.


This article provides answers to the most common questions about VPLS configurations on Juniper Networks MX Series routers.


  1. What are the Juniper Networks solutions for Metro Ethernet Forum (MEF) 6.1 Ethernet services definitions?
  2. How can I prevent the receipt of hub routes on a directly-connected customer premises equipment spoke interface in a hub provider edge router?
  3. How does qualified learning for virtual private LAN service operate?
  4. When one of the sites goes down in a single VPLS instance, why is there traffic loss on another site?
  5. How can I control the behavior of VPLS class-based forwarding with multiple label-switched paths (LSPs) when one LSP goes down?
  6. What is the maximum number of VPLS instances supported, and the maximum number of sites supported per VPLS instance, on MX Series routers?
  7. How many Layer 2 circuits can be terminated into a single VRF instance?
  8. What are the Junos OS solutions for terminating <password> Layer 2 circuits into VPLS?
  9. What are the label-switched interface (LSI) label value assignments for different services?
  10. Which components are used in calculating the load balancing (hashing) algorithm for a link aggregation group?
  11. What is the interworking scalability for mesh groups in VPLS LDP-BGP?
  12. Is indirect next hop supported for VPLS in MX Series routers with I-chip-based DPCs?
  13. How can I define multiple port mirroring interfaces on a single chassis and select which traffic is mirrored to each interface on MX Series routers?
  14. What are the differences in packet processing between a VT interface and an LSI interface (vrf-table-label or no-tunnel-services)?
  15. Which classification methods are supported for ingress queuing on an Enhanced Queuing Dense Port Concentrator (EQ-DPC) on MX Series routers?