Understanding BGP Link State (BGP-LS)
# What is BGP-LS?
* BGP-LS (BGP Link-State) is an extension of BGP that allows routers to exchange network topology information via Link-State NLRI.
* Helps SDN controllers and path computation elements (PCEs) make intelligent routing decisions.
# What Does BGP-LS Advertise?# Node Information - Router IDs, Loopbacks# Link Information - Bandwidth, Delay, Cost# Prefix Information - Network Subnets# Topology Information - Full network graph Why is the Answer TRUE?
# BGP-LS introduces a new NLRI format for advertising link-state information.# NLRI (Network Layer Reachability Information) is used to distribute topology data to SDN controllers.# It improves path optimization by enabling centralized traffic engineering decisions.
Real-World Application:
* SDN-Based Traffic Engineering: Used in Segment Routing (SR) networks for centralized path selection.
* MPLS TE (Traffic Engineering): Optimizes network paths dynamically based on real-time link-state data.
# Reference: Huawei HCIE-Datacom Guide - BGP Link-State (BGP-LS) Fundamentals