[PATCH pve-docs v3 44/45] sdn: zones: document the VXLAN-GBP option

[Hannes Laimer <h.laimer@proxmox.com>]

EVPN zones run on VXLAN interfaces as well, so the EVPN section gets
the same entry as the VXLAN one.

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---
 pvesdn.adoc | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/pvesdn.adoc b/pvesdn.adoc
index 3fd3533ad07f..7a674597d470 100644
--- a/pvesdn.adoc
+++ b/pvesdn.adoc
@@ -310,6 +310,18 @@ SDN Fabric:: Instead of manually defining all the peers, use a
 MTU:: Because VXLAN encapsulation uses 50 bytes, the MTU needs to be 50 bytes
   lower than the outgoing physical interface.
 
+VXLAN-GBP:: Enable VXLAN Group Based Policy (GBP) on the zone's VXLAN
+  interfaces. GBP carries a 16-bit group ID in the VXLAN header, taken from
+  the packet mark on the sending node and restored on the receiving one.
+  Every VTEP in the zone must have it enabled, since one without it drops
+  GBP-tagged traffic. All zones that use the same VXLAN port must agree on
+  this option, an SDN apply refuses a configuration where they do not.
+  Optional.
+
+NOTE: The kernel sets GBP only when it creates a VXLAN interface. Changing the
+option on an existing zone therefore recreates the zone's VXLAN interfaces on
+the next apply, which briefly interrupts traffic.
+
 
 [[pvesdn_zone_plugin_evpn]]
 EVPN Zones
@@ -371,6 +383,18 @@ MTU:: Because VXLAN encapsulation uses 50 bytes, the MTU needs to be 50 bytes
   less than the maximal MTU of the outgoing physical interface.  Optional,
   defaults to 1450.
 
+VXLAN-GBP:: Enable VXLAN Group Based Policy (GBP) on the zone's VXLAN
+  interfaces. GBP carries a 16-bit group ID in the VXLAN header, taken from
+  the packet mark on the sending node and restored on the receiving one.
+  Every VTEP in the zone must have it enabled, since one without it drops
+  GBP-tagged traffic. All zones that use the same VXLAN port must agree on
+  this option, an SDN apply refuses a configuration where they do not.
+  Optional.
+
+NOTE: The kernel sets GBP only when it creates a VXLAN interface. Changing the
+option on an existing zone therefore recreates the zone's VXLAN interfaces on
+the next apply, which briefly interrupts traffic.
+
 
 [[pvesdn_config_vnet]]
 VNets
-- 
2.47.3