openshift · dfitzmau · May 8, 2025 · ocpdocs-vale-bot · Dec 19, 2025 · ocpdocs-vale-bot
diff --git a/_topic_maps/_topic_map.yml b/_topic_maps/_topic_map.yml
@@ -1760,6 +1760,8 @@ Topics:
     File: verifying-connectivity-endpoint
   - Name: Changing the cluster network MTU
     File: changing-cluster-network-mtu
+  - Name: Network bonding considerations
+    File: network-bonding-considerations
   - Name: Using Stream Control Transmission Protocol
     File: using-sctp
   - Name: Associating secondary interfaces metrics to network attachments

diff --git a/installing/installing_bare_metal/ipi/ipi-install-installation-workflow.adoc b/installing/installing_bare_metal/ipi/ipi-install-installation-workflow.adoc
@@ -38,9 +38,6 @@ include::modules/creating-manifest-file-customized-br-ex-bridge.adoc[leveloffset
 // Scale each machine set to compute nodes
 include::modules/creating-scaling-machine-sets-compute-nodes-networking.adoc[leveloffset=+2]
 
-// Enabling OVS balance-slb mode for your cluster
-include::modules/enabling-OVS-balance-slb-mode.adoc[leveloffset=+1]
-
 // Establishing communication between subnets
 include::modules/ipi-install-establishing-communication-between-subnets.adoc[leveloffset=+1]
 

diff --git a/...ing/installing_bare_metal/upi/installing-bare-metal-network-customizations.adoc b/...ing/installing_bare_metal/upi/installing-bare-metal-network-customizations.adoc
@@ -84,9 +84,6 @@ include::modules/creating-manifest-file-customized-br-ex-bridge.adoc[leveloffset
 // Scale each machine set to compute nodes
 include::modules/creating-scaling-machine-sets-compute-nodes-networking.adoc[leveloffset=+2]
 
-// Enabling OVS balance-slb mode for your cluster
-include::modules/enabling-OVS-balance-slb-mode.adoc[leveloffset=+1]
-
 include::modules/installation-infrastructure-user-infra.adoc[leveloffset=+1]
 
 [role="_additional-resources"]

diff --git a/...alling/installing_bare_metal/upi/installing-restricted-networks-bare-metal.adoc b/...alling/installing_bare_metal/upi/installing-restricted-networks-bare-metal.adoc
@@ -99,9 +99,6 @@ include::modules/creating-manifest-file-customized-br-ex-bridge.adoc[leveloffset
 // Scale each machine set to compute nodes
 include::modules/creating-scaling-machine-sets-compute-nodes-networking.adoc[leveloffset=+2]
 
-// Enabling OVS balance-slb mode for your cluster
-include::modules/enabling-OVS-balance-slb-mode.adoc[leveloffset=+1]
-
 include::modules/installation-infrastructure-user-infra.adoc[leveloffset=+1]
 
 [role="_additional-resources"]

diff --git a/modules/configuring-localnet-switched-topology.adoc b/modules/configuring-localnet-switched-topology.adoc
@@ -9,7 +9,7 @@
 [role="_abstract"]
 The switched `localnet` topology interconnects the workloads created as Network Attachment Definitions (NADs) through a cluster-wide logical switch to a physical network.
 
-You must map a secondary network to the OVS bridge to use it as an OVN-Kubernetes secondary network. Bridge mappings allow network traffic to reach the physical network. A bridge mapping associates a physical network name, also known as an interface label, to a bridge created with Open vSwitch (OVS).
+You must map a secondary network to the ovs-bridge to use it as an OVN-Kubernetes secondary network. Bridge mappings allow network traffic to reach the physical network. A bridge mapping associates a physical network name, also known as an interface label, to a bridge created with Open vSwitch (OVS).
 
 You can create an `NodeNetworkConfigurationPolicy` (NNCP) object, part of the `nmstate.io/v1` API group, to declaratively create the mapping. This API is provided by the NMState Operator. By using this API you can apply the bridge mapping to nodes that match your specified `nodeSelector` expression, such as `node-role.kubernetes.io/worker: ''`. With this declarative approach, the NMState Operator applies secondary network configuration to all nodes specified by the node selector automatically and transparently.
 
@@ -18,6 +18,11 @@ When attaching a secondary network, you can either use the existing `br-ex` brid
 - If your nodes include only a single network interface, you must use the existing bridge. This network interface is owned and managed by OVN-Kubernetes and you must not remove it from the `br-ex` bridge or alter the interface configuration. If you remove or alter the network interface, your cluster network stops working correctly.
 - If your nodes include several network interfaces, you can attach a different network interface to a new bridge, and use that for your secondary network. This approach provides for traffic isolation from your primary cluster network.
 
+[NOTE]
+====
+As a postinstallation task, you cannot make configuration changes to the `br-ex` bridge or its underlying interfaces in the `NodeNetworkConfigurationPolicy` (NNCP) resource. As a workaround, use a secondary network interface connected to your host or switch.
+====
+
 The `localnet1` network is mapped to the `br-ex` bridge in the following sharing-a-bridge example:
 
 [source,yaml]
@@ -35,17 +40,16 @@ spec:
       - localnet: localnet1
         bridge: br-ex
         state: present
-# ...
 ----
-
++
 where:
-
-`name`:: The name for the configuration object.
++
+`metadata.name`:: The name for the configuration object.
 `node-role.kubernetes.io/worker`:: A node selector that specifies the nodes to apply the node network configuration policy to.
 `localnet`:: The name for the secondary network from which traffic is forwarded to the OVS bridge. This secondary network must match the name of the `spec.config.name` field of the `NetworkAttachmentDefinition` CRD that defines the OVN-Kubernetes secondary network.
 `bridge`:: The name of the OVS bridge on the node. This value is required only if you specify `state: present`.
 `state`:: The state for the mapping. Must be either `present` to add the bridge or `absent` to remove the bridge. The default value is `present`.
-
++
 The following JSON example configures a localnet secondary network that is named `localnet1`. Note that the value for the `mtu` parameter must match the MTU value that was set for the secondary network interface that is mapped to the `br-ex` bridge interface.
 
 [source,json]
@@ -96,18 +100,18 @@ spec:
         bridge: ovs-br1
         state: present
 ----
-
++
 where:
-
-`name`:: Specifies the name of the configuration object.
++
+`metadata.name`:: Specifies the name of the configuration object.
 `node-role.kubernetes.io/worker`:: Specifies a node selector that identifies the nodes to which the node network configuration policy applies.
 `interfaces.name`:: Specifies a new OVS bridge that operates separately from the default bridge used by OVN-Kubernetes for cluster traffic.
 `mcast-snooping-enable`:: Specifies whether to enable multicast snooping. When enabled, multicast snooping prevents network devices from flooding multicast traffic to all network members. By default, an OVS bridge does not enable multicast snooping. The default value is `false`.
-``port.name`:: Specifies the network device on the host system to associate with the new OVS bridge.
-`bridge-mappings.localnet`:: Specifies the name of the secondary network that forwards traffic to the OVS bridge. This name must match the value of the `spec.config.name` field in the `NetworkAttachmentDefinition` CRD that defines the OVN-Kubernetes secondary network.
-`bridge-mappings.bridge`:: Specifies the name of the OVS bridge on the node. The value is required only when `state: present` is set.
-`bridge-mappings.state`:: Specifies the state of the mapping. Valid values are `present` to add the bridge or `absent` to remove the bridge. The default value is `present`.
-
+`port.name`:: Specifies the network device on the host system to associate with the new OVS bridge.
+`localnet`:: Specifies the name of the secondary network that forwards traffic to the OVS bridge. This name must match the value of the `spec.config.name` field in the `NetworkAttachmentDefinition` CRD that defines the OVN-Kubernetes secondary network.
+`bridge`:: Specifies the name of the OVS bridge on the node. The value is required only when `state: present` is set.
+`state`:: Specifies the state of the mapping. Valid values are `present` to add the bridge or `absent` to remove the bridge. The default value is `present`.
++
 The following JSON example configures a localnet secondary network that is named `localnet2`. Note that the value for the `mtu` parameter must match the MTU value that was set for the `eth1` secondary network interface.
 
 [source,json]
@@ -125,4 +129,3 @@ The following JSON example configures a localnet secondary network that is named
   "excludeSubnets": "10.100.200.0/29"
 }
 ----
-
diff --git a/modules/configuring-ovnk-use-second-ovs-bridge.adoc b/modules/configuring-ovnk-use-second-ovs-bridge.adoc
@@ -6,6 +6,7 @@
 [id="configuring-ovnk-use-second-ovs-bridge_{context}"]
 = Configuring OVN-Kubernetes to use a secondary OVS bridge
 
+[role="_abstract"]
 You can create an additional or _secondary_ Open vSwitch (OVS) bridge, `br-ex1`, that OVN-Kubernetes manages and the Multiple External Gateways (MEG) implementation uses for defining external gateways for an {product-title} node. You can define a MEG in an `AdminPolicyBasedExternalRoute` custom resource (CR). The MEG implementation provides a pod with access to multiple gateways, equal-cost multipath (ECMP) routes, and the Bidirectional Forwarding Detection (BFD) implementation.
 
 Consider a use case for pods impacted by the Multiple External Gateways (MEG) feature and you want to egress traffic to a different interface, for example `br-ex1`, on a node. Egress traffic for pods not impacted by MEG get routed to the default OVS `br-ex` bridge.
@@ -17,6 +18,11 @@ Currently, MEG is unsupported for use with other egress features, such as egress
 
 You must define the additional bridge in an interface definition of a machine configuration manifest file. The Machine Config Operator uses the manifest to create a new file at `/etc/ovnk/extra_bridge` on the host. The new file includes the name of the network interface that the additional OVS bridge configures for a node.
 
+[IMPORTANT]
+====
+Do not use the `nmstate` API to make configuration changes to the secondary interface that is defined in the `/etc/ovnk/extra_bridge` directory path. The `configure-ovs.sh` configuration script creates and manages OVS bridge interfaces, so any interruptive changes to these interfaces by the `nmstate` API can lead to network configuration instability.
+====
+
 After you create and edit the manifest file, the Machine Config Operator completes tasks in the following order:
 
 . Drains nodes in singular order based on the selected machine configuration pool.
@@ -39,9 +45,9 @@ For more information about useful situations for the additional `br-ex1` bridge
 +
 [IMPORTANT]
 ====
-Do not use the Kubernetes NMState Operator to define or a `NodeNetworkConfigurationPolicy` (NNCP) manifest file to define the additional interface.
+Do not use the Kubernetes NMState Operator or a `NodeNetworkConfigurationPolicy` (NNCP) manifest file to define the additional interface. Ensure that the additional interface or sub-interfaces when defining a `bond` interface are not used by an existing `br-ex` OVN Kubernetes network deployment.
 
-Also ensure that the additional interface or sub-interfaces when defining a `bond` interface are not used by an existing `br-ex` OVN Kubernetes network deployment.
+As a postinstallation task, you cannot make configuration changes to the `br-ex` bridge or its underlying interfaces. As a workaround, use a secondary network interface connected to your host or switch.
 ====
 +
 .. Create the following interface definition files. These files get added to a machine configuration manifest file so that host nodes can access the definition files. 

diff --git a/modules/enable-active-backup-mode.adoc b/modules/enable-active-backup-mode.adoc
@@ -0,0 +1,16 @@
+// Module included in the following assemblies:
+//
+// * networking/advanced_networking/network-bonding-considerations.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="enable-active-backup-mode_{context}"]
+= Enable active-backup mode for your cluster
+
+[role="_abstract"]
+The `active-backup` mode provides fault tolerance for network connections by switching to a backup link where the primary link fails. The mode specifies the following ports for your cluster:
+
+* An active port where one physical interface sends and receives traffic at any given time.
+* A standby port where all other ports act as backup links and continously monitor their link status.
+
+During a failover process, if an active port or its link fails, the bonding logic switches all network traffic to a standby port. This standby port becomes the new active port. For failover to work, all ports in a bond must share the same Media Access Control (MAC) address. 
+
diff --git a/modules/installation-network-user-infra.adoc b/modules/installation-network-user-infra.adoc
@@ -74,6 +74,7 @@ endif::[]
 [id="installation-network-user-infra_{context}"]
 = Networking requirements for user-provisioned infrastructure
 
+[role="_abstract"]
 All the {op-system-first} machines require networking to be configured in `initramfs` during boot
 to fetch their Ignition config files.
 
@@ -94,17 +95,13 @@ During the initial boot, the machines require an IP address configuration that i
 
 [NOTE]
 ====
-* It is recommended to use a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.
+* Consider using a DHCP server for long-term management of the cluster machines. Ensure that the DHCP server is configured to provide persistent IP addresses, DNS server information, and hostnames to the cluster machines.
 
 * If a DHCP service is not available for your user-provisioned infrastructure, you can instead provide the IP networking configuration and the address of the DNS server to the nodes at {op-system} install time. These can be passed as boot arguments if you are installing from an ISO image. See the _Installing {op-system} and starting the {product-title} bootstrap process_ section for more information about static IP provisioning and advanced networking options.
 ====
 endif::ibm-z[]
 
-The Kubernetes API server must be able to resolve the node names of the cluster
-machines. If the API servers and worker nodes are in different zones, you can
-configure a default DNS search zone to allow the API server to resolve the
-node names. Another supported approach is to always refer to hosts by their
-fully-qualified domain names in both the node objects and all DNS requests.
+The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.
 endif::azure,gcp[]
 
 ifndef::ibm-z,azure[]
@@ -119,9 +116,7 @@ endif::ibm-z,azure[]
 [id="installation-network-connectivity-user-infra_{context}"]
 == Network connectivity requirements
 
-You must configure the network connectivity between machines to allow {product-title} cluster
-components to communicate. Each machine must be able to resolve the hostnames
-of all other machines in the cluster.
+You must configure the network connectivity between machines to allow {product-title} cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.
 
 This section provides details about the ports that are required.
 

diff --git a/modules/installation-user-infra-machines-static-network.adoc b/modules/installation-user-infra-machines-static-network.adoc
@@ -45,6 +45,7 @@ endif::[]
 [id="installation-user-infra-machines-static-network_{context}"]
 = Advanced {op-system} installation reference
 
+[role="_abstract"]
 This section illustrates the networking configuration and other advanced options that allow you to modify the {op-system-first} manual installation process. The following tables describe the kernel arguments and command-line options you can use with the {op-system} live installer and the `coreos-installer` command.
 
 [id="installation-user-infra-machines-routing-bonding_{context}"]
@@ -172,7 +173,6 @@ ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
 ip=::::core0.example.com:enp2s0:none
 ----
 
-
 === Combining DHCP and static IP configurations
 
 You can combine DHCP and static IP configurations on systems with multiple network interfaces, for example:
@@ -183,7 +183,6 @@ ip=enp1s0:dhcp
 ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
 ----
 
-
 === Configuring VLANs on individual interfaces
 
 Optional: You can configure VLANs on individual interfaces by using the `vlan=` parameter.
@@ -220,7 +219,9 @@ ifndef::ibm-z-kvm[]
 
 === Bonding multiple network interfaces to a single interface
 
-Optional: You can bond multiple network interfaces to a single interface by using the `bond=` option. Refer to the following examples:
+As an optional configuration, you can bond multiple network interfaces to a single interface by using the `bond=` option. To apply this configuration to your cluster, complete the procedure steps for each node that runs on your cluster.
+
+.Procedure
 
 * The syntax for configuring a bonded interface is: `bond=<name>[:<network_interfaces>][:options]`
 +
@@ -229,30 +230,28 @@ and _options_ is a comma-separated list of bonding options. Enter `modinfo bondi
 
 * When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other
 information for the bonded interface.
-
++
 ** To configure the bonded interface to use DHCP, set the bond's IP address to `dhcp`. For example:
 +
 [source,terminal]
 ----
-bond=bond0:em1,em2:mode=active-backup
 ip=bond0:dhcp
 ----
-
++
 ** To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example:
 ifndef::ibm-z[]
 +
 [source,terminal]
 ----
-bond=bond0:em1,em2:mode=active-backup
 ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
 ----
 endif::ibm-z[]
 ifdef::ibm-z[]
-
++
 [source,terminal]
 ----
-bond=bond0:em1,em2:mode=active-backup,fail_over_mac=1
-ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
+bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none::AA:BB:CC:DD:EE:FF ip=em1:none::AA:BB:CC:DD:EE:FF
+ip=em2:none::AA:BB:CC:DD:EE:FF
 ----
 
 Always set the `fail_over_mac=1` option in active-backup mode, to avoid problems when shared OSA/RoCE cards are used.
@@ -287,9 +286,9 @@ ifndef::ibm-z[]
 
 === Bonding multiple SR-IOV network interfaces to a dual port NIC interface
 
-Optional: You can bond multiple SR-IOV network interfaces to a dual port NIC interface by using the `bond=` option.
+As an optional configuration, you can bond multiple SR-IOV network interfaces to a dual port NIC interface by using the `bond=` option.
 
-On each node, you must perform the following tasks:
+.Procedure
 
 ifndef::installing-ibm-power[]
 . Create the SR-IOV virtual functions (VFs) following the guidance in link:https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/configuring_and_managing_virtualization/managing-virtual-devices_configuring-and-managing-virtualization#managing-sr-iov-devices_managing-virtual-devices[Managing SR-IOV devices]. Follow the procedure in the "Attaching SR-IOV networking devices to virtual machines" section.
@@ -308,12 +307,14 @@ The following examples illustrate the syntax you must use:
 
 * When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other information for the bonded interface.
 
-** To configure the bonded interface to use DHCP, set the bond's IP address to `dhcp`. For example:
+** To configure the bonded interface to use DHCP, set the `ip` parameter to `dhcp` as demonstrated in the following example:
 +
 [source,terminal]
 ----
 bond=bond0:eno1f0,eno2f0:mode=active-backup
-ip=bond0:dhcp
+ip=bond0:dhcp::AA:BB:CC:DD:EE:FF
+ip=eno1f0:none::AA:BB:CC:DD:EE:FF
+ip=eno2f0:none::AA:BB:CC:DD:EE:FF
 ----
 
 ** To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: