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

BGP update groups

Updated: February 28, 2026

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Overview

Describes the mechanism that groups BGP neighbors with similar outbound policies to optimize update message generation and improve network performance.

A BGP update group is a mechanism that

groups BGP neighbors with similar outbound routing policies
enables efficient update message generation, and
automatically recalculates group membership when configuration changes occur.

BGP update group generation separates update message creation from neighbor configuration by using an algorithm to assign neighbors to groups based on their outbound policies. This process operates automatically without requiring manual configuration. With update group-based message generation, the router sends a single update message to all neighbors in a group, which simplifies management, reduces redundant updates, and improves overall network performance.

How BGP update group membership and optimization work

Summary

The key components involved in the process are:

Router: Applies outbound policies and manages update groups.
BGP neighbors: Are assigned to update groups based on their outbound routing policies.
Update group algorithm: Dynamically calculates group membership and manages update message generation.

BGP update group membership is recalculated automatically whenever there is a configuration change. The router ensures that neighbors with matching outbound routing policies are grouped together, which helps reduce processing and optimize updates.

Workflow

These stages describe how BGP update group membership and optimization work.

The router detects a configuration change.
The update group algorithm recalculates group memberships based on current outbound policies.
The router generates update messages for each group and sends them to the appropriate neighbors.

Result

The router delivers optimized BGP updates, reducing redundancy and improving overall network efficiency.

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