From 452bac3a448a463b612a9dfc71355be8a77c10a8 Mon Sep 17 00:00:00 2001 From: cumulusAnia Date: Fri, 31 Jan 2025 07:46:45 -0800 Subject: [PATCH] updates to PIC --- .../Optional-BGP-Configuration.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/content/cumulus-linux-512/Layer-3/Border-Gateway-Protocol-BGP/Optional-BGP-Configuration.md b/content/cumulus-linux-512/Layer-3/Border-Gateway-Protocol-BGP/Optional-BGP-Configuration.md index 782ed1f37b..9380dba0d2 100644 --- a/content/cumulus-linux-512/Layer-3/Border-Gateway-Protocol-BGP/Optional-BGP-Configuration.md +++ b/content/cumulus-linux-512/Layer-3/Border-Gateway-Protocol-BGP/Optional-BGP-Configuration.md @@ -1382,9 +1382,9 @@ cumulus@leaf01:~$ ## BGP Prefix Independent Convergence -BGP prefix independent convergence (PIC) reduces convergence times and improves unicast traffic convergence for remote link and node failures (when the BGP next hop fails) regardless of route scale (for example, for changes in individual routes). A remote link is a link between a spine and a remote leaf, or a spine and the super spine layer. +BGP prefix independent convergence (PIC) reduces convergence times and improves unicast traffic convergence for remote link and node failures (when the BGP next hop fails) regardless of route scale. A remote link is a link between a spine and a remote leaf, or a spine and the super spine layer. -When you configure BGP PIC, Cumulus Linux assigns one next hop group for each source and the remote leaf advertises the router ID loopback route. The remote leaf tags prefix routes with a route-origin extended community (SOO) so that the local leaf recognizes the routes. When the network topology changes, the local leaf obtains the router ID loopback route with the updated ECMP, allowing a O (1) next hop group replace operation for all prefixes from the remote leaf without waiting for individual BGP updates. +When you configure BGP PIC, Cumulus Linux assigns one next hop group for each source and the remote leaf advertises a route with a prefix derived from the router ID. The remote leaf tags prefix routes with a route-origin extended community (SOO) so that the local leaf recognizes the routes. When the network topology changes, the local leaf obtains the router ID route with the updated ECMP, allowing a O (1) next hop group replace operation for all prefixes from the remote leaf without waiting for individual BGP updates. {{%notice note%}} - Cumulus Linux supports BGP PIC on Spectrum-4 switches. @@ -1401,7 +1401,7 @@ When you configure BGP PIC, Cumulus Linux assigns one next hop group for each so To configure PIC: - **On a leaf only**, enable the BGP advertise origin option so that BGP can attach the SOO extended community to all routes advertised to its peers from the source where the routes originate. - **On all switches**, enable the BGP next hop group per source option so that when BGP receives routes with the SOO extended community, it allocates a next hop group for each source. -- **On a spine and super spine**, set the {{}} BGP convergence wait time to 30 and the convergence wait establish wait time to 15. These exact settings are required for PIC to work correctly. +- **On a spine and super spine**, set the {{}} BGP convergence wait time to 30 and the convergence wait establish wait time to 15. These are the minimum recommended timer settings to ensure optimal convergence when using PIC. {{%notice note%}} Changing the BGP advertise origin option or the BGP next hop group per source option can cause traffic disruption.