About This Flashcard Deck
This flashcard deck contains 10 cards covering key SP Core concepts for the SPCOR exam. Test your service provider networking knowledge. Use active recall by attempting to answer each question before revealing the answer.
Question
What is the difference between RD and RT in MPLS L3VPN?
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Answer
RD (Route Distinguisher): makes VPNv4 routes unique. RT (Route Target): controls import/export between VRFs.
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All SP Core Flashcards
Q: What is the difference between RD and RT in MPLS L3VPN?
A: RD (Route Distinguisher): makes VPNv4 routes unique. RT (Route Target): controls import/export between VRFs.
Q: What is Segment Routing?
A: Source routing paradigm: path encoded as a list of segments in the packet header. No per-flow state in the network. Uses MPLS or IPv6 (SRv6).
Q: What is VPLS?
A: Virtual Private LAN Service — multipoint L2VPN that emulates an Ethernet LAN across an MPLS backbone.
Q: What is the difference between IS-IS and OSPF in SP networks?
A: IS-IS: protocol-independent (runs on L2), scales better for large SP networks, simpler flooding. OSPF: IP-based, more feature-rich, common in enterprise.
Q: What is RPKI?
A: Resource Public Key Infrastructure — validates BGP route origin authenticity using ROA (Route Origin Authorization) certificates.
Q: What is PHP in MPLS?
A: Penultimate Hop Popping — the second-to-last router removes the MPLS label so the last router only does IP lookup.
Q: What is BCP38?
A: Best Current Practice 38 — anti-spoofing: filter packets with source addresses not from your network at ingress.
Q: What is a PE router in MPLS?
A: Provider Edge — connects to customer CE routers. Maintains VRFs and performs MPLS encapsulation/decapsulation.
Q: What is model-driven telemetry?
A: Push-based monitoring using YANG models. Device streams data to collector at configured intervals — more efficient than SNMP polling.
Q: What is DiffServ QoS?
A: Differentiated Services — classifies and marks packets (DSCP), then applies per-hop behaviors (PHB): EF (voice), AF (assured forwarding), BE (best effort).
Cisco Flashcard Study Strategy
Cisco exams heavily test protocol operations and configuration details. Use these flashcards to drill port numbers, protocol behaviours, and administrative distances. Pair flashcard sessions with Packet Tracer labs — when you encounter a card about OSPF neighbour states, open a lab and verify each state transition on a live topology. This combination of memorisation and practice builds the deep understanding Cisco exams demand.