BGP Configuration Guide for Cisco 8000 Series Routers, Cisco IOS XR Releases

BGP Prefix Management and Session Parameters

Updated: February 28, 2026

Overview

Describes BGP prefix control and session-level configurations that optimize network performance by managing maximum prefix limits, discarding extra paths, and customizing TCP maximum segment size.

You will learn about BGP prefix control, path management techniques, and how to customize session-level settings like TCP MSS to enhance network performance and reliability.

BGP maximum-prefix and discard extra paths

Describes how BGP maximum-prefix limits the number of prefixes received from a neighbor and terminates the session if exceeded, while discard extra paths drops excess prefixes without session flapping to maintain stability.

TCP maximum segment size

Describes TCP maximum segment size as a negotiated attribute that optimizes data transfer efficiency by controlling the largest unfragmented TCP segment size based on interface MTU.

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