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

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Flexible BGP persistence

Updated: February 28, 2026

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Overview

Outlines flexible BGP persistence benefits, describes configuration of LLGR advertisement and activation for iBGP peers with default and peer-time settings, and presents enabling strategies for LLGR capabilities.

Flexible BGP persistence is a routing feature that

  • enhances network stability and resilience

  • enables Long-Lived Graceful Restart (LLGR) with flexible stale time management, and

  • allows controlled route distribution within the Autonomous System (AS).

This feature provides the flexibility to advertise LLGR stale routes to both LLGR-capable and non-LLGR-capable neighbors, ensuring continuous route availability during planned or unplanned restarts. It simplifies configuration by removing the need for manual timeout settings and enforces controlled route propagation by attaching specific BGP community attributes.

Table 1. Feature History Table

Feature Name

Release Name

Description
Flexible BGP Persistence Release 26.1.1

Introduced in this release on: Centralized Systems (8400 [ASIC: K100])(select variants only*)

* This feature is now supported on Cisco 8404-SYS-D routers.

Flexible BGP Persistence

 Release 25.4.1

Introduced in this release on: Fixed Systems (8010 [ASIC: A100])(select variants only*)

*This feature is now supported on:

  • 8011-32Y8L2H2FH

  • 8011-12G12X4Y-A

  • 8011-12G12X4Y-D

Flexible BGP Persistence

 Release 25.1.1

Introduced in this release on: Fixed Systems (8700 [ASIC: K100], 8010 [ASIC: A100])(select variants only*)

*This feature is supported on:

  • 8712-MOD-M

  • 8011-4G24Y4H-I
Flexible BGP Persistence Release 24.3.1

Introduced in this release on: Fixed Systems (8200 [ASIC: Q200, P100], 8700 [ASIC: P100]); Centralized Systems (8600 [ASIC:Q200]); Modular Systems (8800 [LC ASIC: Q100, Q200, P100])

Now you can ensure continuous connectivity by allowing non-Long Lived Graceful Restart (LLGR) eBGP neighbors to use LLGR stale routes, allowing for LLGR capability to be enabled and advertised without having to explicitly configure a timeout value, and gain greater flexibility in route management by advertising stale routes to non-LLGR peers through the NO_EXPORT community. This is an enhancement to the existing BGP Persistence feature.

The feature introduces these changes:

CLI:

  • The default , any , and advertise-internal-only keywords are added to the

    long-lived-graceful-restart command.

  • The fields Default advertised long-lived stale time, and Long-lived Graceful Restart Stale Time Accept Any are added to the show output of the show bgp command.

YANG Data Model:

*This feature is supported on:

  • 8212-48FH-M

  • 8711-32FH-M

  • 88-LC1-36EH

  • 88-LC1-12TH24FH-E

  • 88-LC1-52Y8H-EM

Benefits of flexible BGP persistence

Flexible BGP Persistence offers the following benefits:

  • Simplified configuration: Enables LLGR without manual timeout configuration using the long-lived-graceful-restart stale-time send default accept any command, which advertises a default stale time and accepts peer-specified stale times.

  • Enhanced network resilience: Allows LLGR stale routes to be advertised to non-LLGR eBGP neighbors, improving overall network robustness.

  • Enhanced network stability: Attaches the NO_EXPORT community and sets local preference to 0 for LLGR routes advertised to internal neighbors without LLGR capability, preventing stale routes from propagating beyond the local AS and ensuring they are not preferred over other routes.

Configure LLGR advertisement and activation with default and peer-time values

Enable and advertise Long-Lived Graceful Restart (LLGR) capability using default and peer-specified stale time values.

Before you begin

Ensure you have router BGP configuration access.

Procedure

1.

Enable and advertise LLGR capability with default and peer stale times.

Example:

Router(config)# router bgp 100
Router(config-bgp)# neighbor 10.1.1.1
Router(config-bgp-nbr)# address-family ipv4 unicast
Router(config-bgp-nbr-af)# long-lived-graceful-restart stale-time send default accept any

This command advertises LLGR capability with a default stale time of 172,800 seconds (2 days) and accepts any stale time value set by the peer.
2.

Use the show bgp neighbor to verify the LLGR configuration and stale time settings.

Example:

Router(config)# show bgp neighbor 192.0.2.254 
...
AF-dependent capabilities:
...
Long-lived Graceful Restart Stale Time Send Default is ON
Default advertised long-lived stale time is 172800 seconds
Long-lived Graceful Restart Stale Time Accept Any is ON
....

These output lines indicate these settings.

  • Long-lived Graceful Restart Stale Time Send Default is ON.

  • Default advertised long-lived stale time is 172800 seconds.

  • Long-lived Graceful Restart Stale Time Accept Any is ON.
LLGR capability is enabled on the BGP neighbor with default and peer-specified stale times successfully advertised and verified.

Enable LLGR capability and advertise it only to iBGP peers

Enable long lived graceful restart (LLGR) capability and restrict advertisement to iBGP peers.

Before you begin

Confirm BGP neighbor configuration.

Procedure

1.

Enable LLGR capability and advertise it only to iBGP peers:

Example:

Router(config)# router bgp 100
Router(config-bgp)# neighbor 10.1.1.1
Router(config-bgp-nbr)# address-family ipv4 unicast
Router(config-bgp-nbr-af)# long-lived-graceful-restart capable advertise-internal-only

This step sets the local preference to 0 and attaches the llgr-stale and no-export community attributes to limit route propagation within the local AS.
2.

Use the show bgp command to that the route is not preferred for outbound traffic within the AS, and that it will not be advertised to external BGP peers, thereby limiting its propagation to within the local AS.

Example:

Router# show bgp 10.1.1.1
Path #32: Received by speaker 0
…
192.0.2.254 (metric 30) from 10.1.1.1 (192.0.2.254)
Origin IGP, localpref 0, valid, internal, add-path
Received Path ID 40, Local Path ID 9, version 14321
Community: llgr-stale no-export
Originator: 192.0.2.254, Cluster list: 10.1.1.1

These output lines indicate these settings.

  • Local preference 0

  • Community attributes: llgr-stale no-export