MPLS study guide
MPLS · Work through your exam, one topic at a time.
The MPLS exam validates practical knowledge of Multiprotocol Label Switching as it is deployed in service provider and large enterprise networks. It suits network engineers, design and operations staff, and candidates moving from pure IP routing into label-switched transport, L3VPN and L2VPN services, traffic engineering, and modern Segment Routing evolution. The MPLS study guide has 10 sections and about 3,152 words.
01MPLS Fundamentals and Architecture
MPLS Fundamentals and Architecture tests the label-forwarding model: how the control plane builds bindings, how the data plane uses them, and where the shim header sits. You should distinguish an LER from an LSR and a LIB from an LFIB.
291 words, about 1 min02Label Distribution and Signalling Protocols (LDP, RSVP-TE)
Label Distribution and Signalling Protocols examines how routers exchange label bindings. LDP distributes labels for IGP prefixes; RSVP-TE distributes labels while also reserving bandwidth and carrying an explicit path for traffic-engineering tunnels.
306 words, about 2 min03Forwarding Plane
The Forwarding Plane domain tests data-plane mechanics after a label binding exists: how an incoming label selects an NHLFE, how the next hop is resolved, and how ECMP and adjacency affect forwarding. It is less about signaling and more about what the router does with a labeled packet.
342 words, about 2 min04Label Stack Operations and PHP
Label Stack Operations and PHP tests exact stack behavior: push, swap, pop, bottom-of-stack, implicit-null, explicit-null, and how service labels sit inside transport labels. You need to predict the label stack at each hop.
356 words, about 2 min05MPLS Layer 3 VPNs (VRF, MP-BGP, Route Targets)
MPLS Layer 3 VPNs tests the VRF, route distinguisher, route target, and MP-BGP VPNv4 model. You need to explain how overlapping customer prefixes remain separate and how a VPN label identifies the egress VRF.
311 words, about 2 min06MPLS Layer 2 VPNs and Pseudowires (LDP, BGP-AD, VPLS)
MPLS Layer 2 VPNs and Pseudowires tests how Ethernet or other Layer 2 frames are carried over MPLS. It covers point-to-point pseudowires signaled by LDP, autodiscovery with BGP-AD, and multipoint VPLS.
318 words, about 2 min07Traffic Engineering and QoS in MPLS
Traffic Engineering and QoS in MPLS tests constraint-based path selection, RSVP-TE tunnel attributes, and how MPLS carries QoS. You should distinguish TE metrics, admin groups, bandwidth reservations, and EXP/DiffServ handling.
301 words, about 2 min08MPLS Resilience, Fast Reroute and Protection
MPLS Resilience, Fast Reroute and Protection tests how MPLS recovers from link and node failures before IGP reconvergence. It covers RSVP-TE FRR, facility backup, one-to-one protection, LFA, and BFD.
301 words, about 2 min09Operations, Troubleshooting and Verification
Operations, Troubleshooting and Verification tests whether you can isolate control-plane versus data-plane faults. You should know which show commands prove a label binding, which prove an LFIB entry, and how to test a VRF path end to end.
311 words, about 2 min10Segment Routing and Modern MPLS Evolution
Segment Routing and Modern MPLS Evolution tests the SR-MPLS forwarding model and how it changes label distribution. You should understand SIDs, SRGB, node and adjacency SIDs, TI-LFA, and the roles of BGP-LU and EVPN.
315 words, about 2 min